You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
12231 lines
376 KiB
12231 lines
376 KiB
|
|
/* pngvalid.c - validate libpng by constructing then reading png files. |
|
* |
|
* Last changed in libpng 1.6.31 [July 27, 2017] |
|
* Copyright (c) 2014-2017 John Cunningham Bowler |
|
* |
|
* This code is released under the libpng license. |
|
* For conditions of distribution and use, see the disclaimer |
|
* and license in png.h |
|
* |
|
* NOTES: |
|
* This is a C program that is intended to be linked against libpng. It |
|
* generates bitmaps internally, stores them as PNG files (using the |
|
* sequential write code) then reads them back (using the sequential |
|
* read code) and validates that the result has the correct data. |
|
* |
|
* The program can be modified and extended to test the correctness of |
|
* transformations performed by libpng. |
|
*/ |
|
|
|
#define _POSIX_SOURCE 1 |
|
#define _ISOC99_SOURCE 1 /* For floating point */ |
|
#define _GNU_SOURCE 1 /* For the floating point exception extension */ |
|
#define _BSD_SOURCE 1 /* For the floating point exception extension */ |
|
#define _DEFAULT_SOURCE 1 /* For the floating point exception extension */ |
|
|
|
#include <signal.h> |
|
#include <stdio.h> |
|
|
|
#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) |
|
# include <config.h> |
|
#endif |
|
|
|
#ifdef HAVE_FEENABLEEXCEPT /* from config.h, if included */ |
|
# include <fenv.h> |
|
#endif |
|
|
|
#ifndef FE_DIVBYZERO |
|
# define FE_DIVBYZERO 0 |
|
#endif |
|
#ifndef FE_INVALID |
|
# define FE_INVALID 0 |
|
#endif |
|
#ifndef FE_OVERFLOW |
|
# define FE_OVERFLOW 0 |
|
#endif |
|
|
|
/* Define the following to use this test against your installed libpng, rather |
|
* than the one being built here: |
|
*/ |
|
#ifdef PNG_FREESTANDING_TESTS |
|
# include <png.h> |
|
#else |
|
# include "../../png.h" |
|
#endif |
|
|
|
#ifdef PNG_ZLIB_HEADER |
|
# include PNG_ZLIB_HEADER |
|
#else |
|
# include <zlib.h> /* For crc32 */ |
|
#endif |
|
|
|
/* 1.6.1 added support for the configure test harness, which uses 77 to indicate |
|
* a skipped test, in earlier versions we need to succeed on a skipped test, so: |
|
*/ |
|
#if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H) |
|
# define SKIP 77 |
|
#else |
|
# define SKIP 0 |
|
#endif |
|
|
|
/* pngvalid requires write support and one of the fixed or floating point APIs. |
|
*/ |
|
#if defined(PNG_WRITE_SUPPORTED) &&\ |
|
(defined(PNG_FIXED_POINT_SUPPORTED) || defined(PNG_FLOATING_POINT_SUPPORTED)) |
|
|
|
#if PNG_LIBPNG_VER < 10500 |
|
/* This deliberately lacks the const. */ |
|
typedef png_byte *png_const_bytep; |
|
|
|
/* This is copied from 1.5.1 png.h: */ |
|
#define PNG_INTERLACE_ADAM7_PASSES 7 |
|
#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7) |
|
#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7) |
|
#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3) |
|
#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3) |
|
#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\ |
|
-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass)) |
|
#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\ |
|
-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass)) |
|
#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \ |
|
(((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass)) |
|
#define PNG_COL_FROM_PASS_COL(xIn, pass) \ |
|
(((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass)) |
|
#define PNG_PASS_MASK(pass,off) ( \ |
|
((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \ |
|
((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U)) |
|
#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \ |
|
((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1) |
|
#define PNG_COL_IN_INTERLACE_PASS(x, pass) \ |
|
((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1) |
|
|
|
/* These are needed too for the default build: */ |
|
#define PNG_WRITE_16BIT_SUPPORTED |
|
#define PNG_READ_16BIT_SUPPORTED |
|
|
|
/* This comes from pnglibconf.h after 1.5: */ |
|
#define PNG_FP_1 100000 |
|
#define PNG_GAMMA_THRESHOLD_FIXED\ |
|
((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1)) |
|
#endif |
|
|
|
#if PNG_LIBPNG_VER < 10600 |
|
/* 1.6.0 constifies many APIs, the following exists to allow pngvalid to be |
|
* compiled against earlier versions. |
|
*/ |
|
# define png_const_structp png_structp |
|
#endif |
|
|
|
#ifndef RELEASE_BUILD |
|
/* RELEASE_BUILD is true for releases and release candidates: */ |
|
# define RELEASE_BUILD (PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC) |
|
#endif |
|
#if RELEASE_BUILD |
|
# define debugonly(something) |
|
#else /* !RELEASE_BUILD */ |
|
# define debugonly(something) something |
|
#endif /* !RELEASE_BUILD */ |
|
|
|
#include <float.h> /* For floating point constants */ |
|
#include <stdlib.h> /* For malloc */ |
|
#include <string.h> /* For memcpy, memset */ |
|
#include <math.h> /* For floor */ |
|
|
|
/* Convenience macros. */ |
|
#define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) |
|
#define CHUNK_IHDR CHUNK(73,72,68,82) |
|
#define CHUNK_PLTE CHUNK(80,76,84,69) |
|
#define CHUNK_IDAT CHUNK(73,68,65,84) |
|
#define CHUNK_IEND CHUNK(73,69,78,68) |
|
#define CHUNK_cHRM CHUNK(99,72,82,77) |
|
#define CHUNK_gAMA CHUNK(103,65,77,65) |
|
#define CHUNK_sBIT CHUNK(115,66,73,84) |
|
#define CHUNK_sRGB CHUNK(115,82,71,66) |
|
|
|
/* Unused formal parameter errors are removed using the following macro which is |
|
* expected to have no bad effects on performance. |
|
*/ |
|
#ifndef UNUSED |
|
# if defined(__GNUC__) || defined(_MSC_VER) |
|
# define UNUSED(param) (void)param; |
|
# else |
|
# define UNUSED(param) |
|
# endif |
|
#endif |
|
|
|
/***************************** EXCEPTION HANDLING *****************************/ |
|
#ifdef PNG_FREESTANDING_TESTS |
|
# include <cexcept.h> |
|
#else |
|
# include "../visupng/cexcept.h" |
|
#endif |
|
|
|
#ifdef __cplusplus |
|
# define this not_the_cpp_this |
|
# define new not_the_cpp_new |
|
# define voidcast(type, value) static_cast<type>(value) |
|
#else |
|
# define voidcast(type, value) (value) |
|
#endif /* __cplusplus */ |
|
|
|
struct png_store; |
|
define_exception_type(struct png_store*); |
|
|
|
/* The following are macros to reduce typing everywhere where the well known |
|
* name 'the_exception_context' must be defined. |
|
*/ |
|
#define anon_context(ps) struct exception_context *the_exception_context = \ |
|
&(ps)->exception_context |
|
#define context(ps,fault) anon_context(ps); png_store *fault |
|
|
|
/* This macro returns the number of elements in an array as an (unsigned int), |
|
* it is necessary to avoid the inability of certain versions of GCC to use |
|
* the value of a compile-time constant when performing range checks. It must |
|
* be passed an array name. |
|
*/ |
|
#define ARRAY_SIZE(a) ((unsigned int)((sizeof (a))/(sizeof (a)[0]))) |
|
|
|
/* GCC BUG 66447 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66447) requires |
|
* some broken GCC versions to be fixed up to avoid invalid whining about auto |
|
* variables that are *not* changed within the scope of a setjmp being changed. |
|
* |
|
* Feel free to extend the list of broken versions. |
|
*/ |
|
#define is_gnu(major,minor)\ |
|
(defined __GNUC__) && __GNUC__ == (major) && __GNUC_MINOR__ == (minor) |
|
#define is_gnu_patch(major,minor,patch)\ |
|
is_gnu(major,minor) && __GNUC_PATCHLEVEL__ == 0 |
|
/* For the moment just do it always; all versions of GCC seem to be broken: */ |
|
#ifdef __GNUC__ |
|
const void * volatile make_volatile_for_gnu; |
|
# define gnu_volatile(x) make_volatile_for_gnu = &x; |
|
#else /* !GNUC broken versions */ |
|
# define gnu_volatile(x) |
|
#endif /* !GNUC broken versions */ |
|
|
|
/******************************* UTILITIES ************************************/ |
|
/* Error handling is particularly problematic in production code - error |
|
* handlers often themselves have bugs which lead to programs that detect |
|
* minor errors crashing. The following functions deal with one very |
|
* common class of errors in error handlers - attempting to format error or |
|
* warning messages into buffers that are too small. |
|
*/ |
|
static size_t safecat(char *buffer, size_t bufsize, size_t pos, |
|
const char *cat) |
|
{ |
|
while (pos < bufsize && cat != NULL && *cat != 0) |
|
buffer[pos++] = *cat++; |
|
|
|
if (pos >= bufsize) |
|
pos = bufsize-1; |
|
|
|
buffer[pos] = 0; |
|
return pos; |
|
} |
|
|
|
static size_t safecatn(char *buffer, size_t bufsize, size_t pos, int n) |
|
{ |
|
char number[64]; |
|
sprintf(number, "%d", n); |
|
return safecat(buffer, bufsize, pos, number); |
|
} |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
static size_t safecatd(char *buffer, size_t bufsize, size_t pos, double d, |
|
int precision) |
|
{ |
|
char number[64]; |
|
sprintf(number, "%.*f", precision, d); |
|
return safecat(buffer, bufsize, pos, number); |
|
} |
|
#endif |
|
|
|
static const char invalid[] = "invalid"; |
|
static const char sep[] = ": "; |
|
|
|
static const char *colour_types[8] = |
|
{ |
|
"grayscale", invalid, "truecolour", "indexed-colour", |
|
"grayscale with alpha", invalid, "truecolour with alpha", invalid |
|
}; |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
/* Convert a double precision value to fixed point. */ |
|
static png_fixed_point |
|
fix(double d) |
|
{ |
|
d = floor(d * PNG_FP_1 + .5); |
|
return (png_fixed_point)d; |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* Generate random bytes. This uses a boring repeatable algorithm and it |
|
* is implemented here so that it gives the same set of numbers on every |
|
* architecture. It's a linear congruential generator (Knuth or Sedgewick |
|
* "Algorithms") but it comes from the 'feedback taps' table in Horowitz and |
|
* Hill, "The Art of Electronics" (Pseudo-Random Bit Sequences and Noise |
|
* Generation.) |
|
*/ |
|
static void |
|
make_random_bytes(png_uint_32* seed, void* pv, size_t size) |
|
{ |
|
png_uint_32 u0 = seed[0], u1 = seed[1]; |
|
png_bytep bytes = voidcast(png_bytep, pv); |
|
|
|
/* There are thirty three bits, the next bit in the sequence is bit-33 XOR |
|
* bit-20. The top 1 bit is in u1, the bottom 32 are in u0. |
|
*/ |
|
size_t i; |
|
for (i=0; i<size; ++i) |
|
{ |
|
/* First generate 8 new bits then shift them in at the end. */ |
|
png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; |
|
u1 <<= 8; |
|
u1 |= u0 >> 24; |
|
u0 <<= 8; |
|
u0 |= u; |
|
*bytes++ = (png_byte)u; |
|
} |
|
|
|
seed[0] = u0; |
|
seed[1] = u1; |
|
} |
|
|
|
static void |
|
make_four_random_bytes(png_uint_32* seed, png_bytep bytes) |
|
{ |
|
make_random_bytes(seed, bytes, 4); |
|
} |
|
|
|
#if defined PNG_READ_SUPPORTED || defined PNG_WRITE_tRNS_SUPPORTED ||\ |
|
defined PNG_WRITE_FILTER_SUPPORTED |
|
static void |
|
randomize(void *pv, size_t size) |
|
{ |
|
static png_uint_32 random_seed[2] = {0x56789abc, 0xd}; |
|
make_random_bytes(random_seed, pv, size); |
|
} |
|
|
|
#define R8(this) randomize(&(this), sizeof (this)) |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static png_byte |
|
random_byte(void) |
|
{ |
|
unsigned char b1[1]; |
|
randomize(b1, sizeof b1); |
|
return b1[0]; |
|
} |
|
#endif /* READ */ |
|
|
|
static png_uint_16 |
|
random_u16(void) |
|
{ |
|
unsigned char b2[2]; |
|
randomize(b2, sizeof b2); |
|
return png_get_uint_16(b2); |
|
} |
|
|
|
#if defined PNG_READ_RGB_TO_GRAY_SUPPORTED ||\ |
|
defined PNG_READ_FILLER_SUPPORTED |
|
static png_uint_32 |
|
random_u32(void) |
|
{ |
|
unsigned char b4[4]; |
|
randomize(b4, sizeof b4); |
|
return png_get_uint_32(b4); |
|
} |
|
#endif /* READ_FILLER || READ_RGB_TO_GRAY */ |
|
|
|
#endif /* READ || WRITE_tRNS || WRITE_FILTER */ |
|
|
|
#if defined PNG_READ_TRANSFORMS_SUPPORTED ||\ |
|
defined PNG_WRITE_FILTER_SUPPORTED |
|
static unsigned int |
|
random_mod(unsigned int max) |
|
{ |
|
return random_u16() % max; /* 0 .. max-1 */ |
|
} |
|
#endif /* READ_TRANSFORMS || WRITE_FILTER */ |
|
|
|
#if (defined PNG_READ_RGB_TO_GRAY_SUPPORTED) ||\ |
|
(defined PNG_READ_FILLER_SUPPORTED) |
|
static int |
|
random_choice(void) |
|
{ |
|
return random_byte() & 1; |
|
} |
|
#endif /* READ_RGB_TO_GRAY || READ_FILLER */ |
|
|
|
/* A numeric ID based on PNG file characteristics. The 'do_interlace' field |
|
* simply records whether pngvalid did the interlace itself or whether it |
|
* was done by libpng. Width and height must be less than 256. 'palette' is an |
|
* index of the palette to use for formats with a palette otherwise a boolean |
|
* indicating if a tRNS chunk was generated. |
|
*/ |
|
#define FILEID(col, depth, palette, interlace, width, height, do_interlace) \ |
|
((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \ |
|
(((do_interlace)!=0)<<15) + ((width)<<16) + ((height)<<24))) |
|
|
|
#define COL_FROM_ID(id) ((png_byte)((id)& 0x7U)) |
|
#define DEPTH_FROM_ID(id) ((png_byte)(((id) >> 3) & 0x1fU)) |
|
#define PALETTE_FROM_ID(id) (((id) >> 8) & 0x1f) |
|
#define INTERLACE_FROM_ID(id) ((png_byte)(((id) >> 13) & 0x3)) |
|
#define DO_INTERLACE_FROM_ID(id) ((int)(((id)>>15) & 1)) |
|
#define WIDTH_FROM_ID(id) (((id)>>16) & 0xff) |
|
#define HEIGHT_FROM_ID(id) (((id)>>24) & 0xff) |
|
|
|
/* Utility to construct a standard name for a standard image. */ |
|
static size_t |
|
standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type, |
|
int bit_depth, unsigned int npalette, int interlace_type, |
|
png_uint_32 w, png_uint_32 h, int do_interlace) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, colour_types[colour_type]); |
|
if (colour_type == 3) /* must have a palette */ |
|
{ |
|
pos = safecat(buffer, bufsize, pos, "["); |
|
pos = safecatn(buffer, bufsize, pos, npalette); |
|
pos = safecat(buffer, bufsize, pos, "]"); |
|
} |
|
|
|
else if (npalette != 0) |
|
pos = safecat(buffer, bufsize, pos, "+tRNS"); |
|
|
|
pos = safecat(buffer, bufsize, pos, " "); |
|
pos = safecatn(buffer, bufsize, pos, bit_depth); |
|
pos = safecat(buffer, bufsize, pos, " bit"); |
|
|
|
if (interlace_type != PNG_INTERLACE_NONE) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, " interlaced"); |
|
if (do_interlace) |
|
pos = safecat(buffer, bufsize, pos, "(pngvalid)"); |
|
else |
|
pos = safecat(buffer, bufsize, pos, "(libpng)"); |
|
} |
|
|
|
if (w > 0 || h > 0) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, " "); |
|
pos = safecatn(buffer, bufsize, pos, w); |
|
pos = safecat(buffer, bufsize, pos, "x"); |
|
pos = safecatn(buffer, bufsize, pos, h); |
|
} |
|
|
|
return pos; |
|
} |
|
|
|
static size_t |
|
standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id) |
|
{ |
|
return standard_name(buffer, bufsize, pos, COL_FROM_ID(id), |
|
DEPTH_FROM_ID(id), PALETTE_FROM_ID(id), INTERLACE_FROM_ID(id), |
|
WIDTH_FROM_ID(id), HEIGHT_FROM_ID(id), DO_INTERLACE_FROM_ID(id)); |
|
} |
|
|
|
/* Convenience API and defines to list valid formats. Note that 16 bit read and |
|
* write support is required to do 16 bit read tests (we must be able to make a |
|
* 16 bit image to test!) |
|
*/ |
|
#ifdef PNG_WRITE_16BIT_SUPPORTED |
|
# define WRITE_BDHI 4 |
|
# ifdef PNG_READ_16BIT_SUPPORTED |
|
# define READ_BDHI 4 |
|
# define DO_16BIT |
|
# endif |
|
#else |
|
# define WRITE_BDHI 3 |
|
#endif |
|
#ifndef DO_16BIT |
|
# define READ_BDHI 3 |
|
#endif |
|
|
|
/* The following defines the number of different palettes to generate for |
|
* each log bit depth of a colour type 3 standard image. |
|
*/ |
|
#define PALETTE_COUNT(bit_depth) ((bit_depth) > 4 ? 1U : 16U) |
|
|
|
static int |
|
next_format(png_bytep colour_type, png_bytep bit_depth, |
|
unsigned int* palette_number, int low_depth_gray, int tRNS) |
|
{ |
|
if (*bit_depth == 0) |
|
{ |
|
*colour_type = 0; |
|
if (low_depth_gray) |
|
*bit_depth = 1; |
|
else |
|
*bit_depth = 8; |
|
*palette_number = 0; |
|
return 1; |
|
} |
|
|
|
if (*colour_type < 4/*no alpha channel*/) |
|
{ |
|
/* Add multiple palettes for colour type 3, one image with tRNS |
|
* and one without for other non-alpha formats: |
|
*/ |
|
unsigned int pn = ++*palette_number; |
|
png_byte ct = *colour_type; |
|
|
|
if (((ct == 0/*GRAY*/ || ct/*RGB*/ == 2) && tRNS && pn < 2) || |
|
(ct == 3/*PALETTE*/ && pn < PALETTE_COUNT(*bit_depth))) |
|
return 1; |
|
|
|
/* No: next bit depth */ |
|
*palette_number = 0; |
|
} |
|
|
|
*bit_depth = (png_byte)(*bit_depth << 1); |
|
|
|
/* Palette images are restricted to 8 bit depth */ |
|
if (*bit_depth <= 8 |
|
#ifdef DO_16BIT |
|
|| (*colour_type != 3 && *bit_depth <= 16) |
|
#endif |
|
) |
|
return 1; |
|
|
|
/* Move to the next color type, or return 0 at the end. */ |
|
switch (*colour_type) |
|
{ |
|
case 0: |
|
*colour_type = 2; |
|
*bit_depth = 8; |
|
return 1; |
|
|
|
case 2: |
|
*colour_type = 3; |
|
*bit_depth = 1; |
|
return 1; |
|
|
|
case 3: |
|
*colour_type = 4; |
|
*bit_depth = 8; |
|
return 1; |
|
|
|
case 4: |
|
*colour_type = 6; |
|
*bit_depth = 8; |
|
return 1; |
|
|
|
default: |
|
return 0; |
|
} |
|
} |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
static unsigned int |
|
sample(png_const_bytep row, png_byte colour_type, png_byte bit_depth, |
|
png_uint_32 x, unsigned int sample_index, int swap16, int littleendian) |
|
{ |
|
png_uint_32 bit_index, result; |
|
|
|
/* Find a sample index for the desired sample: */ |
|
x *= bit_depth; |
|
bit_index = x; |
|
|
|
if ((colour_type & 1) == 0) /* !palette */ |
|
{ |
|
if (colour_type & 2) |
|
bit_index *= 3; |
|
|
|
if (colour_type & 4) |
|
bit_index += x; /* Alpha channel */ |
|
|
|
/* Multiple channels; select one: */ |
|
if (colour_type & (2+4)) |
|
bit_index += sample_index * bit_depth; |
|
} |
|
|
|
/* Return the sample from the row as an integer. */ |
|
row += bit_index >> 3; |
|
result = *row; |
|
|
|
if (bit_depth == 8) |
|
return result; |
|
|
|
else if (bit_depth > 8) |
|
{ |
|
if (swap16) |
|
return (*++row << 8) + result; |
|
else |
|
return (result << 8) + *++row; |
|
} |
|
|
|
/* Less than 8 bits per sample. By default PNG has the big end of |
|
* the egg on the left of the screen, but if littleendian is set |
|
* then the big end is on the right. |
|
*/ |
|
bit_index &= 7; |
|
|
|
if (!littleendian) |
|
bit_index = 8-bit_index-bit_depth; |
|
|
|
return (result >> bit_index) & ((1U<<bit_depth)-1); |
|
} |
|
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
|
|
/* Copy a single pixel, of a given size, from one buffer to another - |
|
* while this is basically bit addressed there is an implicit assumption |
|
* that pixels 8 or more bits in size are byte aligned and that pixels |
|
* do not otherwise cross byte boundaries. (This is, so far as I know, |
|
* universally true in bitmap computer graphics. [JCB 20101212]) |
|
* |
|
* NOTE: The to and from buffers may be the same. |
|
*/ |
|
static void |
|
pixel_copy(png_bytep toBuffer, png_uint_32 toIndex, |
|
png_const_bytep fromBuffer, png_uint_32 fromIndex, unsigned int pixelSize, |
|
int littleendian) |
|
{ |
|
/* Assume we can multiply by 'size' without overflow because we are |
|
* just working in a single buffer. |
|
*/ |
|
toIndex *= pixelSize; |
|
fromIndex *= pixelSize; |
|
if (pixelSize < 8) /* Sub-byte */ |
|
{ |
|
/* Mask to select the location of the copied pixel: */ |
|
unsigned int destMask = ((1U<<pixelSize)-1) << |
|
(littleendian ? toIndex&7 : 8-pixelSize-(toIndex&7)); |
|
/* The following read the entire pixels and clears the extra: */ |
|
unsigned int destByte = toBuffer[toIndex >> 3] & ~destMask; |
|
unsigned int sourceByte = fromBuffer[fromIndex >> 3]; |
|
|
|
/* Don't rely on << or >> supporting '0' here, just in case: */ |
|
fromIndex &= 7; |
|
if (littleendian) |
|
{ |
|
if (fromIndex > 0) sourceByte >>= fromIndex; |
|
if ((toIndex & 7) > 0) sourceByte <<= toIndex & 7; |
|
} |
|
|
|
else |
|
{ |
|
if (fromIndex > 0) sourceByte <<= fromIndex; |
|
if ((toIndex & 7) > 0) sourceByte >>= toIndex & 7; |
|
} |
|
|
|
toBuffer[toIndex >> 3] = (png_byte)(destByte | (sourceByte & destMask)); |
|
} |
|
else /* One or more bytes */ |
|
memmove(toBuffer+(toIndex>>3), fromBuffer+(fromIndex>>3), pixelSize>>3); |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
/* Copy a complete row of pixels, taking into account potential partial |
|
* bytes at the end. |
|
*/ |
|
static void |
|
row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth, |
|
int littleendian) |
|
{ |
|
memcpy(toBuffer, fromBuffer, bitWidth >> 3); |
|
|
|
if ((bitWidth & 7) != 0) |
|
{ |
|
unsigned int mask; |
|
|
|
toBuffer += bitWidth >> 3; |
|
fromBuffer += bitWidth >> 3; |
|
if (littleendian) |
|
mask = 0xff << (bitWidth & 7); |
|
else |
|
mask = 0xff >> (bitWidth & 7); |
|
*toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); |
|
} |
|
} |
|
|
|
/* Compare pixels - they are assumed to start at the first byte in the |
|
* given buffers. |
|
*/ |
|
static int |
|
pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) |
|
{ |
|
#if PNG_LIBPNG_VER < 10506 |
|
if (memcmp(pa, pb, bit_width>>3) == 0) |
|
{ |
|
png_uint_32 p; |
|
|
|
if ((bit_width & 7) == 0) return 0; |
|
|
|
/* Ok, any differences? */ |
|
p = pa[bit_width >> 3]; |
|
p ^= pb[bit_width >> 3]; |
|
|
|
if (p == 0) return 0; |
|
|
|
/* There are, but they may not be significant, remove the bits |
|
* after the end (the low order bits in PNG.) |
|
*/ |
|
bit_width &= 7; |
|
p >>= 8-bit_width; |
|
|
|
if (p == 0) return 0; |
|
} |
|
#else |
|
/* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing |
|
* bits too: |
|
*/ |
|
if (memcmp(pa, pb, (bit_width+7)>>3) == 0) |
|
return 0; |
|
#endif |
|
|
|
/* Return the index of the changed byte. */ |
|
{ |
|
png_uint_32 where = 0; |
|
|
|
while (pa[where] == pb[where]) ++where; |
|
return 1+where; |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/*************************** BASIC PNG FILE WRITING ***************************/ |
|
/* A png_store takes data from the sequential writer or provides data |
|
* to the sequential reader. It can also store the result of a PNG |
|
* write for later retrieval. |
|
*/ |
|
#define STORE_BUFFER_SIZE 500 /* arbitrary */ |
|
typedef struct png_store_buffer |
|
{ |
|
struct png_store_buffer* prev; /* NOTE: stored in reverse order */ |
|
png_byte buffer[STORE_BUFFER_SIZE]; |
|
} png_store_buffer; |
|
|
|
#define FILE_NAME_SIZE 64 |
|
|
|
typedef struct store_palette_entry /* record of a single palette entry */ |
|
{ |
|
png_byte red; |
|
png_byte green; |
|
png_byte blue; |
|
png_byte alpha; |
|
} store_palette_entry, store_palette[256]; |
|
|
|
typedef struct png_store_file |
|
{ |
|
struct png_store_file* next; /* as many as you like... */ |
|
char name[FILE_NAME_SIZE]; |
|
unsigned int IDAT_bits; /* Number of bits in IDAT size */ |
|
png_uint_32 IDAT_size; /* Total size of IDAT data */ |
|
png_uint_32 id; /* must be correct (see FILEID) */ |
|
size_t datacount; /* In this (the last) buffer */ |
|
png_store_buffer data; /* Last buffer in file */ |
|
int npalette; /* Number of entries in palette */ |
|
store_palette_entry* palette; /* May be NULL */ |
|
} png_store_file; |
|
|
|
/* The following is a pool of memory allocated by a single libpng read or write |
|
* operation. |
|
*/ |
|
typedef struct store_pool |
|
{ |
|
struct png_store *store; /* Back pointer */ |
|
struct store_memory *list; /* List of allocated memory */ |
|
png_byte mark[4]; /* Before and after data */ |
|
|
|
/* Statistics for this run. */ |
|
png_alloc_size_t max; /* Maximum single allocation */ |
|
png_alloc_size_t current; /* Current allocation */ |
|
png_alloc_size_t limit; /* Highest current allocation */ |
|
png_alloc_size_t total; /* Total allocation */ |
|
|
|
/* Overall statistics (retained across successive runs). */ |
|
png_alloc_size_t max_max; |
|
png_alloc_size_t max_limit; |
|
png_alloc_size_t max_total; |
|
} store_pool; |
|
|
|
typedef struct png_store |
|
{ |
|
/* For cexcept.h exception handling - simply store one of these; |
|
* the context is a self pointer but it may point to a different |
|
* png_store (in fact it never does in this program.) |
|
*/ |
|
struct exception_context |
|
exception_context; |
|
|
|
unsigned int verbose :1; |
|
unsigned int treat_warnings_as_errors :1; |
|
unsigned int expect_error :1; |
|
unsigned int expect_warning :1; |
|
unsigned int saw_warning :1; |
|
unsigned int speed :1; |
|
unsigned int progressive :1; /* use progressive read */ |
|
unsigned int validated :1; /* used as a temporary flag */ |
|
int nerrors; |
|
int nwarnings; |
|
int noptions; /* number of options below: */ |
|
struct { |
|
unsigned char option; /* option number, 0..30 */ |
|
unsigned char setting; /* setting (unset,invalid,on,off) */ |
|
} options[16]; |
|
char test[128]; /* Name of test */ |
|
char error[256]; |
|
|
|
/* Share fields */ |
|
png_uint_32 chunklen; /* Length of chunk+overhead (chunkpos >= 8) */ |
|
png_uint_32 chunktype;/* Type of chunk (valid if chunkpos >= 4) */ |
|
png_uint_32 chunkpos; /* Position in chunk */ |
|
png_uint_32 IDAT_size;/* Accumulated IDAT size in .new */ |
|
unsigned int IDAT_bits;/* Cache of the file store value */ |
|
|
|
/* Read fields */ |
|
png_structp pread; /* Used to read a saved file */ |
|
png_infop piread; |
|
png_store_file* current; /* Set when reading */ |
|
png_store_buffer* next; /* Set when reading */ |
|
size_t readpos; /* Position in *next */ |
|
png_byte* image; /* Buffer for reading interlaced images */ |
|
size_t cb_image; /* Size of this buffer */ |
|
size_t cb_row; /* Row size of the image(s) */ |
|
uLong IDAT_crc; |
|
png_uint_32 IDAT_len; /* Used when re-chunking IDAT chunks */ |
|
png_uint_32 IDAT_pos; /* Used when re-chunking IDAT chunks */ |
|
png_uint_32 image_h; /* Number of rows in a single image */ |
|
store_pool read_memory_pool; |
|
|
|
/* Write fields */ |
|
png_store_file* saved; |
|
png_structp pwrite; /* Used when writing a new file */ |
|
png_infop piwrite; |
|
size_t writepos; /* Position in .new */ |
|
char wname[FILE_NAME_SIZE]; |
|
png_store_buffer new; /* The end of the new PNG file being written. */ |
|
store_pool write_memory_pool; |
|
store_palette_entry* palette; |
|
int npalette; |
|
} png_store; |
|
|
|
/* Initialization and cleanup */ |
|
static void |
|
store_pool_mark(png_bytep mark) |
|
{ |
|
static png_uint_32 store_seed[2] = { 0x12345678, 1}; |
|
|
|
make_four_random_bytes(store_seed, mark); |
|
} |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
/* Use this for random 32 bit values; this function makes sure the result is |
|
* non-zero. |
|
*/ |
|
static png_uint_32 |
|
random_32(void) |
|
{ |
|
|
|
for (;;) |
|
{ |
|
png_byte mark[4]; |
|
png_uint_32 result; |
|
|
|
store_pool_mark(mark); |
|
result = png_get_uint_32(mark); |
|
|
|
if (result != 0) |
|
return result; |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
static void |
|
store_pool_init(png_store *ps, store_pool *pool) |
|
{ |
|
memset(pool, 0, sizeof *pool); |
|
|
|
pool->store = ps; |
|
pool->list = NULL; |
|
pool->max = pool->current = pool->limit = pool->total = 0; |
|
pool->max_max = pool->max_limit = pool->max_total = 0; |
|
store_pool_mark(pool->mark); |
|
} |
|
|
|
static void |
|
store_init(png_store* ps) |
|
{ |
|
memset(ps, 0, sizeof *ps); |
|
init_exception_context(&ps->exception_context); |
|
store_pool_init(ps, &ps->read_memory_pool); |
|
store_pool_init(ps, &ps->write_memory_pool); |
|
ps->verbose = 0; |
|
ps->treat_warnings_as_errors = 0; |
|
ps->expect_error = 0; |
|
ps->expect_warning = 0; |
|
ps->saw_warning = 0; |
|
ps->speed = 0; |
|
ps->progressive = 0; |
|
ps->validated = 0; |
|
ps->nerrors = ps->nwarnings = 0; |
|
ps->pread = NULL; |
|
ps->piread = NULL; |
|
ps->saved = ps->current = NULL; |
|
ps->next = NULL; |
|
ps->readpos = 0; |
|
ps->image = NULL; |
|
ps->cb_image = 0; |
|
ps->cb_row = 0; |
|
ps->image_h = 0; |
|
ps->pwrite = NULL; |
|
ps->piwrite = NULL; |
|
ps->writepos = 0; |
|
ps->chunkpos = 8; |
|
ps->chunktype = 0; |
|
ps->chunklen = 16; |
|
ps->IDAT_size = 0; |
|
ps->IDAT_bits = 0; |
|
ps->new.prev = NULL; |
|
ps->palette = NULL; |
|
ps->npalette = 0; |
|
ps->noptions = 0; |
|
} |
|
|
|
static void |
|
store_freebuffer(png_store_buffer* psb) |
|
{ |
|
if (psb->prev) |
|
{ |
|
store_freebuffer(psb->prev); |
|
free(psb->prev); |
|
psb->prev = NULL; |
|
} |
|
} |
|
|
|
static void |
|
store_freenew(png_store *ps) |
|
{ |
|
store_freebuffer(&ps->new); |
|
ps->writepos = 0; |
|
ps->chunkpos = 8; |
|
ps->chunktype = 0; |
|
ps->chunklen = 16; |
|
ps->IDAT_size = 0; |
|
ps->IDAT_bits = 0; |
|
if (ps->palette != NULL) |
|
{ |
|
free(ps->palette); |
|
ps->palette = NULL; |
|
ps->npalette = 0; |
|
} |
|
} |
|
|
|
static void |
|
store_storenew(png_store *ps) |
|
{ |
|
png_store_buffer *pb; |
|
|
|
pb = voidcast(png_store_buffer*, malloc(sizeof *pb)); |
|
|
|
if (pb == NULL) |
|
png_error(ps->pwrite, "store new: OOM"); |
|
|
|
*pb = ps->new; |
|
ps->new.prev = pb; |
|
ps->writepos = 0; |
|
} |
|
|
|
static void |
|
store_freefile(png_store_file **ppf) |
|
{ |
|
if (*ppf != NULL) |
|
{ |
|
store_freefile(&(*ppf)->next); |
|
|
|
store_freebuffer(&(*ppf)->data); |
|
(*ppf)->datacount = 0; |
|
if ((*ppf)->palette != NULL) |
|
{ |
|
free((*ppf)->palette); |
|
(*ppf)->palette = NULL; |
|
(*ppf)->npalette = 0; |
|
} |
|
free(*ppf); |
|
*ppf = NULL; |
|
} |
|
} |
|
|
|
static unsigned int |
|
bits_of(png_uint_32 num) |
|
{ |
|
/* Return the number of bits in 'num' */ |
|
unsigned int b = 0; |
|
|
|
if (num & 0xffff0000U) b += 16U, num >>= 16; |
|
if (num & 0xff00U) b += 8U, num >>= 8; |
|
if (num & 0xf0U) b += 4U, num >>= 4; |
|
if (num & 0xcU) b += 2U, num >>= 2; |
|
if (num & 0x2U) ++b, num >>= 1; |
|
if (num) ++b; |
|
|
|
return b; /* 0..32 */ |
|
} |
|
|
|
/* Main interface to file storage, after writing a new PNG file (see the API |
|
* below) call store_storefile to store the result with the given name and id. |
|
*/ |
|
static void |
|
store_storefile(png_store *ps, png_uint_32 id) |
|
{ |
|
png_store_file *pf; |
|
|
|
if (ps->chunkpos != 0U || ps->chunktype != 0U || ps->chunklen != 0U || |
|
ps->IDAT_size == 0) |
|
png_error(ps->pwrite, "storefile: incomplete write"); |
|
|
|
pf = voidcast(png_store_file*, malloc(sizeof *pf)); |
|
if (pf == NULL) |
|
png_error(ps->pwrite, "storefile: OOM"); |
|
safecat(pf->name, sizeof pf->name, 0, ps->wname); |
|
pf->id = id; |
|
pf->data = ps->new; |
|
pf->datacount = ps->writepos; |
|
pf->IDAT_size = ps->IDAT_size; |
|
pf->IDAT_bits = bits_of(ps->IDAT_size); |
|
/* Because the IDAT always has zlib header stuff this must be true: */ |
|
if (pf->IDAT_bits == 0U) |
|
png_error(ps->pwrite, "storefile: 0 sized IDAT"); |
|
ps->new.prev = NULL; |
|
ps->writepos = 0; |
|
ps->chunkpos = 8; |
|
ps->chunktype = 0; |
|
ps->chunklen = 16; |
|
ps->IDAT_size = 0; |
|
pf->palette = ps->palette; |
|
pf->npalette = ps->npalette; |
|
ps->palette = 0; |
|
ps->npalette = 0; |
|
|
|
/* And save it. */ |
|
pf->next = ps->saved; |
|
ps->saved = pf; |
|
} |
|
|
|
/* Generate an error message (in the given buffer) */ |
|
static size_t |
|
store_message(png_store *ps, png_const_structp pp, char *buffer, size_t bufsize, |
|
size_t pos, const char *msg) |
|
{ |
|
if (pp != NULL && pp == ps->pread) |
|
{ |
|
/* Reading a file */ |
|
pos = safecat(buffer, bufsize, pos, "read: "); |
|
|
|
if (ps->current != NULL) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, ps->current->name); |
|
pos = safecat(buffer, bufsize, pos, sep); |
|
} |
|
} |
|
|
|
else if (pp != NULL && pp == ps->pwrite) |
|
{ |
|
/* Writing a file */ |
|
pos = safecat(buffer, bufsize, pos, "write: "); |
|
pos = safecat(buffer, bufsize, pos, ps->wname); |
|
pos = safecat(buffer, bufsize, pos, sep); |
|
} |
|
|
|
else |
|
{ |
|
/* Neither reading nor writing (or a memory error in struct delete) */ |
|
pos = safecat(buffer, bufsize, pos, "pngvalid: "); |
|
} |
|
|
|
if (ps->test[0] != 0) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, ps->test); |
|
pos = safecat(buffer, bufsize, pos, sep); |
|
} |
|
pos = safecat(buffer, bufsize, pos, msg); |
|
return pos; |
|
} |
|
|
|
/* Verbose output to the error stream: */ |
|
static void |
|
store_verbose(png_store *ps, png_const_structp pp, png_const_charp prefix, |
|
png_const_charp message) |
|
{ |
|
char buffer[512]; |
|
|
|
if (prefix) |
|
fputs(prefix, stderr); |
|
|
|
(void)store_message(ps, pp, buffer, sizeof buffer, 0, message); |
|
fputs(buffer, stderr); |
|
fputc('\n', stderr); |
|
} |
|
|
|
/* Log an error or warning - the relevant count is always incremented. */ |
|
static void |
|
store_log(png_store* ps, png_const_structp pp, png_const_charp message, |
|
int is_error) |
|
{ |
|
/* The warning is copied to the error buffer if there are no errors and it is |
|
* the first warning. The error is copied to the error buffer if it is the |
|
* first error (overwriting any prior warnings). |
|
*/ |
|
if (is_error ? (ps->nerrors)++ == 0 : |
|
(ps->nwarnings)++ == 0 && ps->nerrors == 0) |
|
store_message(ps, pp, ps->error, sizeof ps->error, 0, message); |
|
|
|
if (ps->verbose) |
|
store_verbose(ps, pp, is_error ? "error: " : "warning: ", message); |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
/* Internal error function, called with a png_store but no libpng stuff. */ |
|
static void |
|
internal_error(png_store *ps, png_const_charp message) |
|
{ |
|
store_log(ps, NULL, message, 1 /* error */); |
|
|
|
/* And finally throw an exception. */ |
|
{ |
|
struct exception_context *the_exception_context = &ps->exception_context; |
|
Throw ps; |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* Functions to use as PNG callbacks. */ |
|
static void PNGCBAPI |
|
store_error(png_structp ppIn, png_const_charp message) /* PNG_NORETURN */ |
|
{ |
|
png_const_structp pp = ppIn; |
|
png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); |
|
|
|
if (!ps->expect_error) |
|
store_log(ps, pp, message, 1 /* error */); |
|
|
|
/* And finally throw an exception. */ |
|
{ |
|
struct exception_context *the_exception_context = &ps->exception_context; |
|
Throw ps; |
|
} |
|
} |
|
|
|
static void PNGCBAPI |
|
store_warning(png_structp ppIn, png_const_charp message) |
|
{ |
|
png_const_structp pp = ppIn; |
|
png_store *ps = voidcast(png_store*, png_get_error_ptr(pp)); |
|
|
|
if (!ps->expect_warning) |
|
store_log(ps, pp, message, 0 /* warning */); |
|
else |
|
ps->saw_warning = 1; |
|
} |
|
|
|
/* These somewhat odd functions are used when reading an image to ensure that |
|
* the buffer is big enough, the png_structp is for errors. |
|
*/ |
|
/* Return a single row from the correct image. */ |
|
static png_bytep |
|
store_image_row(const png_store* ps, png_const_structp pp, int nImage, |
|
png_uint_32 y) |
|
{ |
|
size_t coffset = (nImage * ps->image_h + y) * (ps->cb_row + 5) + 2; |
|
|
|
if (ps->image == NULL) |
|
png_error(pp, "no allocated image"); |
|
|
|
if (coffset + ps->cb_row + 3 > ps->cb_image) |
|
png_error(pp, "image too small"); |
|
|
|
return ps->image + coffset; |
|
} |
|
|
|
static void |
|
store_image_free(png_store *ps, png_const_structp pp) |
|
{ |
|
if (ps->image != NULL) |
|
{ |
|
png_bytep image = ps->image; |
|
|
|
if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) |
|
{ |
|
if (pp != NULL) |
|
png_error(pp, "png_store image overwrite (1)"); |
|
else |
|
store_log(ps, NULL, "png_store image overwrite (2)", 1); |
|
} |
|
|
|
ps->image = NULL; |
|
ps->cb_image = 0; |
|
--image; |
|
free(image); |
|
} |
|
} |
|
|
|
static void |
|
store_ensure_image(png_store *ps, png_const_structp pp, int nImages, |
|
size_t cbRow, png_uint_32 cRows) |
|
{ |
|
size_t cb = nImages * cRows * (cbRow + 5); |
|
|
|
if (ps->cb_image < cb) |
|
{ |
|
png_bytep image; |
|
|
|
store_image_free(ps, pp); |
|
|
|
/* The buffer is deliberately mis-aligned. */ |
|
image = voidcast(png_bytep, malloc(cb+2)); |
|
if (image == NULL) |
|
{ |
|
/* Called from the startup - ignore the error for the moment. */ |
|
if (pp == NULL) |
|
return; |
|
|
|
png_error(pp, "OOM allocating image buffer"); |
|
} |
|
|
|
/* These magic tags are used to detect overwrites above. */ |
|
++image; |
|
image[-1] = 0xed; |
|
image[cb] = 0xfe; |
|
|
|
ps->image = image; |
|
ps->cb_image = cb; |
|
} |
|
|
|
/* We have an adequate sized image; lay out the rows. There are 2 bytes at |
|
* the start and three at the end of each (this ensures that the row |
|
* alignment starts out odd - 2+1 and changes for larger images on each row.) |
|
*/ |
|
ps->cb_row = cbRow; |
|
ps->image_h = cRows; |
|
|
|
/* For error checking, the whole buffer is set to 10110010 (0xb2 - 178). |
|
* This deliberately doesn't match the bits in the size test image which are |
|
* outside the image; these are set to 0xff (all 1). To make the row |
|
* comparison work in the 'size' test case the size rows are pre-initialized |
|
* to the same value prior to calling 'standard_row'. |
|
*/ |
|
memset(ps->image, 178, cb); |
|
|
|
/* Then put in the marks. */ |
|
while (--nImages >= 0) |
|
{ |
|
png_uint_32 y; |
|
|
|
for (y=0; y<cRows; ++y) |
|
{ |
|
png_bytep row = store_image_row(ps, pp, nImages, y); |
|
|
|
/* The markers: */ |
|
row[-2] = 190; |
|
row[-1] = 239; |
|
row[cbRow] = 222; |
|
row[cbRow+1] = 173; |
|
row[cbRow+2] = 17; |
|
} |
|
} |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static void |
|
store_image_check(const png_store* ps, png_const_structp pp, int iImage) |
|
{ |
|
png_const_bytep image = ps->image; |
|
|
|
if (image[-1] != 0xed || image[ps->cb_image] != 0xfe) |
|
png_error(pp, "image overwrite"); |
|
else |
|
{ |
|
size_t cbRow = ps->cb_row; |
|
png_uint_32 rows = ps->image_h; |
|
|
|
image += iImage * (cbRow+5) * ps->image_h; |
|
|
|
image += 2; /* skip image first row markers */ |
|
|
|
for (; rows > 0; --rows) |
|
{ |
|
if (image[-2] != 190 || image[-1] != 239) |
|
png_error(pp, "row start overwritten"); |
|
|
|
if (image[cbRow] != 222 || image[cbRow+1] != 173 || |
|
image[cbRow+2] != 17) |
|
png_error(pp, "row end overwritten"); |
|
|
|
image += cbRow+5; |
|
} |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
static int |
|
valid_chunktype(png_uint_32 chunktype) |
|
{ |
|
/* Each byte in the chunk type must be in one of the ranges 65..90, 97..122 |
|
* (both inclusive), so: |
|
*/ |
|
unsigned int i; |
|
|
|
for (i=0; i<4; ++i) |
|
{ |
|
unsigned int c = chunktype & 0xffU; |
|
|
|
if (!((c >= 65U && c <= 90U) || (c >= 97U && c <= 122U))) |
|
return 0; |
|
|
|
chunktype >>= 8; |
|
} |
|
|
|
return 1; /* It's valid */ |
|
} |
|
|
|
static void PNGCBAPI |
|
store_write(png_structp ppIn, png_bytep pb, size_t st) |
|
{ |
|
png_const_structp pp = ppIn; |
|
png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); |
|
size_t writepos = ps->writepos; |
|
png_uint_32 chunkpos = ps->chunkpos; |
|
png_uint_32 chunktype = ps->chunktype; |
|
png_uint_32 chunklen = ps->chunklen; |
|
|
|
if (ps->pwrite != pp) |
|
png_error(pp, "store state damaged"); |
|
|
|
/* Technically this is legal, but in practice libpng never writes more than |
|
* the maximum chunk size at once so if it happens something weird has |
|
* changed inside libpng (probably). |
|
*/ |
|
if (st > 0x7fffffffU) |
|
png_error(pp, "unexpected write size"); |
|
|
|
/* Now process the bytes to be written. Do this in units of the space in the |
|
* output (write) buffer or, at the start 4 bytes for the chunk type and |
|
* length limited in any case by the amount of data. |
|
*/ |
|
while (st > 0) |
|
{ |
|
if (writepos >= STORE_BUFFER_SIZE) |
|
store_storenew(ps), writepos = 0; |
|
|
|
if (chunkpos < 4) |
|
{ |
|
png_byte b = *pb++; |
|
--st; |
|
chunklen = (chunklen << 8) + b; |
|
ps->new.buffer[writepos++] = b; |
|
++chunkpos; |
|
} |
|
|
|
else if (chunkpos < 8) |
|
{ |
|
png_byte b = *pb++; |
|
--st; |
|
chunktype = (chunktype << 8) + b; |
|
ps->new.buffer[writepos++] = b; |
|
|
|
if (++chunkpos == 8) |
|
{ |
|
chunklen &= 0xffffffffU; |
|
if (chunklen > 0x7fffffffU) |
|
png_error(pp, "chunk length too great"); |
|
|
|
chunktype &= 0xffffffffU; |
|
if (chunktype == CHUNK_IDAT) |
|
{ |
|
if (chunklen > ~ps->IDAT_size) |
|
png_error(pp, "pngvalid internal image too large"); |
|
|
|
ps->IDAT_size += chunklen; |
|
} |
|
|
|
else if (!valid_chunktype(chunktype)) |
|
png_error(pp, "invalid chunk type"); |
|
|
|
chunklen += 12; /* for header and CRC */ |
|
} |
|
} |
|
|
|
else /* chunkpos >= 8 */ |
|
{ |
|
size_t cb = st; |
|
|
|
if (cb > STORE_BUFFER_SIZE - writepos) |
|
cb = STORE_BUFFER_SIZE - writepos; |
|
|
|
if (cb > chunklen - chunkpos/* bytes left in chunk*/) |
|
cb = (size_t)/*SAFE*/(chunklen - chunkpos); |
|
|
|
memcpy(ps->new.buffer + writepos, pb, cb); |
|
chunkpos += (png_uint_32)/*SAFE*/cb; |
|
pb += cb; |
|
writepos += cb; |
|
st -= cb; |
|
|
|
if (chunkpos >= chunklen) /* must be equal */ |
|
chunkpos = chunktype = chunklen = 0; |
|
} |
|
} /* while (st > 0) */ |
|
|
|
ps->writepos = writepos; |
|
ps->chunkpos = chunkpos; |
|
ps->chunktype = chunktype; |
|
ps->chunklen = chunklen; |
|
} |
|
|
|
static void PNGCBAPI |
|
store_flush(png_structp ppIn) |
|
{ |
|
UNUSED(ppIn) /*DOES NOTHING*/ |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static size_t |
|
store_read_buffer_size(png_store *ps) |
|
{ |
|
/* Return the bytes available for read in the current buffer. */ |
|
if (ps->next != &ps->current->data) |
|
return STORE_BUFFER_SIZE; |
|
|
|
return ps->current->datacount; |
|
} |
|
|
|
/* Return total bytes available for read. */ |
|
static size_t |
|
store_read_buffer_avail(png_store *ps) |
|
{ |
|
if (ps->current != NULL && ps->next != NULL) |
|
{ |
|
png_store_buffer *next = &ps->current->data; |
|
size_t cbAvail = ps->current->datacount; |
|
|
|
while (next != ps->next && next != NULL) |
|
{ |
|
next = next->prev; |
|
cbAvail += STORE_BUFFER_SIZE; |
|
} |
|
|
|
if (next != ps->next) |
|
png_error(ps->pread, "buffer read error"); |
|
|
|
if (cbAvail > ps->readpos) |
|
return cbAvail - ps->readpos; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
store_read_buffer_next(png_store *ps) |
|
{ |
|
png_store_buffer *pbOld = ps->next; |
|
png_store_buffer *pbNew = &ps->current->data; |
|
if (pbOld != pbNew) |
|
{ |
|
while (pbNew != NULL && pbNew->prev != pbOld) |
|
pbNew = pbNew->prev; |
|
|
|
if (pbNew != NULL) |
|
{ |
|
ps->next = pbNew; |
|
ps->readpos = 0; |
|
return 1; |
|
} |
|
|
|
png_error(ps->pread, "buffer lost"); |
|
} |
|
|
|
return 0; /* EOF or error */ |
|
} |
|
|
|
/* Need separate implementation and callback to allow use of the same code |
|
* during progressive read, where the io_ptr is set internally by libpng. |
|
*/ |
|
static void |
|
store_read_imp(png_store *ps, png_bytep pb, size_t st) |
|
{ |
|
if (ps->current == NULL || ps->next == NULL) |
|
png_error(ps->pread, "store state damaged"); |
|
|
|
while (st > 0) |
|
{ |
|
size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; |
|
|
|
if (cbAvail > 0) |
|
{ |
|
if (cbAvail > st) cbAvail = st; |
|
memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); |
|
st -= cbAvail; |
|
pb += cbAvail; |
|
ps->readpos += cbAvail; |
|
} |
|
|
|
else if (!store_read_buffer_next(ps)) |
|
png_error(ps->pread, "read beyond end of file"); |
|
} |
|
} |
|
|
|
static size_t |
|
store_read_chunk(png_store *ps, png_bytep pb, size_t max, size_t min) |
|
{ |
|
png_uint_32 chunklen = ps->chunklen; |
|
png_uint_32 chunktype = ps->chunktype; |
|
png_uint_32 chunkpos = ps->chunkpos; |
|
size_t st = max; |
|
|
|
if (st > 0) do |
|
{ |
|
if (chunkpos >= chunklen) /* end of last chunk */ |
|
{ |
|
png_byte buffer[8]; |
|
|
|
/* Read the header of the next chunk: */ |
|
store_read_imp(ps, buffer, 8U); |
|
chunklen = png_get_uint_32(buffer) + 12U; |
|
chunktype = png_get_uint_32(buffer+4U); |
|
chunkpos = 0U; /* Position read so far */ |
|
} |
|
|
|
if (chunktype == CHUNK_IDAT) |
|
{ |
|
png_uint_32 IDAT_pos = ps->IDAT_pos; |
|
png_uint_32 IDAT_len = ps->IDAT_len; |
|
png_uint_32 IDAT_size = ps->IDAT_size; |
|
|
|
/* The IDAT headers are constructed here; skip the input header. */ |
|
if (chunkpos < 8U) |
|
chunkpos = 8U; |
|
|
|
if (IDAT_pos == IDAT_len) |
|
{ |
|
png_byte random = random_byte(); |
|
|
|
/* Make a new IDAT chunk, if IDAT_len is 0 this is the first IDAT, |
|
* if IDAT_size is 0 this is the end. At present this is set up |
|
* using a random number so that there is a 25% chance before |
|
* the start of the first IDAT chunk being 0 length. |
|
*/ |
|
if (IDAT_len == 0U) /* First IDAT */ |
|
{ |
|
switch (random & 3U) |
|
{ |
|
case 0U: IDAT_len = 12U; break; /* 0 bytes */ |
|
case 1U: IDAT_len = 13U; break; /* 1 byte */ |
|
default: IDAT_len = random_u32(); |
|
IDAT_len %= IDAT_size; |
|
IDAT_len += 13U; /* 1..IDAT_size bytes */ |
|
break; |
|
} |
|
} |
|
|
|
else if (IDAT_size == 0U) /* all IDAT data read */ |
|
{ |
|
/* The last (IDAT) chunk should be positioned at the CRC now: */ |
|
if (chunkpos != chunklen-4U) |
|
png_error(ps->pread, "internal: IDAT size mismatch"); |
|
|
|
/* The only option here is to add a zero length IDAT, this |
|
* happens 25% of the time. Because of the check above |
|
* chunklen-4U-chunkpos must be zero, we just need to skip the |
|
* CRC now. |
|
*/ |
|
if ((random & 3U) == 0U) |
|
IDAT_len = 12U; /* Output another 0 length IDAT */ |
|
|
|
else |
|
{ |
|
/* End of IDATs, skip the CRC to make the code above load the |
|
* next chunk header next time round. |
|
*/ |
|
png_byte buffer[4]; |
|
|
|
store_read_imp(ps, buffer, 4U); |
|
chunkpos += 4U; |
|
ps->IDAT_pos = IDAT_pos; |
|
ps->IDAT_len = IDAT_len; |
|
ps->IDAT_size = 0U; |
|
continue; /* Read the next chunk */ |
|
} |
|
} |
|
|
|
else |
|
{ |
|
/* Middle of IDATs, use 'random' to determine the number of bits |
|
* to use in the IDAT length. |
|
*/ |
|
IDAT_len = random_u32(); |
|
IDAT_len &= (1U << (1U + random % ps->IDAT_bits)) - 1U; |
|
if (IDAT_len > IDAT_size) |
|
IDAT_len = IDAT_size; |
|
IDAT_len += 12U; /* zero bytes may occur */ |
|
} |
|
|
|
IDAT_pos = 0U; |
|
ps->IDAT_crc = 0x35af061e; /* Ie: crc32(0UL, "IDAT", 4) */ |
|
} /* IDAT_pos == IDAT_len */ |
|
|
|
if (IDAT_pos < 8U) /* Return the header */ do |
|
{ |
|
png_uint_32 b; |
|
unsigned int shift; |
|
|
|
if (IDAT_pos < 4U) |
|
b = IDAT_len - 12U; |
|
|
|
else |
|
b = CHUNK_IDAT; |
|
|
|
shift = 3U & IDAT_pos; |
|
++IDAT_pos; |
|
|
|
if (shift < 3U) |
|
b >>= 8U*(3U-shift); |
|
|
|
*pb++ = 0xffU & b; |
|
} |
|
while (--st > 0 && IDAT_pos < 8); |
|
|
|
else if (IDAT_pos < IDAT_len - 4U) /* I.e not the CRC */ |
|
{ |
|
if (chunkpos < chunklen-4U) |
|
{ |
|
uInt avail = (uInt)-1; |
|
|
|
if (avail > (IDAT_len-4U) - IDAT_pos) |
|
avail = (uInt)/*SAFE*/((IDAT_len-4U) - IDAT_pos); |
|
|
|
if (avail > st) |
|
avail = (uInt)/*SAFE*/st; |
|
|
|
if (avail > (chunklen-4U) - chunkpos) |
|
avail = (uInt)/*SAFE*/((chunklen-4U) - chunkpos); |
|
|
|
store_read_imp(ps, pb, avail); |
|
ps->IDAT_crc = crc32(ps->IDAT_crc, pb, avail); |
|
pb += (size_t)/*SAFE*/avail; |
|
st -= (size_t)/*SAFE*/avail; |
|
chunkpos += (png_uint_32)/*SAFE*/avail; |
|
IDAT_size -= (png_uint_32)/*SAFE*/avail; |
|
IDAT_pos += (png_uint_32)/*SAFE*/avail; |
|
} |
|
|
|
else /* skip the input CRC */ |
|
{ |
|
png_byte buffer[4]; |
|
|
|
store_read_imp(ps, buffer, 4U); |
|
chunkpos += 4U; |
|
} |
|
} |
|
|
|
else /* IDAT crc */ do |
|
{ |
|
uLong b = ps->IDAT_crc; |
|
unsigned int shift = (IDAT_len - IDAT_pos); /* 4..1 */ |
|
++IDAT_pos; |
|
|
|
if (shift > 1U) |
|
b >>= 8U*(shift-1U); |
|
|
|
*pb++ = 0xffU & b; |
|
} |
|
while (--st > 0 && IDAT_pos < IDAT_len); |
|
|
|
ps->IDAT_pos = IDAT_pos; |
|
ps->IDAT_len = IDAT_len; |
|
ps->IDAT_size = IDAT_size; |
|
} |
|
|
|
else /* !IDAT */ |
|
{ |
|
/* If there is still some pending IDAT data after the IDAT chunks have |
|
* been processed there is a problem: |
|
*/ |
|
if (ps->IDAT_len > 0 && ps->IDAT_size > 0) |
|
png_error(ps->pread, "internal: missing IDAT data"); |
|
|
|
if (chunktype == CHUNK_IEND && ps->IDAT_len == 0U) |
|
png_error(ps->pread, "internal: missing IDAT"); |
|
|
|
if (chunkpos < 8U) /* Return the header */ do |
|
{ |
|
png_uint_32 b; |
|
unsigned int shift; |
|
|
|
if (chunkpos < 4U) |
|
b = chunklen - 12U; |
|
|
|
else |
|
b = chunktype; |
|
|
|
shift = 3U & chunkpos; |
|
++chunkpos; |
|
|
|
if (shift < 3U) |
|
b >>= 8U*(3U-shift); |
|
|
|
*pb++ = 0xffU & b; |
|
} |
|
while (--st > 0 && chunkpos < 8); |
|
|
|
else /* Return chunk bytes, including the CRC */ |
|
{ |
|
size_t avail = st; |
|
|
|
if (avail > chunklen - chunkpos) |
|
avail = (size_t)/*SAFE*/(chunklen - chunkpos); |
|
|
|
store_read_imp(ps, pb, avail); |
|
pb += avail; |
|
st -= avail; |
|
chunkpos += (png_uint_32)/*SAFE*/avail; |
|
|
|
/* Check for end of chunk and end-of-file; don't try to read a new |
|
* chunk header at this point unless instructed to do so by 'min'. |
|
*/ |
|
if (chunkpos >= chunklen && max-st >= min && |
|
store_read_buffer_avail(ps) == 0) |
|
break; |
|
} |
|
} /* !IDAT */ |
|
} |
|
while (st > 0); |
|
|
|
ps->chunklen = chunklen; |
|
ps->chunktype = chunktype; |
|
ps->chunkpos = chunkpos; |
|
|
|
return st; /* space left */ |
|
} |
|
|
|
static void PNGCBAPI |
|
store_read(png_structp ppIn, png_bytep pb, size_t st) |
|
{ |
|
png_const_structp pp = ppIn; |
|
png_store *ps = voidcast(png_store*, png_get_io_ptr(pp)); |
|
|
|
if (ps == NULL || ps->pread != pp) |
|
png_error(pp, "bad store read call"); |
|
|
|
store_read_chunk(ps, pb, st, st); |
|
} |
|
|
|
static void |
|
store_progressive_read(png_store *ps, png_structp pp, png_infop pi) |
|
{ |
|
if (ps->pread != pp || ps->current == NULL || ps->next == NULL) |
|
png_error(pp, "store state damaged (progressive)"); |
|
|
|
/* This is another Horowitz and Hill random noise generator. In this case |
|
* the aim is to stress the progressive reader with truly horrible variable |
|
* buffer sizes in the range 1..500, so a sequence of 9 bit random numbers |
|
* is generated. We could probably just count from 1 to 32767 and get as |
|
* good a result. |
|
*/ |
|
while (store_read_buffer_avail(ps) > 0) |
|
{ |
|
static png_uint_32 noise = 2; |
|
size_t cb; |
|
png_byte buffer[512]; |
|
|
|
/* Generate 15 more bits of stuff: */ |
|
noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); |
|
cb = noise & 0x1ff; |
|
cb -= store_read_chunk(ps, buffer, cb, 1); |
|
png_process_data(pp, pi, buffer, cb); |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* The caller must fill this in: */ |
|
static store_palette_entry * |
|
store_write_palette(png_store *ps, int npalette) |
|
{ |
|
if (ps->pwrite == NULL) |
|
store_log(ps, NULL, "attempt to write palette without write stream", 1); |
|
|
|
if (ps->palette != NULL) |
|
png_error(ps->pwrite, "multiple store_write_palette calls"); |
|
|
|
/* This function can only return NULL if called with '0'! */ |
|
if (npalette > 0) |
|
{ |
|
ps->palette = voidcast(store_palette_entry*, malloc(npalette * |
|
sizeof *ps->palette)); |
|
|
|
if (ps->palette == NULL) |
|
png_error(ps->pwrite, "store new palette: OOM"); |
|
|
|
ps->npalette = npalette; |
|
} |
|
|
|
return ps->palette; |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static store_palette_entry * |
|
store_current_palette(png_store *ps, int *npalette) |
|
{ |
|
/* This is an internal error (the call has been made outside a read |
|
* operation.) |
|
*/ |
|
if (ps->current == NULL) |
|
{ |
|
store_log(ps, ps->pread, "no current stream for palette", 1); |
|
return NULL; |
|
} |
|
|
|
/* The result may be null if there is no palette. */ |
|
*npalette = ps->current->npalette; |
|
return ps->current->palette; |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/***************************** MEMORY MANAGEMENT*** ***************************/ |
|
#ifdef PNG_USER_MEM_SUPPORTED |
|
/* A store_memory is simply the header for an allocated block of memory. The |
|
* pointer returned to libpng is just after the end of the header block, the |
|
* allocated memory is followed by a second copy of the 'mark'. |
|
*/ |
|
typedef struct store_memory |
|
{ |
|
store_pool *pool; /* Originating pool */ |
|
struct store_memory *next; /* Singly linked list */ |
|
png_alloc_size_t size; /* Size of memory allocated */ |
|
png_byte mark[4]; /* ID marker */ |
|
} store_memory; |
|
|
|
/* Handle a fatal error in memory allocation. This calls png_error if the |
|
* libpng struct is non-NULL, else it outputs a message and returns. This means |
|
* that a memory problem while libpng is running will abort (png_error) the |
|
* handling of particular file while one in cleanup (after the destroy of the |
|
* struct has returned) will simply keep going and free (or attempt to free) |
|
* all the memory. |
|
*/ |
|
static void |
|
store_pool_error(png_store *ps, png_const_structp pp, const char *msg) |
|
{ |
|
if (pp != NULL) |
|
png_error(pp, msg); |
|
|
|
/* Else we have to do it ourselves. png_error eventually calls store_log, |
|
* above. store_log accepts a NULL png_structp - it just changes what gets |
|
* output by store_message. |
|
*/ |
|
store_log(ps, pp, msg, 1 /* error */); |
|
} |
|
|
|
static void |
|
store_memory_free(png_const_structp pp, store_pool *pool, store_memory *memory) |
|
{ |
|
/* Note that pp may be NULL (see store_pool_delete below), the caller has |
|
* found 'memory' in pool->list *and* unlinked this entry, so this is a valid |
|
* pointer (for sure), but the contents may have been trashed. |
|
*/ |
|
if (memory->pool != pool) |
|
store_pool_error(pool->store, pp, "memory corrupted (pool)"); |
|
|
|
else if (memcmp(memory->mark, pool->mark, sizeof memory->mark) != 0) |
|
store_pool_error(pool->store, pp, "memory corrupted (start)"); |
|
|
|
/* It should be safe to read the size field now. */ |
|
else |
|
{ |
|
png_alloc_size_t cb = memory->size; |
|
|
|
if (cb > pool->max) |
|
store_pool_error(pool->store, pp, "memory corrupted (size)"); |
|
|
|
else if (memcmp((png_bytep)(memory+1)+cb, pool->mark, sizeof pool->mark) |
|
!= 0) |
|
store_pool_error(pool->store, pp, "memory corrupted (end)"); |
|
|
|
/* Finally give the library a chance to find problems too: */ |
|
else |
|
{ |
|
pool->current -= cb; |
|
free(memory); |
|
} |
|
} |
|
} |
|
|
|
static void |
|
store_pool_delete(png_store *ps, store_pool *pool) |
|
{ |
|
if (pool->list != NULL) |
|
{ |
|
fprintf(stderr, "%s: %s %s: memory lost (list follows):\n", ps->test, |
|
pool == &ps->read_memory_pool ? "read" : "write", |
|
pool == &ps->read_memory_pool ? (ps->current != NULL ? |
|
ps->current->name : "unknown file") : ps->wname); |
|
++ps->nerrors; |
|
|
|
do |
|
{ |
|
store_memory *next = pool->list; |
|
pool->list = next->next; |
|
next->next = NULL; |
|
|
|
fprintf(stderr, "\t%lu bytes @ %p\n", |
|
(unsigned long)next->size, (const void*)(next+1)); |
|
/* The NULL means this will always return, even if the memory is |
|
* corrupted. |
|
*/ |
|
store_memory_free(NULL, pool, next); |
|
} |
|
while (pool->list != NULL); |
|
} |
|
|
|
/* And reset the other fields too for the next time. */ |
|
if (pool->max > pool->max_max) pool->max_max = pool->max; |
|
pool->max = 0; |
|
if (pool->current != 0) /* unexpected internal error */ |
|
fprintf(stderr, "%s: %s %s: memory counter mismatch (internal error)\n", |
|
ps->test, pool == &ps->read_memory_pool ? "read" : "write", |
|
pool == &ps->read_memory_pool ? (ps->current != NULL ? |
|
ps->current->name : "unknown file") : ps->wname); |
|
pool->current = 0; |
|
|
|
if (pool->limit > pool->max_limit) |
|
pool->max_limit = pool->limit; |
|
|
|
pool->limit = 0; |
|
|
|
if (pool->total > pool->max_total) |
|
pool->max_total = pool->total; |
|
|
|
pool->total = 0; |
|
|
|
/* Get a new mark too. */ |
|
store_pool_mark(pool->mark); |
|
} |
|
|
|
/* The memory callbacks: */ |
|
static png_voidp PNGCBAPI |
|
store_malloc(png_structp ppIn, png_alloc_size_t cb) |
|
{ |
|
png_const_structp pp = ppIn; |
|
store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); |
|
store_memory *new = voidcast(store_memory*, malloc(cb + (sizeof *new) + |
|
(sizeof pool->mark))); |
|
|
|
if (new != NULL) |
|
{ |
|
if (cb > pool->max) |
|
pool->max = cb; |
|
|
|
pool->current += cb; |
|
|
|
if (pool->current > pool->limit) |
|
pool->limit = pool->current; |
|
|
|
pool->total += cb; |
|
|
|
new->size = cb; |
|
memcpy(new->mark, pool->mark, sizeof new->mark); |
|
memcpy((png_byte*)(new+1) + cb, pool->mark, sizeof pool->mark); |
|
new->pool = pool; |
|
new->next = pool->list; |
|
pool->list = new; |
|
++new; |
|
} |
|
|
|
else |
|
{ |
|
/* NOTE: the PNG user malloc function cannot use the png_ptr it is passed |
|
* other than to retrieve the allocation pointer! libpng calls the |
|
* store_malloc callback in two basic cases: |
|
* |
|
* 1) From png_malloc; png_malloc will do a png_error itself if NULL is |
|
* returned. |
|
* 2) From png_struct or png_info structure creation; png_malloc is |
|
* to return so cleanup can be performed. |
|
* |
|
* To handle this store_malloc can log a message, but can't do anything |
|
* else. |
|
*/ |
|
store_log(pool->store, pp, "out of memory", 1 /* is_error */); |
|
} |
|
|
|
return new; |
|
} |
|
|
|
static void PNGCBAPI |
|
store_free(png_structp ppIn, png_voidp memory) |
|
{ |
|
png_const_structp pp = ppIn; |
|
store_pool *pool = voidcast(store_pool*, png_get_mem_ptr(pp)); |
|
store_memory *this = voidcast(store_memory*, memory), **test; |
|
|
|
/* Because libpng calls store_free with a dummy png_struct when deleting |
|
* png_struct or png_info via png_destroy_struct_2 it is necessary to check |
|
* the passed in png_structp to ensure it is valid, and not pass it to |
|
* png_error if it is not. |
|
*/ |
|
if (pp != pool->store->pread && pp != pool->store->pwrite) |
|
pp = NULL; |
|
|
|
/* First check that this 'memory' really is valid memory - it must be in the |
|
* pool list. If it is, use the shared memory_free function to free it. |
|
*/ |
|
--this; |
|
for (test = &pool->list; *test != this; test = &(*test)->next) |
|
{ |
|
if (*test == NULL) |
|
{ |
|
store_pool_error(pool->store, pp, "bad pointer to free"); |
|
return; |
|
} |
|
} |
|
|
|
/* Unlink this entry, *test == this. */ |
|
*test = this->next; |
|
this->next = NULL; |
|
store_memory_free(pp, pool, this); |
|
} |
|
#endif /* PNG_USER_MEM_SUPPORTED */ |
|
|
|
/* Setup functions. */ |
|
/* Cleanup when aborting a write or after storing the new file. */ |
|
static void |
|
store_write_reset(png_store *ps) |
|
{ |
|
if (ps->pwrite != NULL) |
|
{ |
|
anon_context(ps); |
|
|
|
Try |
|
png_destroy_write_struct(&ps->pwrite, &ps->piwrite); |
|
|
|
Catch_anonymous |
|
{ |
|
/* memory corruption: continue. */ |
|
} |
|
|
|
ps->pwrite = NULL; |
|
ps->piwrite = NULL; |
|
} |
|
|
|
/* And make sure that all the memory has been freed - this will output |
|
* spurious errors in the case of memory corruption above, but this is safe. |
|
*/ |
|
# ifdef PNG_USER_MEM_SUPPORTED |
|
store_pool_delete(ps, &ps->write_memory_pool); |
|
# endif |
|
|
|
store_freenew(ps); |
|
} |
|
|
|
/* The following is the main write function, it returns a png_struct and, |
|
* optionally, a png_info suitable for writiing a new PNG file. Use |
|
* store_storefile above to record this file after it has been written. The |
|
* returned libpng structures as destroyed by store_write_reset above. |
|
*/ |
|
static png_structp |
|
set_store_for_write(png_store *ps, png_infopp ppi, const char *name) |
|
{ |
|
anon_context(ps); |
|
|
|
Try |
|
{ |
|
if (ps->pwrite != NULL) |
|
png_error(ps->pwrite, "write store already in use"); |
|
|
|
store_write_reset(ps); |
|
safecat(ps->wname, sizeof ps->wname, 0, name); |
|
|
|
/* Don't do the slow memory checks if doing a speed test, also if user |
|
* memory is not supported we can't do it anyway. |
|
*/ |
|
# ifdef PNG_USER_MEM_SUPPORTED |
|
if (!ps->speed) |
|
ps->pwrite = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, |
|
ps, store_error, store_warning, &ps->write_memory_pool, |
|
store_malloc, store_free); |
|
|
|
else |
|
# endif |
|
ps->pwrite = png_create_write_struct(PNG_LIBPNG_VER_STRING, |
|
ps, store_error, store_warning); |
|
|
|
png_set_write_fn(ps->pwrite, ps, store_write, store_flush); |
|
|
|
# ifdef PNG_SET_OPTION_SUPPORTED |
|
{ |
|
int opt; |
|
for (opt=0; opt<ps->noptions; ++opt) |
|
if (png_set_option(ps->pwrite, ps->options[opt].option, |
|
ps->options[opt].setting) == PNG_OPTION_INVALID) |
|
png_error(ps->pwrite, "png option invalid"); |
|
} |
|
# endif |
|
|
|
if (ppi != NULL) |
|
*ppi = ps->piwrite = png_create_info_struct(ps->pwrite); |
|
} |
|
|
|
Catch_anonymous |
|
return NULL; |
|
|
|
return ps->pwrite; |
|
} |
|
|
|
/* Cleanup when finished reading (either due to error or in the success case). |
|
* This routine exists even when there is no read support to make the code |
|
* tidier (avoid a mass of ifdefs) and so easier to maintain. |
|
*/ |
|
static void |
|
store_read_reset(png_store *ps) |
|
{ |
|
# ifdef PNG_READ_SUPPORTED |
|
if (ps->pread != NULL) |
|
{ |
|
anon_context(ps); |
|
|
|
Try |
|
png_destroy_read_struct(&ps->pread, &ps->piread, NULL); |
|
|
|
Catch_anonymous |
|
{ |
|
/* error already output: continue */ |
|
} |
|
|
|
ps->pread = NULL; |
|
ps->piread = NULL; |
|
} |
|
# endif |
|
|
|
# ifdef PNG_USER_MEM_SUPPORTED |
|
/* Always do this to be safe. */ |
|
store_pool_delete(ps, &ps->read_memory_pool); |
|
# endif |
|
|
|
ps->current = NULL; |
|
ps->next = NULL; |
|
ps->readpos = 0; |
|
ps->validated = 0; |
|
|
|
ps->chunkpos = 8; |
|
ps->chunktype = 0; |
|
ps->chunklen = 16; |
|
ps->IDAT_size = 0; |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static void |
|
store_read_set(png_store *ps, png_uint_32 id) |
|
{ |
|
png_store_file *pf = ps->saved; |
|
|
|
while (pf != NULL) |
|
{ |
|
if (pf->id == id) |
|
{ |
|
ps->current = pf; |
|
ps->next = NULL; |
|
ps->IDAT_size = pf->IDAT_size; |
|
ps->IDAT_bits = pf->IDAT_bits; /* just a cache */ |
|
ps->IDAT_len = 0; |
|
ps->IDAT_pos = 0; |
|
ps->IDAT_crc = 0UL; |
|
store_read_buffer_next(ps); |
|
return; |
|
} |
|
|
|
pf = pf->next; |
|
} |
|
|
|
{ |
|
size_t pos; |
|
char msg[FILE_NAME_SIZE+64]; |
|
|
|
pos = standard_name_from_id(msg, sizeof msg, 0, id); |
|
pos = safecat(msg, sizeof msg, pos, ": file not found"); |
|
png_error(ps->pread, msg); |
|
} |
|
} |
|
|
|
/* The main interface for reading a saved file - pass the id number of the file |
|
* to retrieve. Ids must be unique or the earlier file will be hidden. The API |
|
* returns a png_struct and, optionally, a png_info. Both of these will be |
|
* destroyed by store_read_reset above. |
|
*/ |
|
static png_structp |
|
set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, |
|
const char *name) |
|
{ |
|
/* Set the name for png_error */ |
|
safecat(ps->test, sizeof ps->test, 0, name); |
|
|
|
if (ps->pread != NULL) |
|
png_error(ps->pread, "read store already in use"); |
|
|
|
store_read_reset(ps); |
|
|
|
/* Both the create APIs can return NULL if used in their default mode |
|
* (because there is no other way of handling an error because the jmp_buf |
|
* by default is stored in png_struct and that has not been allocated!) |
|
* However, given that store_error works correctly in these circumstances |
|
* we don't ever expect NULL in this program. |
|
*/ |
|
# ifdef PNG_USER_MEM_SUPPORTED |
|
if (!ps->speed) |
|
ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, |
|
store_error, store_warning, &ps->read_memory_pool, store_malloc, |
|
store_free); |
|
|
|
else |
|
# endif |
|
ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error, |
|
store_warning); |
|
|
|
if (ps->pread == NULL) |
|
{ |
|
struct exception_context *the_exception_context = &ps->exception_context; |
|
|
|
store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", |
|
1 /*error*/); |
|
|
|
Throw ps; |
|
} |
|
|
|
# ifdef PNG_SET_OPTION_SUPPORTED |
|
{ |
|
int opt; |
|
for (opt=0; opt<ps->noptions; ++opt) |
|
if (png_set_option(ps->pread, ps->options[opt].option, |
|
ps->options[opt].setting) == PNG_OPTION_INVALID) |
|
png_error(ps->pread, "png option invalid"); |
|
} |
|
# endif |
|
|
|
store_read_set(ps, id); |
|
|
|
if (ppi != NULL) |
|
*ppi = ps->piread = png_create_info_struct(ps->pread); |
|
|
|
return ps->pread; |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* The overall cleanup of a store simply calls the above then removes all the |
|
* saved files. This does not delete the store itself. |
|
*/ |
|
static void |
|
store_delete(png_store *ps) |
|
{ |
|
store_write_reset(ps); |
|
store_read_reset(ps); |
|
store_freefile(&ps->saved); |
|
store_image_free(ps, NULL); |
|
} |
|
|
|
/*********************** PNG FILE MODIFICATION ON READ ************************/ |
|
/* Files may be modified on read. The following structure contains a complete |
|
* png_store together with extra members to handle modification and a special |
|
* read callback for libpng. To use this the 'modifications' field must be set |
|
* to a list of png_modification structures that actually perform the |
|
* modification, otherwise a png_modifier is functionally equivalent to a |
|
* png_store. There is a special read function, set_modifier_for_read, which |
|
* replaces set_store_for_read. |
|
*/ |
|
typedef enum modifier_state |
|
{ |
|
modifier_start, /* Initial value */ |
|
modifier_signature, /* Have a signature */ |
|
modifier_IHDR /* Have an IHDR */ |
|
} modifier_state; |
|
|
|
typedef struct CIE_color |
|
{ |
|
/* A single CIE tristimulus value, representing the unique response of a |
|
* standard observer to a variety of light spectra. The observer recognizes |
|
* all spectra that produce this response as the same color, therefore this |
|
* is effectively a description of a color. |
|
*/ |
|
double X, Y, Z; |
|
} CIE_color; |
|
|
|
typedef struct color_encoding |
|
{ |
|
/* A description of an (R,G,B) encoding of color (as defined above); this |
|
* includes the actual colors of the (R,G,B) triples (1,0,0), (0,1,0) and |
|
* (0,0,1) plus an encoding value that is used to encode the linear |
|
* components R, G and B to give the actual values R^gamma, G^gamma and |
|
* B^gamma that are stored. |
|
*/ |
|
double gamma; /* Encoding (file) gamma of space */ |
|
CIE_color red, green, blue; /* End points */ |
|
} color_encoding; |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
#if defined PNG_READ_TRANSFORMS_SUPPORTED && defined PNG_READ_cHRM_SUPPORTED |
|
static double |
|
chromaticity_x(CIE_color c) |
|
{ |
|
return c.X / (c.X + c.Y + c.Z); |
|
} |
|
|
|
static double |
|
chromaticity_y(CIE_color c) |
|
{ |
|
return c.Y / (c.X + c.Y + c.Z); |
|
} |
|
|
|
static CIE_color |
|
white_point(const color_encoding *encoding) |
|
{ |
|
CIE_color white; |
|
|
|
white.X = encoding->red.X + encoding->green.X + encoding->blue.X; |
|
white.Y = encoding->red.Y + encoding->green.Y + encoding->blue.Y; |
|
white.Z = encoding->red.Z + encoding->green.Z + encoding->blue.Z; |
|
|
|
return white; |
|
} |
|
#endif /* READ_TRANSFORMS && READ_cHRM */ |
|
|
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
static void |
|
normalize_color_encoding(color_encoding *encoding) |
|
{ |
|
const double whiteY = encoding->red.Y + encoding->green.Y + |
|
encoding->blue.Y; |
|
|
|
if (whiteY != 1) |
|
{ |
|
encoding->red.X /= whiteY; |
|
encoding->red.Y /= whiteY; |
|
encoding->red.Z /= whiteY; |
|
encoding->green.X /= whiteY; |
|
encoding->green.Y /= whiteY; |
|
encoding->green.Z /= whiteY; |
|
encoding->blue.X /= whiteY; |
|
encoding->blue.Y /= whiteY; |
|
encoding->blue.Z /= whiteY; |
|
} |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
static size_t |
|
safecat_color_encoding(char *buffer, size_t bufsize, size_t pos, |
|
const color_encoding *e, double encoding_gamma) |
|
{ |
|
if (e != 0) |
|
{ |
|
if (encoding_gamma != 0) |
|
pos = safecat(buffer, bufsize, pos, "("); |
|
pos = safecat(buffer, bufsize, pos, "R("); |
|
pos = safecatd(buffer, bufsize, pos, e->red.X, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->red.Y, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->red.Z, 4); |
|
pos = safecat(buffer, bufsize, pos, "),G("); |
|
pos = safecatd(buffer, bufsize, pos, e->green.X, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->green.Y, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->green.Z, 4); |
|
pos = safecat(buffer, bufsize, pos, "),B("); |
|
pos = safecatd(buffer, bufsize, pos, e->blue.X, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->blue.Y, 4); |
|
pos = safecat(buffer, bufsize, pos, ","); |
|
pos = safecatd(buffer, bufsize, pos, e->blue.Z, 4); |
|
pos = safecat(buffer, bufsize, pos, ")"); |
|
if (encoding_gamma != 0) |
|
pos = safecat(buffer, bufsize, pos, ")"); |
|
} |
|
|
|
if (encoding_gamma != 0) |
|
{ |
|
pos = safecat(buffer, bufsize, pos, "^"); |
|
pos = safecatd(buffer, bufsize, pos, encoding_gamma, 5); |
|
} |
|
|
|
return pos; |
|
} |
|
#endif /* READ_TRANSFORMS */ |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
typedef struct png_modifier |
|
{ |
|
png_store this; /* I am a png_store */ |
|
struct png_modification *modifications; /* Changes to make */ |
|
|
|
modifier_state state; /* My state */ |
|
|
|
/* Information from IHDR: */ |
|
png_byte bit_depth; /* From IHDR */ |
|
png_byte colour_type; /* From IHDR */ |
|
|
|
/* While handling PLTE, IDAT and IEND these chunks may be pended to allow |
|
* other chunks to be inserted. |
|
*/ |
|
png_uint_32 pending_len; |
|
png_uint_32 pending_chunk; |
|
|
|
/* Test values */ |
|
double *gammas; |
|
unsigned int ngammas; |
|
unsigned int ngamma_tests; /* Number of gamma tests to run*/ |
|
double current_gamma; /* 0 if not set */ |
|
const color_encoding *encodings; |
|
unsigned int nencodings; |
|
const color_encoding *current_encoding; /* If an encoding has been set */ |
|
unsigned int encoding_counter; /* For iteration */ |
|
int encoding_ignored; /* Something overwrote it */ |
|
|
|
/* Control variables used to iterate through possible encodings, the |
|
* following must be set to 0 and tested by the function that uses the |
|
* png_modifier because the modifier only sets it to 1 (true.) |
|
*/ |
|
unsigned int repeat :1; /* Repeat this transform test. */ |
|
unsigned int test_uses_encoding :1; |
|
|
|
/* Lowest sbit to test (pre-1.7 libpng fails for sbit < 8) */ |
|
png_byte sbitlow; |
|
|
|
/* Error control - these are the limits on errors accepted by the gamma tests |
|
* below. |
|
*/ |
|
double maxout8; /* Maximum output value error */ |
|
double maxabs8; /* Absolute sample error 0..1 */ |
|
double maxcalc8; /* Absolute sample error 0..1 */ |
|
double maxpc8; /* Percentage sample error 0..100% */ |
|
double maxout16; /* Maximum output value error */ |
|
double maxabs16; /* Absolute sample error 0..1 */ |
|
double maxcalc16;/* Absolute sample error 0..1 */ |
|
double maxcalcG; /* Absolute sample error 0..1 */ |
|
double maxpc16; /* Percentage sample error 0..100% */ |
|
|
|
/* This is set by transforms that need to allow a higher limit, it is an |
|
* internal check on pngvalid to ensure that the calculated error limits are |
|
* not ridiculous; without this it is too easy to make a mistake in pngvalid |
|
* that allows any value through. |
|
* |
|
* NOTE: this is not checked in release builds. |
|
*/ |
|
double limit; /* limit on error values, normally 4E-3 */ |
|
|
|
/* Log limits - values above this are logged, but not necessarily |
|
* warned. |
|
*/ |
|
double log8; /* Absolute error in 8 bits to log */ |
|
double log16; /* Absolute error in 16 bits to log */ |
|
|
|
/* Logged 8 and 16 bit errors ('output' values): */ |
|
double error_gray_2; |
|
double error_gray_4; |
|
double error_gray_8; |
|
double error_gray_16; |
|
double error_color_8; |
|
double error_color_16; |
|
double error_indexed; |
|
|
|
/* Flags: */ |
|
/* Whether to call png_read_update_info, not png_read_start_image, and how |
|
* many times to call it. |
|
*/ |
|
int use_update_info; |
|
|
|
/* Whether or not to interlace. */ |
|
int interlace_type :9; /* int, but must store '1' */ |
|
|
|
/* Run the standard tests? */ |
|
unsigned int test_standard :1; |
|
|
|
/* Run the odd-sized image and interlace read/write tests? */ |
|
unsigned int test_size :1; |
|
|
|
/* Run tests on reading with a combination of transforms, */ |
|
unsigned int test_transform :1; |
|
unsigned int test_tRNS :1; /* Includes tRNS images */ |
|
|
|
/* When to use the use_input_precision option, this controls the gamma |
|
* validation code checks. If set any value that is within the transformed |
|
* range input-.5 to input+.5 will be accepted, otherwise the value must be |
|
* within the normal limits. It should not be necessary to set this; the |
|
* result should always be exact within the permitted error limits. |
|
*/ |
|
unsigned int use_input_precision :1; |
|
unsigned int use_input_precision_sbit :1; |
|
unsigned int use_input_precision_16to8 :1; |
|
|
|
/* If set assume that the calculation bit depth is set by the input |
|
* precision, not the output precision. |
|
*/ |
|
unsigned int calculations_use_input_precision :1; |
|
|
|
/* If set assume that the calculations are done in 16 bits even if the sample |
|
* depth is 8 bits. |
|
*/ |
|
unsigned int assume_16_bit_calculations :1; |
|
|
|
/* Which gamma tests to run: */ |
|
unsigned int test_gamma_threshold :1; |
|
unsigned int test_gamma_transform :1; /* main tests */ |
|
unsigned int test_gamma_sbit :1; |
|
unsigned int test_gamma_scale16 :1; |
|
unsigned int test_gamma_background :1; |
|
unsigned int test_gamma_alpha_mode :1; |
|
unsigned int test_gamma_expand16 :1; |
|
unsigned int test_exhaustive :1; |
|
|
|
/* Whether or not to run the low-bit-depth grayscale tests. This fails on |
|
* gamma images in some cases because of gross inaccuracies in the grayscale |
|
* gamma handling for low bit depth. |
|
*/ |
|
unsigned int test_lbg :1; |
|
unsigned int test_lbg_gamma_threshold :1; |
|
unsigned int test_lbg_gamma_transform :1; |
|
unsigned int test_lbg_gamma_sbit :1; |
|
unsigned int test_lbg_gamma_composition :1; |
|
|
|
unsigned int log :1; /* Log max error */ |
|
|
|
/* Buffer information, the buffer size limits the size of the chunks that can |
|
* be modified - they must fit (including header and CRC) into the buffer! |
|
*/ |
|
size_t flush; /* Count of bytes to flush */ |
|
size_t buffer_count; /* Bytes in buffer */ |
|
size_t buffer_position; /* Position in buffer */ |
|
png_byte buffer[1024]; |
|
} png_modifier; |
|
|
|
/* This returns true if the test should be stopped now because it has already |
|
* failed and it is running silently. |
|
*/ |
|
static int fail(png_modifier *pm) |
|
{ |
|
return !pm->log && !pm->this.verbose && (pm->this.nerrors > 0 || |
|
(pm->this.treat_warnings_as_errors && pm->this.nwarnings > 0)); |
|
} |
|
|
|
static void |
|
modifier_init(png_modifier *pm) |
|
{ |
|
memset(pm, 0, sizeof *pm); |
|
store_init(&pm->this); |
|
pm->modifications = NULL; |
|
pm->state = modifier_start; |
|
pm->sbitlow = 1U; |
|
pm->ngammas = 0; |
|
pm->ngamma_tests = 0; |
|
pm->gammas = 0; |
|
pm->current_gamma = 0; |
|
pm->encodings = 0; |
|
pm->nencodings = 0; |
|
pm->current_encoding = 0; |
|
pm->encoding_counter = 0; |
|
pm->encoding_ignored = 0; |
|
pm->repeat = 0; |
|
pm->test_uses_encoding = 0; |
|
pm->maxout8 = pm->maxpc8 = pm->maxabs8 = pm->maxcalc8 = 0; |
|
pm->maxout16 = pm->maxpc16 = pm->maxabs16 = pm->maxcalc16 = 0; |
|
pm->maxcalcG = 0; |
|
pm->limit = 4E-3; |
|
pm->log8 = pm->log16 = 0; /* Means 'off' */ |
|
pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = 0; |
|
pm->error_gray_16 = pm->error_color_8 = pm->error_color_16 = 0; |
|
pm->error_indexed = 0; |
|
pm->use_update_info = 0; |
|
pm->interlace_type = PNG_INTERLACE_NONE; |
|
pm->test_standard = 0; |
|
pm->test_size = 0; |
|
pm->test_transform = 0; |
|
# ifdef PNG_WRITE_tRNS_SUPPORTED |
|
pm->test_tRNS = 1; |
|
# else |
|
pm->test_tRNS = 0; |
|
# endif |
|
pm->use_input_precision = 0; |
|
pm->use_input_precision_sbit = 0; |
|
pm->use_input_precision_16to8 = 0; |
|
pm->calculations_use_input_precision = 0; |
|
pm->assume_16_bit_calculations = 0; |
|
pm->test_gamma_threshold = 0; |
|
pm->test_gamma_transform = 0; |
|
pm->test_gamma_sbit = 0; |
|
pm->test_gamma_scale16 = 0; |
|
pm->test_gamma_background = 0; |
|
pm->test_gamma_alpha_mode = 0; |
|
pm->test_gamma_expand16 = 0; |
|
pm->test_lbg = 1; |
|
pm->test_lbg_gamma_threshold = 1; |
|
pm->test_lbg_gamma_transform = 1; |
|
pm->test_lbg_gamma_sbit = 1; |
|
pm->test_lbg_gamma_composition = 1; |
|
pm->test_exhaustive = 0; |
|
pm->log = 0; |
|
|
|
/* Rely on the memset for all the other fields - there are no pointers */ |
|
} |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
|
|
/* This controls use of checks that explicitly know how libpng digitizes the |
|
* samples in calculations; setting this circumvents simple error limit checking |
|
* in the rgb_to_gray check, replacing it with an exact copy of the libpng 1.5 |
|
* algorithm. |
|
*/ |
|
#define DIGITIZE PNG_LIBPNG_VER < 10700 |
|
|
|
/* If pm->calculations_use_input_precision is set then operations will happen |
|
* with the precision of the input, not the precision of the output depth. |
|
* |
|
* If pm->assume_16_bit_calculations is set then even 8 bit calculations use 16 |
|
* bit precision. This only affects those of the following limits that pertain |
|
* to a calculation - not a digitization operation - unless the following API is |
|
* called directly. |
|
*/ |
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
#if DIGITIZE |
|
static double digitize(double value, int depth, int do_round) |
|
{ |
|
/* 'value' is in the range 0 to 1, the result is the same value rounded to a |
|
* multiple of the digitization factor - 8 or 16 bits depending on both the |
|
* sample depth and the 'assume' setting. Digitization is normally by |
|
* rounding and 'do_round' should be 1, if it is 0 the digitized value will |
|
* be truncated. |
|
*/ |
|
unsigned int digitization_factor = (1U << depth) - 1; |
|
|
|
/* Limiting the range is done as a convenience to the caller - it's easier to |
|
* do it once here than every time at the call site. |
|
*/ |
|
if (value <= 0) |
|
value = 0; |
|
|
|
else if (value >= 1) |
|
value = 1; |
|
|
|
value *= digitization_factor; |
|
if (do_round) value += .5; |
|
return floor(value)/digitization_factor; |
|
} |
|
#endif |
|
#endif /* RGB_TO_GRAY */ |
|
|
|
#ifdef PNG_READ_GAMMA_SUPPORTED |
|
static double abserr(const png_modifier *pm, int in_depth, int out_depth) |
|
{ |
|
/* Absolute error permitted in linear values - affected by the bit depth of |
|
* the calculations. |
|
*/ |
|
if (pm->assume_16_bit_calculations || |
|
(pm->calculations_use_input_precision ? in_depth : out_depth) == 16) |
|
return pm->maxabs16; |
|
else |
|
return pm->maxabs8; |
|
} |
|
|
|
static double calcerr(const png_modifier *pm, int in_depth, int out_depth) |
|
{ |
|
/* Error in the linear composition arithmetic - only relevant when |
|
* composition actually happens (0 < alpha < 1). |
|
*/ |
|
if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) |
|
return pm->maxcalc16; |
|
else if (pm->assume_16_bit_calculations) |
|
return pm->maxcalcG; |
|
else |
|
return pm->maxcalc8; |
|
} |
|
|
|
static double pcerr(const png_modifier *pm, int in_depth, int out_depth) |
|
{ |
|
/* Percentage error permitted in the linear values. Note that the specified |
|
* value is a percentage but this routine returns a simple number. |
|
*/ |
|
if (pm->assume_16_bit_calculations || |
|
(pm->calculations_use_input_precision ? in_depth : out_depth) == 16) |
|
return pm->maxpc16 * .01; |
|
else |
|
return pm->maxpc8 * .01; |
|
} |
|
|
|
/* Output error - the error in the encoded value. This is determined by the |
|
* digitization of the output so can be +/-0.5 in the actual output value. In |
|
* the expand_16 case with the current code in libpng the expand happens after |
|
* all the calculations are done in 8 bit arithmetic, so even though the output |
|
* depth is 16 the output error is determined by the 8 bit calculation. |
|
* |
|
* This limit is not determined by the bit depth of internal calculations. |
|
* |
|
* The specified parameter does *not* include the base .5 digitization error but |
|
* it is added here. |
|
*/ |
|
static double outerr(const png_modifier *pm, int in_depth, int out_depth) |
|
{ |
|
/* There is a serious error in the 2 and 4 bit grayscale transform because |
|
* the gamma table value (8 bits) is simply shifted, not rounded, so the |
|
* error in 4 bit grayscale gamma is up to the value below. This is a hack |
|
* to allow pngvalid to succeed: |
|
* |
|
* TODO: fix this in libpng |
|
*/ |
|
if (out_depth == 2) |
|
return .73182-.5; |
|
|
|
if (out_depth == 4) |
|
return .90644-.5; |
|
|
|
if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) |
|
return pm->maxout16; |
|
|
|
/* This is the case where the value was calculated at 8-bit precision then |
|
* scaled to 16 bits. |
|
*/ |
|
else if (out_depth == 16) |
|
return pm->maxout8 * 257; |
|
|
|
else |
|
return pm->maxout8; |
|
} |
|
|
|
/* This does the same thing as the above however it returns the value to log, |
|
* rather than raising a warning. This is useful for debugging to track down |
|
* exactly what set of parameters cause high error values. |
|
*/ |
|
static double outlog(const png_modifier *pm, int in_depth, int out_depth) |
|
{ |
|
/* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) |
|
* and so must be adjusted for low bit depth grayscale: |
|
*/ |
|
if (out_depth <= 8) |
|
{ |
|
if (pm->log8 == 0) /* switched off */ |
|
return 256; |
|
|
|
if (out_depth < 8) |
|
return pm->log8 / 255 * ((1<<out_depth)-1); |
|
|
|
return pm->log8; |
|
} |
|
|
|
if ((pm->calculations_use_input_precision ? in_depth : out_depth) == 16) |
|
{ |
|
if (pm->log16 == 0) |
|
return 65536; |
|
|
|
return pm->log16; |
|
} |
|
|
|
/* This is the case where the value was calculated at 8-bit precision then |
|
* scaled to 16 bits. |
|
*/ |
|
if (pm->log8 == 0) |
|
return 65536; |
|
|
|
return pm->log8 * 257; |
|
} |
|
|
|
/* This complements the above by providing the appropriate quantization for the |
|
* final value. Normally this would just be quantization to an integral value, |
|
* but in the 8 bit calculation case it's actually quantization to a multiple of |
|
* 257! |
|
*/ |
|
static int output_quantization_factor(const png_modifier *pm, int in_depth, |
|
int out_depth) |
|
{ |
|
if (out_depth == 16 && in_depth != 16 && |
|
pm->calculations_use_input_precision) |
|
return 257; |
|
else |
|
return 1; |
|
} |
|
#endif /* PNG_READ_GAMMA_SUPPORTED */ |
|
|
|
/* One modification structure must be provided for each chunk to be modified (in |
|
* fact more than one can be provided if multiple separate changes are desired |
|
* for a single chunk.) Modifications include adding a new chunk when a |
|
* suitable chunk does not exist. |
|
* |
|
* The caller of modify_fn will reset the CRC of the chunk and record 'modified' |
|
* or 'added' as appropriate if the modify_fn returns 1 (true). If the |
|
* modify_fn is NULL the chunk is simply removed. |
|
*/ |
|
typedef struct png_modification |
|
{ |
|
struct png_modification *next; |
|
png_uint_32 chunk; |
|
|
|
/* If the following is NULL all matching chunks will be removed: */ |
|
int (*modify_fn)(struct png_modifier *pm, |
|
struct png_modification *me, int add); |
|
|
|
/* If the following is set to PLTE, IDAT or IEND and the chunk has not been |
|
* found and modified (and there is a modify_fn) the modify_fn will be called |
|
* to add the chunk before the relevant chunk. |
|
*/ |
|
png_uint_32 add; |
|
unsigned int modified :1; /* Chunk was modified */ |
|
unsigned int added :1; /* Chunk was added */ |
|
unsigned int removed :1; /* Chunk was removed */ |
|
} png_modification; |
|
|
|
static void |
|
modification_reset(png_modification *pmm) |
|
{ |
|
if (pmm != NULL) |
|
{ |
|
pmm->modified = 0; |
|
pmm->added = 0; |
|
pmm->removed = 0; |
|
modification_reset(pmm->next); |
|
} |
|
} |
|
|
|
static void |
|
modification_init(png_modification *pmm) |
|
{ |
|
memset(pmm, 0, sizeof *pmm); |
|
pmm->next = NULL; |
|
pmm->chunk = 0; |
|
pmm->modify_fn = NULL; |
|
pmm->add = 0; |
|
modification_reset(pmm); |
|
} |
|
|
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
static void |
|
modifier_current_encoding(const png_modifier *pm, color_encoding *ce) |
|
{ |
|
if (pm->current_encoding != 0) |
|
*ce = *pm->current_encoding; |
|
|
|
else |
|
memset(ce, 0, sizeof *ce); |
|
|
|
ce->gamma = pm->current_gamma; |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
static size_t |
|
safecat_current_encoding(char *buffer, size_t bufsize, size_t pos, |
|
const png_modifier *pm) |
|
{ |
|
pos = safecat_color_encoding(buffer, bufsize, pos, pm->current_encoding, |
|
pm->current_gamma); |
|
|
|
if (pm->encoding_ignored) |
|
pos = safecat(buffer, bufsize, pos, "[overridden]"); |
|
|
|
return pos; |
|
} |
|
#endif |
|
|
|
/* Iterate through the usefully testable color encodings. An encoding is one |
|
* of: |
|
* |
|
* 1) Nothing (no color space, no gamma). |
|
* 2) Just a gamma value from the gamma array (including 1.0) |
|
* 3) A color space from the encodings array with the corresponding gamma. |
|
* 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) |
|
* |
|
* The iterator selects these in turn, the randomizer selects one at random, |
|
* which is used depends on the setting of the 'test_exhaustive' flag. Notice |
|
* that this function changes the colour space encoding so it must only be |
|
* called on completion of the previous test. This is what 'modifier_reset' |
|
* does, below. |
|
* |
|
* After the function has been called the 'repeat' flag will still be set; the |
|
* caller of modifier_reset must reset it at the start of each run of the test! |
|
*/ |
|
static unsigned int |
|
modifier_total_encodings(const png_modifier *pm) |
|
{ |
|
return 1 + /* (1) nothing */ |
|
pm->ngammas + /* (2) gamma values to test */ |
|
pm->nencodings + /* (3) total number of encodings */ |
|
/* The following test only works after the first time through the |
|
* png_modifier code because 'bit_depth' is set when the IHDR is read. |
|
* modifier_reset, below, preserves the setting until after it has called |
|
* the iterate function (also below.) |
|
* |
|
* For this reason do not rely on this function outside a call to |
|
* modifier_reset. |
|
*/ |
|
((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? |
|
pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ |
|
} |
|
|
|
static void |
|
modifier_encoding_iterate(png_modifier *pm) |
|
{ |
|
if (!pm->repeat && /* Else something needs the current encoding again. */ |
|
pm->test_uses_encoding) /* Some transform is encoding dependent */ |
|
{ |
|
if (pm->test_exhaustive) |
|
{ |
|
if (++pm->encoding_counter >= modifier_total_encodings(pm)) |
|
pm->encoding_counter = 0; /* This will stop the repeat */ |
|
} |
|
|
|
else |
|
{ |
|
/* Not exhaustive - choose an encoding at random; generate a number in |
|
* the range 1..(max-1), so the result is always non-zero: |
|
*/ |
|
if (pm->encoding_counter == 0) |
|
pm->encoding_counter = random_mod(modifier_total_encodings(pm)-1)+1; |
|
else |
|
pm->encoding_counter = 0; |
|
} |
|
|
|
if (pm->encoding_counter > 0) |
|
pm->repeat = 1; |
|
} |
|
|
|
else if (!pm->repeat) |
|
pm->encoding_counter = 0; |
|
} |
|
|
|
static void |
|
modifier_reset(png_modifier *pm) |
|
{ |
|
store_read_reset(&pm->this); |
|
pm->limit = 4E-3; |
|
pm->pending_len = pm->pending_chunk = 0; |
|
pm->flush = pm->buffer_count = pm->buffer_position = 0; |
|
pm->modifications = NULL; |
|
pm->state = modifier_start; |
|
modifier_encoding_iterate(pm); |
|
/* The following must be set in the next run. In particular |
|
* test_uses_encodings must be set in the _ini function of each transform |
|
* that looks at the encodings. (Not the 'add' function!) |
|
*/ |
|
pm->test_uses_encoding = 0; |
|
pm->current_gamma = 0; |
|
pm->current_encoding = 0; |
|
pm->encoding_ignored = 0; |
|
/* These only become value after IHDR is read: */ |
|
pm->bit_depth = pm->colour_type = 0; |
|
} |
|
|
|
/* The following must be called before anything else to get the encoding set up |
|
* on the modifier. In particular it must be called before the transform init |
|
* functions are called. |
|
*/ |
|
static void |
|
modifier_set_encoding(png_modifier *pm) |
|
{ |
|
/* Set the encoding to the one specified by the current encoding counter, |
|
* first clear out all the settings - this corresponds to an encoding_counter |
|
* of 0. |
|
*/ |
|
pm->current_gamma = 0; |
|
pm->current_encoding = 0; |
|
pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ |
|
|
|
/* Now, if required, set the gamma and encoding fields. */ |
|
if (pm->encoding_counter > 0) |
|
{ |
|
/* The gammas[] array is an array of screen gammas, not encoding gammas, |
|
* so we need the inverse: |
|
*/ |
|
if (pm->encoding_counter <= pm->ngammas) |
|
pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; |
|
|
|
else |
|
{ |
|
unsigned int i = pm->encoding_counter - pm->ngammas; |
|
|
|
if (i >= pm->nencodings) |
|
{ |
|
i %= pm->nencodings; |
|
pm->current_gamma = 1; /* Linear, only in the 16 bit case */ |
|
} |
|
|
|
else |
|
pm->current_gamma = pm->encodings[i].gamma; |
|
|
|
pm->current_encoding = pm->encodings + i; |
|
} |
|
} |
|
} |
|
|
|
/* Enquiry functions to find out what is set. Notice that there is an implicit |
|
* assumption below that the first encoding in the list is the one for sRGB. |
|
*/ |
|
static int |
|
modifier_color_encoding_is_sRGB(const png_modifier *pm) |
|
{ |
|
return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && |
|
pm->current_encoding->gamma == pm->current_gamma; |
|
} |
|
|
|
static int |
|
modifier_color_encoding_is_set(const png_modifier *pm) |
|
{ |
|
return pm->current_gamma != 0; |
|
} |
|
|
|
/* The guts of modification are performed during a read. */ |
|
static void |
|
modifier_crc(png_bytep buffer) |
|
{ |
|
/* Recalculate the chunk CRC - a complete chunk must be in |
|
* the buffer, at the start. |
|
*/ |
|
uInt datalen = png_get_uint_32(buffer); |
|
uLong crc = crc32(0, buffer+4, datalen+4); |
|
/* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. |
|
*/ |
|
png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); |
|
} |
|
|
|
static void |
|
modifier_setbuffer(png_modifier *pm) |
|
{ |
|
modifier_crc(pm->buffer); |
|
pm->buffer_count = png_get_uint_32(pm->buffer)+12; |
|
pm->buffer_position = 0; |
|
} |
|
|
|
/* Separate the callback into the actual implementation (which is passed the |
|
* png_modifier explicitly) and the callback, which gets the modifier from the |
|
* png_struct. |
|
*/ |
|
static void |
|
modifier_read_imp(png_modifier *pm, png_bytep pb, size_t st) |
|
{ |
|
while (st > 0) |
|
{ |
|
size_t cb; |
|
png_uint_32 len, chunk; |
|
png_modification *mod; |
|
|
|
if (pm->buffer_position >= pm->buffer_count) switch (pm->state) |
|
{ |
|
static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; |
|
case modifier_start: |
|
store_read_chunk(&pm->this, pm->buffer, 8, 8); /* signature. */ |
|
pm->buffer_count = 8; |
|
pm->buffer_position = 0; |
|
|
|
if (memcmp(pm->buffer, sign, 8) != 0) |
|
png_error(pm->this.pread, "invalid PNG file signature"); |
|
pm->state = modifier_signature; |
|
break; |
|
|
|
case modifier_signature: |
|
store_read_chunk(&pm->this, pm->buffer, 13+12, 13+12); /* IHDR */ |
|
pm->buffer_count = 13+12; |
|
pm->buffer_position = 0; |
|
|
|
if (png_get_uint_32(pm->buffer) != 13 || |
|
png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) |
|
png_error(pm->this.pread, "invalid IHDR"); |
|
|
|
/* Check the list of modifiers for modifications to the IHDR. */ |
|
mod = pm->modifications; |
|
while (mod != NULL) |
|
{ |
|
if (mod->chunk == CHUNK_IHDR && mod->modify_fn && |
|
(*mod->modify_fn)(pm, mod, 0)) |
|
{ |
|
mod->modified = 1; |
|
modifier_setbuffer(pm); |
|
} |
|
|
|
/* Ignore removal or add if IHDR! */ |
|
mod = mod->next; |
|
} |
|
|
|
/* Cache information from the IHDR (the modified one.) */ |
|
pm->bit_depth = pm->buffer[8+8]; |
|
pm->colour_type = pm->buffer[8+8+1]; |
|
|
|
pm->state = modifier_IHDR; |
|
pm->flush = 0; |
|
break; |
|
|
|
case modifier_IHDR: |
|
default: |
|
/* Read a new chunk and process it until we see PLTE, IDAT or |
|
* IEND. 'flush' indicates that there is still some data to |
|
* output from the preceding chunk. |
|
*/ |
|
if ((cb = pm->flush) > 0) |
|
{ |
|
if (cb > st) cb = st; |
|
pm->flush -= cb; |
|
store_read_chunk(&pm->this, pb, cb, cb); |
|
pb += cb; |
|
st -= cb; |
|
if (st == 0) return; |
|
} |
|
|
|
/* No more bytes to flush, read a header, or handle a pending |
|
* chunk. |
|
*/ |
|
if (pm->pending_chunk != 0) |
|
{ |
|
png_save_uint_32(pm->buffer, pm->pending_len); |
|
png_save_uint_32(pm->buffer+4, pm->pending_chunk); |
|
pm->pending_len = 0; |
|
pm->pending_chunk = 0; |
|
} |
|
else |
|
store_read_chunk(&pm->this, pm->buffer, 8, 8); |
|
|
|
pm->buffer_count = 8; |
|
pm->buffer_position = 0; |
|
|
|
/* Check for something to modify or a terminator chunk. */ |
|
len = png_get_uint_32(pm->buffer); |
|
chunk = png_get_uint_32(pm->buffer+4); |
|
|
|
/* Terminators first, they may have to be delayed for added |
|
* chunks |
|
*/ |
|
if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || |
|
chunk == CHUNK_IEND) |
|
{ |
|
mod = pm->modifications; |
|
|
|
while (mod != NULL) |
|
{ |
|
if ((mod->add == chunk || |
|
(mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && |
|
mod->modify_fn != NULL && !mod->modified && !mod->added) |
|
{ |
|
/* Regardless of what the modify function does do not run |
|
* this again. |
|
*/ |
|
mod->added = 1; |
|
|
|
if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) |
|
{ |
|
/* Reset the CRC on a new chunk */ |
|
if (pm->buffer_count > 0) |
|
modifier_setbuffer(pm); |
|
|
|
else |
|
{ |
|
pm->buffer_position = 0; |
|
mod->removed = 1; |
|
} |
|
|
|
/* The buffer has been filled with something (we assume) |
|
* so output this. Pend the current chunk. |
|
*/ |
|
pm->pending_len = len; |
|
pm->pending_chunk = chunk; |
|
break; /* out of while */ |
|
} |
|
} |
|
|
|
mod = mod->next; |
|
} |
|
|
|
/* Don't do any further processing if the buffer was modified - |
|
* otherwise the code will end up modifying a chunk that was |
|
* just added. |
|
*/ |
|
if (mod != NULL) |
|
break; /* out of switch */ |
|
} |
|
|
|
/* If we get to here then this chunk may need to be modified. To |
|
* do this it must be less than 1024 bytes in total size, otherwise |
|
* it just gets flushed. |
|
*/ |
|
if (len+12 <= sizeof pm->buffer) |
|
{ |
|
size_t s = len+12-pm->buffer_count; |
|
store_read_chunk(&pm->this, pm->buffer+pm->buffer_count, s, s); |
|
pm->buffer_count = len+12; |
|
|
|
/* Check for a modification, else leave it be. */ |
|
mod = pm->modifications; |
|
while (mod != NULL) |
|
{ |
|
if (mod->chunk == chunk) |
|
{ |
|
if (mod->modify_fn == NULL) |
|
{ |
|
/* Remove this chunk */ |
|
pm->buffer_count = pm->buffer_position = 0; |
|
mod->removed = 1; |
|
break; /* Terminate the while loop */ |
|
} |
|
|
|
else if ((*mod->modify_fn)(pm, mod, 0)) |
|
{ |
|
mod->modified = 1; |
|
/* The chunk may have been removed: */ |
|
if (pm->buffer_count == 0) |
|
{ |
|
pm->buffer_position = 0; |
|
break; |
|
} |
|
modifier_setbuffer(pm); |
|
} |
|
} |
|
|
|
mod = mod->next; |
|
} |
|
} |
|
|
|
else |
|
pm->flush = len+12 - pm->buffer_count; /* data + crc */ |
|
|
|
/* Take the data from the buffer (if there is any). */ |
|
break; |
|
} |
|
|
|
/* Here to read from the modifier buffer (not directly from |
|
* the store, as in the flush case above.) |
|
*/ |
|
cb = pm->buffer_count - pm->buffer_position; |
|
|
|
if (cb > st) |
|
cb = st; |
|
|
|
memcpy(pb, pm->buffer + pm->buffer_position, cb); |
|
st -= cb; |
|
pb += cb; |
|
pm->buffer_position += cb; |
|
} |
|
} |
|
|
|
/* The callback: */ |
|
static void PNGCBAPI |
|
modifier_read(png_structp ppIn, png_bytep pb, size_t st) |
|
{ |
|
png_const_structp pp = ppIn; |
|
png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); |
|
|
|
if (pm == NULL || pm->this.pread != pp) |
|
png_error(pp, "bad modifier_read call"); |
|
|
|
modifier_read_imp(pm, pb, st); |
|
} |
|
|
|
/* Like store_progressive_read but the data is getting changed as we go so we |
|
* need a local buffer. |
|
*/ |
|
static void |
|
modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) |
|
{ |
|
if (pm->this.pread != pp || pm->this.current == NULL || |
|
pm->this.next == NULL) |
|
png_error(pp, "store state damaged (progressive)"); |
|
|
|
/* This is another Horowitz and Hill random noise generator. In this case |
|
* the aim is to stress the progressive reader with truly horrible variable |
|
* buffer sizes in the range 1..500, so a sequence of 9 bit random numbers |
|
* is generated. We could probably just count from 1 to 32767 and get as |
|
* good a result. |
|
*/ |
|
for (;;) |
|
{ |
|
static png_uint_32 noise = 1; |
|
size_t cb, cbAvail; |
|
png_byte buffer[512]; |
|
|
|
/* Generate 15 more bits of stuff: */ |
|
noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); |
|
cb = noise & 0x1ff; |
|
|
|
/* Check that this number of bytes are available (in the current buffer.) |
|
* (This doesn't quite work - the modifier might delete a chunk; unlikely |
|
* but possible, it doesn't happen at present because the modifier only |
|
* adds chunks to standard images.) |
|
*/ |
|
cbAvail = store_read_buffer_avail(&pm->this); |
|
if (pm->buffer_count > pm->buffer_position) |
|
cbAvail += pm->buffer_count - pm->buffer_position; |
|
|
|
if (cb > cbAvail) |
|
{ |
|
/* Check for EOF: */ |
|
if (cbAvail == 0) |
|
break; |
|
|
|
cb = cbAvail; |
|
} |
|
|
|
modifier_read_imp(pm, buffer, cb); |
|
png_process_data(pp, pi, buffer, cb); |
|
} |
|
|
|
/* Check the invariants at the end (if this fails it's a problem in this |
|
* file!) |
|
*/ |
|
if (pm->buffer_count > pm->buffer_position || |
|
pm->this.next != &pm->this.current->data || |
|
pm->this.readpos < pm->this.current->datacount) |
|
png_error(pp, "progressive read implementation error"); |
|
} |
|
|
|
/* Set up a modifier. */ |
|
static png_structp |
|
set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, |
|
const char *name) |
|
{ |
|
/* Do this first so that the modifier fields are cleared even if an error |
|
* happens allocating the png_struct. No allocation is done here so no |
|
* cleanup is required. |
|
*/ |
|
pm->state = modifier_start; |
|
pm->bit_depth = 0; |
|
pm->colour_type = 255; |
|
|
|
pm->pending_len = 0; |
|
pm->pending_chunk = 0; |
|
pm->flush = 0; |
|
pm->buffer_count = 0; |
|
pm->buffer_position = 0; |
|
|
|
return set_store_for_read(&pm->this, ppi, id, name); |
|
} |
|
|
|
|
|
/******************************** MODIFICATIONS *******************************/ |
|
/* Standard modifications to add chunks. These do not require the _SUPPORTED |
|
* macros because the chunks can be there regardless of whether this specific |
|
* libpng supports them. |
|
*/ |
|
typedef struct gama_modification |
|
{ |
|
png_modification this; |
|
png_fixed_point gamma; |
|
} gama_modification; |
|
|
|
static int |
|
gama_modify(png_modifier *pm, png_modification *me, int add) |
|
{ |
|
UNUSED(add) |
|
/* This simply dumps the given gamma value into the buffer. */ |
|
png_save_uint_32(pm->buffer, 4); |
|
png_save_uint_32(pm->buffer+4, CHUNK_gAMA); |
|
png_save_uint_32(pm->buffer+8, ((gama_modification*)me)->gamma); |
|
return 1; |
|
} |
|
|
|
static void |
|
gama_modification_init(gama_modification *me, png_modifier *pm, double gammad) |
|
{ |
|
double g; |
|
|
|
modification_init(&me->this); |
|
me->this.chunk = CHUNK_gAMA; |
|
me->this.modify_fn = gama_modify; |
|
me->this.add = CHUNK_PLTE; |
|
g = fix(gammad); |
|
me->gamma = (png_fixed_point)g; |
|
me->this.next = pm->modifications; |
|
pm->modifications = &me->this; |
|
} |
|
|
|
typedef struct chrm_modification |
|
{ |
|
png_modification this; |
|
const color_encoding *encoding; |
|
png_fixed_point wx, wy, rx, ry, gx, gy, bx, by; |
|
} chrm_modification; |
|
|
|
static int |
|
chrm_modify(png_modifier *pm, png_modification *me, int add) |
|
{ |
|
UNUSED(add) |
|
/* As with gAMA this just adds the required cHRM chunk to the buffer. */ |
|
png_save_uint_32(pm->buffer , 32); |
|
png_save_uint_32(pm->buffer+ 4, CHUNK_cHRM); |
|
png_save_uint_32(pm->buffer+ 8, ((chrm_modification*)me)->wx); |
|
png_save_uint_32(pm->buffer+12, ((chrm_modification*)me)->wy); |
|
png_save_uint_32(pm->buffer+16, ((chrm_modification*)me)->rx); |
|
png_save_uint_32(pm->buffer+20, ((chrm_modification*)me)->ry); |
|
png_save_uint_32(pm->buffer+24, ((chrm_modification*)me)->gx); |
|
png_save_uint_32(pm->buffer+28, ((chrm_modification*)me)->gy); |
|
png_save_uint_32(pm->buffer+32, ((chrm_modification*)me)->bx); |
|
png_save_uint_32(pm->buffer+36, ((chrm_modification*)me)->by); |
|
return 1; |
|
} |
|
|
|
static void |
|
chrm_modification_init(chrm_modification *me, png_modifier *pm, |
|
const color_encoding *encoding) |
|
{ |
|
CIE_color white = white_point(encoding); |
|
|
|
/* Original end points: */ |
|
me->encoding = encoding; |
|
|
|
/* Chromaticities (in fixed point): */ |
|
me->wx = fix(chromaticity_x(white)); |
|
me->wy = fix(chromaticity_y(white)); |
|
|
|
me->rx = fix(chromaticity_x(encoding->red)); |
|
me->ry = fix(chromaticity_y(encoding->red)); |
|
me->gx = fix(chromaticity_x(encoding->green)); |
|
me->gy = fix(chromaticity_y(encoding->green)); |
|
me->bx = fix(chromaticity_x(encoding->blue)); |
|
me->by = fix(chromaticity_y(encoding->blue)); |
|
|
|
modification_init(&me->this); |
|
me->this.chunk = CHUNK_cHRM; |
|
me->this.modify_fn = chrm_modify; |
|
me->this.add = CHUNK_PLTE; |
|
me->this.next = pm->modifications; |
|
pm->modifications = &me->this; |
|
} |
|
|
|
typedef struct srgb_modification |
|
{ |
|
png_modification this; |
|
png_byte intent; |
|
} srgb_modification; |
|
|
|
static int |
|
srgb_modify(png_modifier *pm, png_modification *me, int add) |
|
{ |
|
UNUSED(add) |
|
/* As above, ignore add and just make a new chunk */ |
|
png_save_uint_32(pm->buffer, 1); |
|
png_save_uint_32(pm->buffer+4, CHUNK_sRGB); |
|
pm->buffer[8] = ((srgb_modification*)me)->intent; |
|
return 1; |
|
} |
|
|
|
static void |
|
srgb_modification_init(srgb_modification *me, png_modifier *pm, png_byte intent) |
|
{ |
|
modification_init(&me->this); |
|
me->this.chunk = CHUNK_sBIT; |
|
|
|
if (intent <= 3) /* if valid, else *delete* sRGB chunks */ |
|
{ |
|
me->this.modify_fn = srgb_modify; |
|
me->this.add = CHUNK_PLTE; |
|
me->intent = intent; |
|
} |
|
|
|
else |
|
{ |
|
me->this.modify_fn = 0; |
|
me->this.add = 0; |
|
me->intent = 0; |
|
} |
|
|
|
me->this.next = pm->modifications; |
|
pm->modifications = &me->this; |
|
} |
|
|
|
#ifdef PNG_READ_GAMMA_SUPPORTED |
|
typedef struct sbit_modification |
|
{ |
|
png_modification this; |
|
png_byte sbit; |
|
} sbit_modification; |
|
|
|
static int |
|
sbit_modify(png_modifier *pm, png_modification *me, int add) |
|
{ |
|
png_byte sbit = ((sbit_modification*)me)->sbit; |
|
if (pm->bit_depth > sbit) |
|
{ |
|
int cb = 0; |
|
switch (pm->colour_type) |
|
{ |
|
case 0: |
|
cb = 1; |
|
break; |
|
|
|
case 2: |
|
case 3: |
|
cb = 3; |
|
break; |
|
|
|
case 4: |
|
cb = 2; |
|
break; |
|
|
|
case 6: |
|
cb = 4; |
|
break; |
|
|
|
default: |
|
png_error(pm->this.pread, |
|
"unexpected colour type in sBIT modification"); |
|
} |
|
|
|
png_save_uint_32(pm->buffer, cb); |
|
png_save_uint_32(pm->buffer+4, CHUNK_sBIT); |
|
|
|
while (cb > 0) |
|
(pm->buffer+8)[--cb] = sbit; |
|
|
|
return 1; |
|
} |
|
else if (!add) |
|
{ |
|
/* Remove the sBIT chunk */ |
|
pm->buffer_count = pm->buffer_position = 0; |
|
return 1; |
|
} |
|
else |
|
return 0; /* do nothing */ |
|
} |
|
|
|
static void |
|
sbit_modification_init(sbit_modification *me, png_modifier *pm, png_byte sbit) |
|
{ |
|
modification_init(&me->this); |
|
me->this.chunk = CHUNK_sBIT; |
|
me->this.modify_fn = sbit_modify; |
|
me->this.add = CHUNK_PLTE; |
|
me->sbit = sbit; |
|
me->this.next = pm->modifications; |
|
pm->modifications = &me->this; |
|
} |
|
#endif /* PNG_READ_GAMMA_SUPPORTED */ |
|
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
|
|
/***************************** STANDARD PNG FILES *****************************/ |
|
/* Standard files - write and save standard files. */ |
|
/* There are two basic forms of standard images. Those which attempt to have |
|
* all the possible pixel values (not possible for 16bpp images, but a range of |
|
* values are produced) and those which have a range of image sizes. The former |
|
* are used for testing transforms, in particular gamma correction and bit |
|
* reduction and increase. The latter are reserved for testing the behavior of |
|
* libpng with respect to 'odd' image sizes - particularly small images where |
|
* rows become 1 byte and interlace passes disappear. |
|
* |
|
* The first, most useful, set are the 'transform' images, the second set of |
|
* small images are the 'size' images. |
|
* |
|
* The transform files are constructed with rows which fit into a 1024 byte row |
|
* buffer. This makes allocation easier below. Further regardless of the file |
|
* format every row has 128 pixels (giving 1024 bytes for 64bpp formats). |
|
* |
|
* Files are stored with no gAMA or sBIT chunks, with a PLTE only when needed |
|
* and with an ID derived from the colour type, bit depth and interlace type |
|
* as above (FILEID). The width (128) and height (variable) are not stored in |
|
* the FILEID - instead the fields are set to 0, indicating a transform file. |
|
* |
|
* The size files ar constructed with rows a maximum of 128 bytes wide, allowing |
|
* a maximum width of 16 pixels (for the 64bpp case.) They also have a maximum |
|
* height of 16 rows. The width and height are stored in the FILEID and, being |
|
* non-zero, indicate a size file. |
|
* |
|
* Because the PNG filter code is typically the largest CPU consumer within |
|
* libpng itself there is a tendency to attempt to optimize it. This results in |
|
* special case code which needs to be validated. To cause this to happen the |
|
* 'size' images are made to use each possible filter, in so far as this is |
|
* possible for smaller images. |
|
* |
|
* For palette image (colour type 3) multiple transform images are stored with |
|
* the same bit depth to allow testing of more colour combinations - |
|
* particularly important for testing the gamma code because libpng uses a |
|
* different code path for palette images. For size images a single palette is |
|
* used. |
|
*/ |
|
|
|
/* Make a 'standard' palette. Because there are only 256 entries in a palette |
|
* (maximum) this actually makes a random palette in the hope that enough tests |
|
* will catch enough errors. (Note that the same palette isn't produced every |
|
* time for the same test - it depends on what previous tests have been run - |
|
* but a given set of arguments to pngvalid will always produce the same palette |
|
* at the same test! This is why pseudo-random number generators are useful for |
|
* testing.) |
|
* |
|
* The store must be open for write when this is called, otherwise an internal |
|
* error will occur. This routine contains its own magic number seed, so the |
|
* palettes generated don't change if there are intervening errors (changing the |
|
* calls to the store_mark seed.) |
|
*/ |
|
static store_palette_entry * |
|
make_standard_palette(png_store* ps, int npalette, int do_tRNS) |
|
{ |
|
static png_uint_32 palette_seed[2] = { 0x87654321, 9 }; |
|
|
|
int i = 0; |
|
png_byte values[256][4]; |
|
|
|
/* Always put in black and white plus the six primary and secondary colors. |
|
*/ |
|
for (; i<8; ++i) |
|
{ |
|
values[i][1] = (png_byte)((i&1) ? 255U : 0U); |
|
values[i][2] = (png_byte)((i&2) ? 255U : 0U); |
|
values[i][3] = (png_byte)((i&4) ? 255U : 0U); |
|
} |
|
|
|
/* Then add 62 grays (one quarter of the remaining 256 slots). */ |
|
{ |
|
int j = 0; |
|
png_byte random_bytes[4]; |
|
png_byte need[256]; |
|
|
|
need[0] = 0; /*got black*/ |
|
memset(need+1, 1, (sizeof need)-2); /*need these*/ |
|
need[255] = 0; /*but not white*/ |
|
|
|
while (i<70) |
|
{ |
|
png_byte b; |
|
|
|
if (j==0) |
|
{ |
|
make_four_random_bytes(palette_seed, random_bytes); |
|
j = 4; |
|
} |
|
|
|
b = random_bytes[--j]; |
|
if (need[b]) |
|
{ |
|
values[i][1] = b; |
|
values[i][2] = b; |
|
values[i++][3] = b; |
|
} |
|
} |
|
} |
|
|
|
/* Finally add 192 colors at random - don't worry about matches to things we |
|
* already have, chance is less than 1/65536. Don't worry about grays, |
|
* chance is the same, so we get a duplicate or extra gray less than 1 time |
|
* in 170. |
|
*/ |
|
for (; i<256; ++i) |
|
make_four_random_bytes(palette_seed, values[i]); |
|
|
|
/* Fill in the alpha values in the first byte. Just use all possible values |
|
* (0..255) in an apparently random order: |
|
*/ |
|
{ |
|
store_palette_entry *palette; |
|
png_byte selector[4]; |
|
|
|
make_four_random_bytes(palette_seed, selector); |
|
|
|
if (do_tRNS) |
|
for (i=0; i<256; ++i) |
|
values[i][0] = (png_byte)(i ^ selector[0]); |
|
|
|
else |
|
for (i=0; i<256; ++i) |
|
values[i][0] = 255; /* no transparency/tRNS chunk */ |
|
|
|
/* 'values' contains 256 ARGB values, but we only need 'npalette'. |
|
* 'npalette' will always be a power of 2: 2, 4, 16 or 256. In the low |
|
* bit depth cases select colors at random, else it is difficult to have |
|
* a set of low bit depth palette test with any chance of a reasonable |
|
* range of colors. Do this by randomly permuting values into the low |
|
* 'npalette' entries using an XOR mask generated here. This also |
|
* permutes the npalette == 256 case in a potentially useful way (there is |
|
* no relationship between palette index and the color value therein!) |
|
*/ |
|
palette = store_write_palette(ps, npalette); |
|
|
|
for (i=0; i<npalette; ++i) |
|
{ |
|
palette[i].alpha = values[i ^ selector[1]][0]; |
|
palette[i].red = values[i ^ selector[1]][1]; |
|
palette[i].green = values[i ^ selector[1]][2]; |
|
palette[i].blue = values[i ^ selector[1]][3]; |
|
} |
|
|
|
return palette; |
|
} |
|
} |
|
|
|
/* Initialize a standard palette on a write stream. The 'do_tRNS' argument |
|
* indicates whether or not to also set the tRNS chunk. |
|
*/ |
|
/* TODO: the png_structp here can probably be 'const' in the future */ |
|
static void |
|
init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette, |
|
int do_tRNS) |
|
{ |
|
store_palette_entry *ppal = make_standard_palette(ps, npalette, do_tRNS); |
|
|
|
{ |
|
int i; |
|
png_color palette[256]; |
|
|
|
/* Set all entries to detect overread errors. */ |
|
for (i=0; i<npalette; ++i) |
|
{ |
|
palette[i].red = ppal[i].red; |
|
palette[i].green = ppal[i].green; |
|
palette[i].blue = ppal[i].blue; |
|
} |
|
|
|
/* Just in case fill in the rest with detectable values: */ |
|
for (; i<256; ++i) |
|
palette[i].red = palette[i].green = palette[i].blue = 42; |
|
|
|
png_set_PLTE(pp, pi, palette, npalette); |
|
} |
|
|
|
if (do_tRNS) |
|
{ |
|
int i, j; |
|
png_byte tRNS[256]; |
|
|
|
/* Set all the entries, but skip trailing opaque entries */ |
|
for (i=j=0; i<npalette; ++i) |
|
if ((tRNS[i] = ppal[i].alpha) < 255) |
|
j = i+1; |
|
|
|
/* Fill in the remainder with a detectable value: */ |
|
for (; i<256; ++i) |
|
tRNS[i] = 24; |
|
|
|
#ifdef PNG_WRITE_tRNS_SUPPORTED |
|
if (j > 0) |
|
png_set_tRNS(pp, pi, tRNS, j, 0/*color*/); |
|
#endif |
|
} |
|
} |
|
|
|
#ifdef PNG_WRITE_tRNS_SUPPORTED |
|
static void |
|
set_random_tRNS(png_structp pp, png_infop pi, png_byte colour_type, |
|
int bit_depth) |
|
{ |
|
/* To make this useful the tRNS color needs to match at least one pixel. |
|
* Random values are fine for gray, including the 16-bit case where we know |
|
* that the test image contains all the gray values. For RGB we need more |
|
* method as only 65536 different RGB values are generated. |
|
*/ |
|
png_color_16 tRNS; |
|
png_uint_16 mask = (png_uint_16)((1U << bit_depth)-1); |
|
|
|
R8(tRNS); /* makes unset fields random */ |
|
|
|
if (colour_type & 2/*RGB*/) |
|
{ |
|
if (bit_depth == 8) |
|
{ |
|
tRNS.red = random_u16(); |
|
tRNS.green = random_u16(); |
|
tRNS.blue = tRNS.red ^ tRNS.green; |
|
tRNS.red &= mask; |
|
tRNS.green &= mask; |
|
tRNS.blue &= mask; |
|
} |
|
|
|
else /* bit_depth == 16 */ |
|
{ |
|
tRNS.red = random_u16(); |
|
tRNS.green = (png_uint_16)(tRNS.red * 257); |
|
tRNS.blue = (png_uint_16)(tRNS.green * 17); |
|
} |
|
} |
|
|
|
else |
|
{ |
|
tRNS.gray = random_u16(); |
|
tRNS.gray &= mask; |
|
} |
|
|
|
png_set_tRNS(pp, pi, NULL, 0, &tRNS); |
|
} |
|
#endif |
|
|
|
/* The number of passes is related to the interlace type. There was no libpng |
|
* API to determine this prior to 1.5, so we need an inquiry function: |
|
*/ |
|
static int |
|
npasses_from_interlace_type(png_const_structp pp, int interlace_type) |
|
{ |
|
switch (interlace_type) |
|
{ |
|
default: |
|
png_error(pp, "invalid interlace type"); |
|
|
|
case PNG_INTERLACE_NONE: |
|
return 1; |
|
|
|
case PNG_INTERLACE_ADAM7: |
|
return PNG_INTERLACE_ADAM7_PASSES; |
|
} |
|
} |
|
|
|
static unsigned int |
|
bit_size(png_const_structp pp, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
switch (colour_type) |
|
{ |
|
default: png_error(pp, "invalid color type"); |
|
|
|
case 0: return bit_depth; |
|
|
|
case 2: return 3*bit_depth; |
|
|
|
case 3: return bit_depth; |
|
|
|
case 4: return 2*bit_depth; |
|
|
|
case 6: return 4*bit_depth; |
|
} |
|
} |
|
|
|
#define TRANSFORM_WIDTH 128U |
|
#define TRANSFORM_ROWMAX (TRANSFORM_WIDTH*8U) |
|
#define SIZE_ROWMAX (16*8U) /* 16 pixels, max 8 bytes each - 128 bytes */ |
|
#define STANDARD_ROWMAX TRANSFORM_ROWMAX /* The larger of the two */ |
|
#define SIZE_HEIGHTMAX 16 /* Maximum range of size images */ |
|
|
|
static size_t |
|
transform_rowsize(png_const_structp pp, png_byte colour_type, |
|
png_byte bit_depth) |
|
{ |
|
return (TRANSFORM_WIDTH * bit_size(pp, colour_type, bit_depth)) / 8; |
|
} |
|
|
|
/* transform_width(pp, colour_type, bit_depth) current returns the same number |
|
* every time, so just use a macro: |
|
*/ |
|
#define transform_width(pp, colour_type, bit_depth) TRANSFORM_WIDTH |
|
|
|
static png_uint_32 |
|
transform_height(png_const_structp pp, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
switch (bit_size(pp, colour_type, bit_depth)) |
|
{ |
|
case 1: |
|
case 2: |
|
case 4: |
|
return 1; /* Total of 128 pixels */ |
|
|
|
case 8: |
|
return 2; /* Total of 256 pixels/bytes */ |
|
|
|
case 16: |
|
return 512; /* Total of 65536 pixels */ |
|
|
|
case 24: |
|
case 32: |
|
return 512; /* 65536 pixels */ |
|
|
|
case 48: |
|
case 64: |
|
return 2048;/* 4 x 65536 pixels. */ |
|
# define TRANSFORM_HEIGHTMAX 2048 |
|
|
|
default: |
|
return 0; /* Error, will be caught later */ |
|
} |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
/* The following can only be defined here, now we have the definitions |
|
* of the transform image sizes. |
|
*/ |
|
static png_uint_32 |
|
standard_width(png_const_structp pp, png_uint_32 id) |
|
{ |
|
png_uint_32 width = WIDTH_FROM_ID(id); |
|
UNUSED(pp) |
|
|
|
if (width == 0) |
|
width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); |
|
|
|
return width; |
|
} |
|
|
|
static png_uint_32 |
|
standard_height(png_const_structp pp, png_uint_32 id) |
|
{ |
|
png_uint_32 height = HEIGHT_FROM_ID(id); |
|
|
|
if (height == 0) |
|
height = transform_height(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); |
|
|
|
return height; |
|
} |
|
|
|
static png_uint_32 |
|
standard_rowsize(png_const_structp pp, png_uint_32 id) |
|
{ |
|
png_uint_32 width = standard_width(pp, id); |
|
|
|
/* This won't overflow: */ |
|
width *= bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); |
|
return (width + 7) / 8; |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
static void |
|
transform_row(png_const_structp pp, png_byte buffer[TRANSFORM_ROWMAX], |
|
png_byte colour_type, png_byte bit_depth, png_uint_32 y) |
|
{ |
|
png_uint_32 v = y << 7; |
|
png_uint_32 i = 0; |
|
|
|
switch (bit_size(pp, colour_type, bit_depth)) |
|
{ |
|
case 1: |
|
while (i<128/8) buffer[i] = (png_byte)(v & 0xff), v += 17, ++i; |
|
return; |
|
|
|
case 2: |
|
while (i<128/4) buffer[i] = (png_byte)(v & 0xff), v += 33, ++i; |
|
return; |
|
|
|
case 4: |
|
while (i<128/2) buffer[i] = (png_byte)(v & 0xff), v += 65, ++i; |
|
return; |
|
|
|
case 8: |
|
/* 256 bytes total, 128 bytes in each row set as follows: */ |
|
while (i<128) buffer[i] = (png_byte)(v & 0xff), ++v, ++i; |
|
return; |
|
|
|
case 16: |
|
/* Generate all 65536 pixel values in order, which includes the 8 bit |
|
* GA case as well as the 16 bit G case. |
|
*/ |
|
while (i<128) |
|
{ |
|
buffer[2*i] = (png_byte)((v>>8) & 0xff); |
|
buffer[2*i+1] = (png_byte)(v & 0xff); |
|
++v; |
|
++i; |
|
} |
|
|
|
return; |
|
|
|
case 24: |
|
/* 65535 pixels, but rotate the values. */ |
|
while (i<128) |
|
{ |
|
/* Three bytes per pixel, r, g, b, make b by r^g */ |
|
buffer[3*i+0] = (png_byte)((v >> 8) & 0xff); |
|
buffer[3*i+1] = (png_byte)(v & 0xff); |
|
buffer[3*i+2] = (png_byte)(((v >> 8) ^ v) & 0xff); |
|
++v; |
|
++i; |
|
} |
|
|
|
return; |
|
|
|
case 32: |
|
/* 65535 pixels, r, g, b, a; just replicate */ |
|
while (i<128) |
|
{ |
|
buffer[4*i+0] = (png_byte)((v >> 8) & 0xff); |
|
buffer[4*i+1] = (png_byte)(v & 0xff); |
|
buffer[4*i+2] = (png_byte)((v >> 8) & 0xff); |
|
buffer[4*i+3] = (png_byte)(v & 0xff); |
|
++v; |
|
++i; |
|
} |
|
|
|
return; |
|
|
|
case 48: |
|
/* y is maximum 2047, giving 4x65536 pixels, make 'r' increase by 1 at |
|
* each pixel, g increase by 257 (0x101) and 'b' by 0x1111: |
|
*/ |
|
while (i<128) |
|
{ |
|
png_uint_32 t = v++; |
|
buffer[6*i+0] = (png_byte)((t >> 8) & 0xff); |
|
buffer[6*i+1] = (png_byte)(t & 0xff); |
|
t *= 257; |
|
buffer[6*i+2] = (png_byte)((t >> 8) & 0xff); |
|
buffer[6*i+3] = (png_byte)(t & 0xff); |
|
t *= 17; |
|
buffer[6*i+4] = (png_byte)((t >> 8) & 0xff); |
|
buffer[6*i+5] = (png_byte)(t & 0xff); |
|
++i; |
|
} |
|
|
|
return; |
|
|
|
case 64: |
|
/* As above in the 32 bit case. */ |
|
while (i<128) |
|
{ |
|
png_uint_32 t = v++; |
|
buffer[8*i+0] = (png_byte)((t >> 8) & 0xff); |
|
buffer[8*i+1] = (png_byte)(t & 0xff); |
|
buffer[8*i+4] = (png_byte)((t >> 8) & 0xff); |
|
buffer[8*i+5] = (png_byte)(t & 0xff); |
|
t *= 257; |
|
buffer[8*i+2] = (png_byte)((t >> 8) & 0xff); |
|
buffer[8*i+3] = (png_byte)(t & 0xff); |
|
buffer[8*i+6] = (png_byte)((t >> 8) & 0xff); |
|
buffer[8*i+7] = (png_byte)(t & 0xff); |
|
++i; |
|
} |
|
return; |
|
|
|
default: |
|
break; |
|
} |
|
|
|
png_error(pp, "internal error"); |
|
} |
|
|
|
/* This is just to do the right cast - could be changed to a function to check |
|
* 'bd' but there isn't much point. |
|
*/ |
|
#define DEPTH(bd) ((png_byte)(1U << (bd))) |
|
|
|
/* This is just a helper for compiling on minimal systems with no write |
|
* interlacing support. If there is no write interlacing we can't generate test |
|
* cases with interlace: |
|
*/ |
|
#ifdef PNG_WRITE_INTERLACING_SUPPORTED |
|
# define INTERLACE_LAST PNG_INTERLACE_LAST |
|
# define check_interlace_type(type) ((void)(type)) |
|
# define set_write_interlace_handling(pp,type) png_set_interlace_handling(pp) |
|
# define do_own_interlace 0 |
|
#elif PNG_LIBPNG_VER < 10700 |
|
# define set_write_interlace_handling(pp,type) (1) |
|
static void |
|
check_interlace_type(int const interlace_type) |
|
{ |
|
/* Prior to 1.7.0 libpng does not support the write of an interlaced image |
|
* unless PNG_WRITE_INTERLACING_SUPPORTED, even with do_interlace so the |
|
* code here does the pixel interlace itself, so: |
|
*/ |
|
if (interlace_type != PNG_INTERLACE_NONE) |
|
{ |
|
/* This is an internal error - --interlace tests should be skipped, not |
|
* attempted. |
|
*/ |
|
fprintf(stderr, "pngvalid: no interlace support\n"); |
|
exit(99); |
|
} |
|
} |
|
# define INTERLACE_LAST (PNG_INTERLACE_NONE+1) |
|
# define do_own_interlace 0 |
|
#else /* libpng 1.7+ */ |
|
# define set_write_interlace_handling(pp,type)\ |
|
npasses_from_interlace_type(pp,type) |
|
# define check_interlace_type(type) ((void)(type)) |
|
# define INTERLACE_LAST PNG_INTERLACE_LAST |
|
# define do_own_interlace 1 |
|
#endif /* WRITE_INTERLACING tests */ |
|
|
|
#if PNG_LIBPNG_VER >= 10700 || defined PNG_WRITE_INTERLACING_SUPPORTED |
|
# define CAN_WRITE_INTERLACE 1 |
|
#else |
|
# define CAN_WRITE_INTERLACE 0 |
|
#endif |
|
|
|
/* Do the same thing for read interlacing; this controls whether read tests do |
|
* their own de-interlace or use libpng. |
|
*/ |
|
#ifdef PNG_READ_INTERLACING_SUPPORTED |
|
# define do_read_interlace 0 |
|
#else /* no libpng read interlace support */ |
|
# define do_read_interlace 1 |
|
#endif |
|
/* The following two routines use the PNG interlace support macros from |
|
* png.h to interlace or deinterlace rows. |
|
*/ |
|
static void |
|
interlace_row(png_bytep buffer, png_const_bytep imageRow, |
|
unsigned int pixel_size, png_uint_32 w, int pass, int littleendian) |
|
{ |
|
png_uint_32 xin, xout, xstep; |
|
|
|
/* Note that this can, trivially, be optimized to a memcpy on pass 7, the |
|
* code is presented this way to make it easier to understand. In practice |
|
* consult the code in the libpng source to see other ways of doing this. |
|
* |
|
* It is OK for buffer and imageRow to be identical, because 'xin' moves |
|
* faster than 'xout' and we copy up. |
|
*/ |
|
xin = PNG_PASS_START_COL(pass); |
|
xstep = 1U<<PNG_PASS_COL_SHIFT(pass); |
|
|
|
for (xout=0; xin<w; xin+=xstep) |
|
{ |
|
pixel_copy(buffer, xout, imageRow, xin, pixel_size, littleendian); |
|
++xout; |
|
} |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
static void |
|
deinterlace_row(png_bytep buffer, png_const_bytep row, |
|
unsigned int pixel_size, png_uint_32 w, int pass, int littleendian) |
|
{ |
|
/* The inverse of the above, 'row' is part of row 'y' of the output image, |
|
* in 'buffer'. The image is 'w' wide and this is pass 'pass', distribute |
|
* the pixels of row into buffer and return the number written (to allow |
|
* this to be checked). |
|
*/ |
|
png_uint_32 xin, xout, xstep; |
|
|
|
xout = PNG_PASS_START_COL(pass); |
|
xstep = 1U<<PNG_PASS_COL_SHIFT(pass); |
|
|
|
for (xin=0; xout<w; xout+=xstep) |
|
{ |
|
pixel_copy(buffer, xout, row, xin, pixel_size, littleendian); |
|
++xin; |
|
} |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* Make a standardized image given an image colour type, bit depth and |
|
* interlace type. The standard images have a very restricted range of |
|
* rows and heights and are used for testing transforms rather than image |
|
* layout details. See make_size_images below for a way to make images |
|
* that test odd sizes along with the libpng interlace handling. |
|
*/ |
|
#ifdef PNG_WRITE_FILTER_SUPPORTED |
|
static void |
|
choose_random_filter(png_structp pp, int start) |
|
{ |
|
/* Choose filters randomly except that on the very first row ensure that |
|
* there is at least one previous row filter. |
|
*/ |
|
int filters = PNG_ALL_FILTERS & random_mod(256U); |
|
|
|
/* There may be no filters; skip the setting. */ |
|
if (filters != 0) |
|
{ |
|
if (start && filters < PNG_FILTER_UP) |
|
filters |= PNG_FILTER_UP; |
|
|
|
png_set_filter(pp, 0/*method*/, filters); |
|
} |
|
} |
|
#else /* !WRITE_FILTER */ |
|
# define choose_random_filter(pp, start) ((void)0) |
|
#endif /* !WRITE_FILTER */ |
|
|
|
static void |
|
make_transform_image(png_store* const ps, png_byte const colour_type, |
|
png_byte const bit_depth, unsigned int palette_number, |
|
int interlace_type, png_const_charp name) |
|
{ |
|
context(ps, fault); |
|
|
|
check_interlace_type(interlace_type); |
|
|
|
Try |
|
{ |
|
png_infop pi; |
|
png_structp pp = set_store_for_write(ps, &pi, name); |
|
png_uint_32 h, w; |
|
|
|
/* In the event of a problem return control to the Catch statement below |
|
* to do the clean up - it is not possible to 'return' directly from a Try |
|
* block. |
|
*/ |
|
if (pp == NULL) |
|
Throw ps; |
|
|
|
w = transform_width(pp, colour_type, bit_depth); |
|
h = transform_height(pp, colour_type, bit_depth); |
|
|
|
png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, |
|
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); |
|
|
|
#ifdef PNG_TEXT_SUPPORTED |
|
# if defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED) |
|
# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_zTXt |
|
# else |
|
# define TEXT_COMPRESSION PNG_TEXT_COMPRESSION_NONE |
|
# endif |
|
{ |
|
static char key[] = "image name"; /* must be writeable */ |
|
size_t pos; |
|
png_text text; |
|
char copy[FILE_NAME_SIZE]; |
|
|
|
/* Use a compressed text string to test the correct interaction of text |
|
* compression and IDAT compression. |
|
*/ |
|
text.compression = TEXT_COMPRESSION; |
|
text.key = key; |
|
/* Yuck: the text must be writable! */ |
|
pos = safecat(copy, sizeof copy, 0, ps->wname); |
|
text.text = copy; |
|
text.text_length = pos; |
|
text.itxt_length = 0; |
|
text.lang = 0; |
|
text.lang_key = 0; |
|
|
|
png_set_text(pp, pi, &text, 1); |
|
} |
|
#endif |
|
|
|
if (colour_type == 3) /* palette */ |
|
init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/); |
|
|
|
# ifdef PNG_WRITE_tRNS_SUPPORTED |
|
else if (palette_number) |
|
set_random_tRNS(pp, pi, colour_type, bit_depth); |
|
# endif |
|
|
|
png_write_info(pp, pi); |
|
|
|
if (png_get_rowbytes(pp, pi) != |
|
transform_rowsize(pp, colour_type, bit_depth)) |
|
png_error(pp, "transform row size incorrect"); |
|
|
|
else |
|
{ |
|
/* Somewhat confusingly this must be called *after* png_write_info |
|
* because if it is called before, the information in *pp has not been |
|
* updated to reflect the interlaced image. |
|
*/ |
|
int npasses = set_write_interlace_handling(pp, interlace_type); |
|
int pass; |
|
|
|
if (npasses != npasses_from_interlace_type(pp, interlace_type)) |
|
png_error(pp, "write: png_set_interlace_handling failed"); |
|
|
|
for (pass=0; pass<npasses; ++pass) |
|
{ |
|
png_uint_32 y; |
|
|
|
/* do_own_interlace is a pre-defined boolean (a #define) which is |
|
* set if we have to work out the interlaced rows here. |
|
*/ |
|
for (y=0; y<h; ++y) |
|
{ |
|
png_byte buffer[TRANSFORM_ROWMAX]; |
|
|
|
transform_row(pp, buffer, colour_type, bit_depth, y); |
|
|
|
# if do_own_interlace |
|
/* If do_own_interlace *and* the image is interlaced we need a |
|
* reduced interlace row; this may be reduced to empty. |
|
*/ |
|
if (interlace_type == PNG_INTERLACE_ADAM7) |
|
{ |
|
/* The row must not be written if it doesn't exist, notice |
|
* that there are two conditions here, either the row isn't |
|
* ever in the pass or the row would be but isn't wide |
|
* enough to contribute any pixels. In fact the wPass test |
|
* can be used to skip the whole y loop in this case. |
|
*/ |
|
if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && |
|
PNG_PASS_COLS(w, pass) > 0) |
|
interlace_row(buffer, buffer, |
|
bit_size(pp, colour_type, bit_depth), w, pass, |
|
0/*data always bigendian*/); |
|
else |
|
continue; |
|
} |
|
# endif /* do_own_interlace */ |
|
|
|
choose_random_filter(pp, pass == 0 && y == 0); |
|
png_write_row(pp, buffer); |
|
} |
|
} |
|
} |
|
|
|
#ifdef PNG_TEXT_SUPPORTED |
|
{ |
|
static char key[] = "end marker"; |
|
static char comment[] = "end"; |
|
png_text text; |
|
|
|
/* Use a compressed text string to test the correct interaction of text |
|
* compression and IDAT compression. |
|
*/ |
|
text.compression = TEXT_COMPRESSION; |
|
text.key = key; |
|
text.text = comment; |
|
text.text_length = (sizeof comment)-1; |
|
text.itxt_length = 0; |
|
text.lang = 0; |
|
text.lang_key = 0; |
|
|
|
png_set_text(pp, pi, &text, 1); |
|
} |
|
#endif |
|
|
|
png_write_end(pp, pi); |
|
|
|
/* And store this under the appropriate id, then clean up. */ |
|
store_storefile(ps, FILEID(colour_type, bit_depth, palette_number, |
|
interlace_type, 0, 0, 0)); |
|
|
|
store_write_reset(ps); |
|
} |
|
|
|
Catch(fault) |
|
{ |
|
/* Use the png_store returned by the exception. This may help the compiler |
|
* because 'ps' is not used in this branch of the setjmp. Note that fault |
|
* and ps will always be the same value. |
|
*/ |
|
store_write_reset(fault); |
|
} |
|
} |
|
|
|
static void |
|
make_transform_images(png_modifier *pm) |
|
{ |
|
png_byte colour_type = 0; |
|
png_byte bit_depth = 0; |
|
unsigned int palette_number = 0; |
|
|
|
/* This is in case of errors. */ |
|
safecat(pm->this.test, sizeof pm->this.test, 0, "make standard images"); |
|
|
|
/* Use next_format to enumerate all the combinations we test, including |
|
* generating multiple low bit depth palette images. Non-A images (palette |
|
* and direct) are created with and without tRNS chunks. |
|
*/ |
|
while (next_format(&colour_type, &bit_depth, &palette_number, 1, 1)) |
|
{ |
|
int interlace_type; |
|
|
|
for (interlace_type = PNG_INTERLACE_NONE; |
|
interlace_type < INTERLACE_LAST; ++interlace_type) |
|
{ |
|
char name[FILE_NAME_SIZE]; |
|
|
|
standard_name(name, sizeof name, 0, colour_type, bit_depth, |
|
palette_number, interlace_type, 0, 0, do_own_interlace); |
|
make_transform_image(&pm->this, colour_type, bit_depth, palette_number, |
|
interlace_type, name); |
|
} |
|
} |
|
} |
|
|
|
/* Build a single row for the 'size' test images; this fills in only the |
|
* first bit_width bits of the sample row. |
|
*/ |
|
static void |
|
size_row(png_byte buffer[SIZE_ROWMAX], png_uint_32 bit_width, png_uint_32 y) |
|
{ |
|
/* height is in the range 1 to 16, so: */ |
|
y = ((y & 1) << 7) + ((y & 2) << 6) + ((y & 4) << 5) + ((y & 8) << 4); |
|
/* the following ensures bits are set in small images: */ |
|
y ^= 0xA5; |
|
|
|
while (bit_width >= 8) |
|
*buffer++ = (png_byte)y++, bit_width -= 8; |
|
|
|
/* There may be up to 7 remaining bits, these go in the most significant |
|
* bits of the byte. |
|
*/ |
|
if (bit_width > 0) |
|
{ |
|
png_uint_32 mask = (1U<<(8-bit_width))-1; |
|
*buffer = (png_byte)((*buffer & mask) | (y & ~mask)); |
|
} |
|
} |
|
|
|
static void |
|
make_size_image(png_store* const ps, png_byte const colour_type, |
|
png_byte const bit_depth, int const interlace_type, |
|
png_uint_32 const w, png_uint_32 const h, |
|
int const do_interlace) |
|
{ |
|
context(ps, fault); |
|
|
|
check_interlace_type(interlace_type); |
|
|
|
Try |
|
{ |
|
png_infop pi; |
|
png_structp pp; |
|
unsigned int pixel_size; |
|
|
|
/* Make a name and get an appropriate id for the store: */ |
|
char name[FILE_NAME_SIZE]; |
|
png_uint_32 id = FILEID(colour_type, bit_depth, 0/*palette*/, |
|
interlace_type, w, h, do_interlace); |
|
|
|
standard_name_from_id(name, sizeof name, 0, id); |
|
pp = set_store_for_write(ps, &pi, name); |
|
|
|
/* In the event of a problem return control to the Catch statement below |
|
* to do the clean up - it is not possible to 'return' directly from a Try |
|
* block. |
|
*/ |
|
if (pp == NULL) |
|
Throw ps; |
|
|
|
png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, |
|
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); |
|
|
|
#ifdef PNG_TEXT_SUPPORTED |
|
{ |
|
static char key[] = "image name"; /* must be writeable */ |
|
size_t pos; |
|
png_text text; |
|
char copy[FILE_NAME_SIZE]; |
|
|
|
/* Use a compressed text string to test the correct interaction of text |
|
* compression and IDAT compression. |
|
*/ |
|
text.compression = TEXT_COMPRESSION; |
|
text.key = key; |
|
/* Yuck: the text must be writable! */ |
|
pos = safecat(copy, sizeof copy, 0, ps->wname); |
|
text.text = copy; |
|
text.text_length = pos; |
|
text.itxt_length = 0; |
|
text.lang = 0; |
|
text.lang_key = 0; |
|
|
|
png_set_text(pp, pi, &text, 1); |
|
} |
|
#endif |
|
|
|
if (colour_type == 3) /* palette */ |
|
init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); |
|
|
|
png_write_info(pp, pi); |
|
|
|
/* Calculate the bit size, divide by 8 to get the byte size - this won't |
|
* overflow because we know the w values are all small enough even for |
|
* a system where 'unsigned int' is only 16 bits. |
|
*/ |
|
pixel_size = bit_size(pp, colour_type, bit_depth); |
|
if (png_get_rowbytes(pp, pi) != ((w * pixel_size) + 7) / 8) |
|
png_error(pp, "size row size incorrect"); |
|
|
|
else |
|
{ |
|
int npasses = npasses_from_interlace_type(pp, interlace_type); |
|
png_uint_32 y; |
|
int pass; |
|
png_byte image[16][SIZE_ROWMAX]; |
|
|
|
/* To help consistent error detection make the parts of this buffer |
|
* that aren't set below all '1': |
|
*/ |
|
memset(image, 0xff, sizeof image); |
|
|
|
if (!do_interlace && |
|
npasses != set_write_interlace_handling(pp, interlace_type)) |
|
png_error(pp, "write: png_set_interlace_handling failed"); |
|
|
|
/* Prepare the whole image first to avoid making it 7 times: */ |
|
for (y=0; y<h; ++y) |
|
size_row(image[y], w * pixel_size, y); |
|
|
|
for (pass=0; pass<npasses; ++pass) |
|
{ |
|
/* The following two are for checking the macros: */ |
|
png_uint_32 wPass = PNG_PASS_COLS(w, pass); |
|
|
|
/* If do_interlace is set we don't call png_write_row for every |
|
* row because some of them are empty. In fact, for a 1x1 image, |
|
* most of them are empty! |
|
*/ |
|
for (y=0; y<h; ++y) |
|
{ |
|
png_const_bytep row = image[y]; |
|
png_byte tempRow[SIZE_ROWMAX]; |
|
|
|
/* If do_interlace *and* the image is interlaced we |
|
* need a reduced interlace row; this may be reduced |
|
* to empty. |
|
*/ |
|
if (do_interlace && interlace_type == PNG_INTERLACE_ADAM7) |
|
{ |
|
/* The row must not be written if it doesn't exist, notice |
|
* that there are two conditions here, either the row isn't |
|
* ever in the pass or the row would be but isn't wide |
|
* enough to contribute any pixels. In fact the wPass test |
|
* can be used to skip the whole y loop in this case. |
|
*/ |
|
if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && wPass > 0) |
|
{ |
|
/* Set to all 1's for error detection (libpng tends to |
|
* set unset things to 0). |
|
*/ |
|
memset(tempRow, 0xff, sizeof tempRow); |
|
interlace_row(tempRow, row, pixel_size, w, pass, |
|
0/*data always bigendian*/); |
|
row = tempRow; |
|
} |
|
else |
|
continue; |
|
} |
|
|
|
# ifdef PNG_WRITE_FILTER_SUPPORTED |
|
/* Only get to here if the row has some pixels in it, set the |
|
* filters to 'all' for the very first row and thereafter to a |
|
* single filter. It isn't well documented, but png_set_filter |
|
* does accept a filter number (per the spec) as well as a bit |
|
* mask. |
|
* |
|
* The code now uses filters at random, except that on the first |
|
* row of an image it ensures that a previous row filter is in |
|
* the set so that libpng allocates the row buffer. |
|
*/ |
|
{ |
|
int filters = 8 << random_mod(PNG_FILTER_VALUE_LAST); |
|
|
|
if (pass == 0 && y == 0 && |
|
(filters < PNG_FILTER_UP || w == 1U)) |
|
filters |= PNG_FILTER_UP; |
|
|
|
png_set_filter(pp, 0/*method*/, filters); |
|
} |
|
# endif |
|
|
|
png_write_row(pp, row); |
|
} |
|
} |
|
} |
|
|
|
#ifdef PNG_TEXT_SUPPORTED |
|
{ |
|
static char key[] = "end marker"; |
|
static char comment[] = "end"; |
|
png_text text; |
|
|
|
/* Use a compressed text string to test the correct interaction of text |
|
* compression and IDAT compression. |
|
*/ |
|
text.compression = TEXT_COMPRESSION; |
|
text.key = key; |
|
text.text = comment; |
|
text.text_length = (sizeof comment)-1; |
|
text.itxt_length = 0; |
|
text.lang = 0; |
|
text.lang_key = 0; |
|
|
|
png_set_text(pp, pi, &text, 1); |
|
} |
|
#endif |
|
|
|
png_write_end(pp, pi); |
|
|
|
/* And store this under the appropriate id, then clean up. */ |
|
store_storefile(ps, id); |
|
|
|
store_write_reset(ps); |
|
} |
|
|
|
Catch(fault) |
|
{ |
|
/* Use the png_store returned by the exception. This may help the compiler |
|
* because 'ps' is not used in this branch of the setjmp. Note that fault |
|
* and ps will always be the same value. |
|
*/ |
|
store_write_reset(fault); |
|
} |
|
} |
|
|
|
static void |
|
make_size(png_store* const ps, png_byte const colour_type, int bdlo, |
|
int const bdhi) |
|
{ |
|
for (; bdlo <= bdhi; ++bdlo) |
|
{ |
|
png_uint_32 width; |
|
|
|
for (width = 1; width <= 16; ++width) |
|
{ |
|
png_uint_32 height; |
|
|
|
for (height = 1; height <= 16; ++height) |
|
{ |
|
/* The four combinations of DIY interlace and interlace or not - |
|
* no interlace + DIY should be identical to no interlace with |
|
* libpng doing it. |
|
*/ |
|
make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, |
|
width, height, 0); |
|
make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_NONE, |
|
width, height, 1); |
|
# ifdef PNG_WRITE_INTERLACING_SUPPORTED |
|
make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, |
|
width, height, 0); |
|
# endif |
|
# if CAN_WRITE_INTERLACE |
|
/* 1.7.0 removes the hack that prevented app write of an interlaced |
|
* image if WRITE_INTERLACE was not supported |
|
*/ |
|
make_size_image(ps, colour_type, DEPTH(bdlo), PNG_INTERLACE_ADAM7, |
|
width, height, 1); |
|
# endif |
|
} |
|
} |
|
} |
|
} |
|
|
|
static void |
|
make_size_images(png_store *ps) |
|
{ |
|
/* This is in case of errors. */ |
|
safecat(ps->test, sizeof ps->test, 0, "make size images"); |
|
|
|
/* Arguments are colour_type, low bit depth, high bit depth |
|
*/ |
|
make_size(ps, 0, 0, WRITE_BDHI); |
|
make_size(ps, 2, 3, WRITE_BDHI); |
|
make_size(ps, 3, 0, 3 /*palette: max 8 bits*/); |
|
make_size(ps, 4, 3, WRITE_BDHI); |
|
make_size(ps, 6, 3, WRITE_BDHI); |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
/* Return a row based on image id and 'y' for checking: */ |
|
static void |
|
standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX], |
|
png_uint_32 id, png_uint_32 y) |
|
{ |
|
if (WIDTH_FROM_ID(id) == 0) |
|
transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); |
|
else |
|
size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), |
|
DEPTH_FROM_ID(id)), y); |
|
} |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* Tests - individual test cases */ |
|
/* Like 'make_standard' but errors are deliberately introduced into the calls |
|
* to ensure that they get detected - it should not be possible to write an |
|
* invalid image with libpng! |
|
*/ |
|
/* TODO: the 'set' functions can probably all be made to take a |
|
* png_const_structp rather than a modifiable one. |
|
*/ |
|
#ifdef PNG_WARNINGS_SUPPORTED |
|
static void |
|
sBIT0_error_fn(png_structp pp, png_infop pi) |
|
{ |
|
/* 0 is invalid... */ |
|
png_color_8 bad; |
|
bad.red = bad.green = bad.blue = bad.gray = bad.alpha = 0; |
|
png_set_sBIT(pp, pi, &bad); |
|
} |
|
|
|
static void |
|
sBIT_error_fn(png_structp pp, png_infop pi) |
|
{ |
|
png_byte bit_depth; |
|
png_color_8 bad; |
|
|
|
if (png_get_color_type(pp, pi) == PNG_COLOR_TYPE_PALETTE) |
|
bit_depth = 8; |
|
|
|
else |
|
bit_depth = png_get_bit_depth(pp, pi); |
|
|
|
/* Now we know the bit depth we can easily generate an invalid sBIT entry */ |
|
bad.red = bad.green = bad.blue = bad.gray = bad.alpha = |
|
(png_byte)(bit_depth+1); |
|
png_set_sBIT(pp, pi, &bad); |
|
} |
|
|
|
static const struct |
|
{ |
|
void (*fn)(png_structp, png_infop); |
|
const char *msg; |
|
unsigned int warning :1; /* the error is a warning... */ |
|
} error_test[] = |
|
{ |
|
/* no warnings makes these errors undetectable prior to 1.7.0 */ |
|
{ sBIT0_error_fn, "sBIT(0): failed to detect error", |
|
PNG_LIBPNG_VER < 10700 }, |
|
|
|
{ sBIT_error_fn, "sBIT(too big): failed to detect error", |
|
PNG_LIBPNG_VER < 10700 }, |
|
}; |
|
|
|
static void |
|
make_error(png_store* const ps, png_byte const colour_type, |
|
png_byte bit_depth, int interlace_type, int test, png_const_charp name) |
|
{ |
|
context(ps, fault); |
|
|
|
check_interlace_type(interlace_type); |
|
|
|
Try |
|
{ |
|
png_infop pi; |
|
png_structp pp = set_store_for_write(ps, &pi, name); |
|
png_uint_32 w, h; |
|
gnu_volatile(pp) |
|
|
|
if (pp == NULL) |
|
Throw ps; |
|
|
|
w = transform_width(pp, colour_type, bit_depth); |
|
gnu_volatile(w) |
|
h = transform_height(pp, colour_type, bit_depth); |
|
gnu_volatile(h) |
|
png_set_IHDR(pp, pi, w, h, bit_depth, colour_type, interlace_type, |
|
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); |
|
|
|
if (colour_type == 3) /* palette */ |
|
init_standard_palette(ps, pp, pi, 1U << bit_depth, 0/*do tRNS*/); |
|
|
|
/* Time for a few errors; these are in various optional chunks, the |
|
* standard tests test the standard chunks pretty well. |
|
*/ |
|
# define exception__prev exception_prev_1 |
|
# define exception__env exception_env_1 |
|
Try |
|
{ |
|
gnu_volatile(exception__prev) |
|
|
|
/* Expect this to throw: */ |
|
ps->expect_error = !error_test[test].warning; |
|
ps->expect_warning = error_test[test].warning; |
|
ps->saw_warning = 0; |
|
error_test[test].fn(pp, pi); |
|
|
|
/* Normally the error is only detected here: */ |
|
png_write_info(pp, pi); |
|
|
|
/* And handle the case where it was only a warning: */ |
|
if (ps->expect_warning && ps->saw_warning) |
|
Throw ps; |
|
|
|
/* If we get here there is a problem, we have success - no error or |
|
* no warning - when we shouldn't have success. Log an error. |
|
*/ |
|
store_log(ps, pp, error_test[test].msg, 1 /*error*/); |
|
} |
|
|
|
Catch (fault) |
|
{ /* expected exit */ |
|
} |
|
#undef exception__prev |
|
#undef exception__env |
|
|
|
/* And clear these flags */ |
|
ps->expect_warning = 0; |
|
|
|
if (ps->expect_error) |
|
ps->expect_error = 0; |
|
|
|
else |
|
{ |
|
/* Now write the whole image, just to make sure that the detected, or |
|
* undetected, error has not created problems inside libpng. This |
|
* doesn't work if there was a png_error in png_write_info because that |
|
* can abort before PLTE was written. |
|
*/ |
|
if (png_get_rowbytes(pp, pi) != |
|
transform_rowsize(pp, colour_type, bit_depth)) |
|
png_error(pp, "row size incorrect"); |
|
|
|
else |
|
{ |
|
int npasses = set_write_interlace_handling(pp, interlace_type); |
|
int pass; |
|
|
|
if (npasses != npasses_from_interlace_type(pp, interlace_type)) |
|
png_error(pp, "write: png_set_interlace_handling failed"); |
|
|
|
for (pass=0; pass<npasses; ++pass) |
|
{ |
|
png_uint_32 y; |
|
|
|
for (y=0; y<h; ++y) |
|
{ |
|
png_byte buffer[TRANSFORM_ROWMAX]; |
|
|
|
transform_row(pp, buffer, colour_type, bit_depth, y); |
|
|
|
# if do_own_interlace |
|
/* If do_own_interlace *and* the image is interlaced we |
|
* need a reduced interlace row; this may be reduced to |
|
* empty. |
|
*/ |
|
if (interlace_type == PNG_INTERLACE_ADAM7) |
|
{ |
|
/* The row must not be written if it doesn't exist, |
|
* notice that there are two conditions here, either the |
|
* row isn't ever in the pass or the row would be but |
|
* isn't wide enough to contribute any pixels. In fact |
|
* the wPass test can be used to skip the whole y loop |
|
* in this case. |
|
*/ |
|
if (PNG_ROW_IN_INTERLACE_PASS(y, pass) && |
|
PNG_PASS_COLS(w, pass) > 0) |
|
interlace_row(buffer, buffer, |
|
bit_size(pp, colour_type, bit_depth), w, pass, |
|
0/*data always bigendian*/); |
|
else |
|
continue; |
|
} |
|
# endif /* do_own_interlace */ |
|
|
|
png_write_row(pp, buffer); |
|
} |
|
} |
|
} /* image writing */ |
|
|
|
png_write_end(pp, pi); |
|
} |
|
|
|
/* The following deletes the file that was just written. */ |
|
store_write_reset(ps); |
|
} |
|
|
|
Catch(fault) |
|
{ |
|
store_write_reset(fault); |
|
} |
|
} |
|
|
|
static int |
|
make_errors(png_modifier* const pm, png_byte const colour_type, |
|
int bdlo, int const bdhi) |
|
{ |
|
for (; bdlo <= bdhi; ++bdlo) |
|
{ |
|
int interlace_type; |
|
|
|
for (interlace_type = PNG_INTERLACE_NONE; |
|
interlace_type < INTERLACE_LAST; ++interlace_type) |
|
{ |
|
unsigned int test; |
|
char name[FILE_NAME_SIZE]; |
|
|
|
standard_name(name, sizeof name, 0, colour_type, 1<<bdlo, 0, |
|
interlace_type, 0, 0, do_own_interlace); |
|
|
|
for (test=0; test<ARRAY_SIZE(error_test); ++test) |
|
{ |
|
make_error(&pm->this, colour_type, DEPTH(bdlo), interlace_type, |
|
test, name); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
} |
|
} |
|
} |
|
|
|
return 1; /* keep going */ |
|
} |
|
#endif /* PNG_WARNINGS_SUPPORTED */ |
|
|
|
static void |
|
perform_error_test(png_modifier *pm) |
|
{ |
|
#ifdef PNG_WARNINGS_SUPPORTED /* else there are no cases that work! */ |
|
/* Need to do this here because we just write in this test. */ |
|
safecat(pm->this.test, sizeof pm->this.test, 0, "error test"); |
|
|
|
if (!make_errors(pm, 0, 0, WRITE_BDHI)) |
|
return; |
|
|
|
if (!make_errors(pm, 2, 3, WRITE_BDHI)) |
|
return; |
|
|
|
if (!make_errors(pm, 3, 0, 3)) |
|
return; |
|
|
|
if (!make_errors(pm, 4, 3, WRITE_BDHI)) |
|
return; |
|
|
|
if (!make_errors(pm, 6, 3, WRITE_BDHI)) |
|
return; |
|
#else |
|
UNUSED(pm) |
|
#endif |
|
} |
|
|
|
/* This is just to validate the internal PNG formatting code - if this fails |
|
* then the warning messages the library outputs will probably be garbage. |
|
*/ |
|
static void |
|
perform_formatting_test(png_store *ps) |
|
{ |
|
#ifdef PNG_TIME_RFC1123_SUPPORTED |
|
/* The handle into the formatting code is the RFC1123 support; this test does |
|
* nothing if that is compiled out. |
|
*/ |
|
context(ps, fault); |
|
|
|
Try |
|
{ |
|
png_const_charp correct = "29 Aug 2079 13:53:60 +0000"; |
|
png_const_charp result; |
|
# if PNG_LIBPNG_VER >= 10600 |
|
char timestring[29]; |
|
# endif |
|
png_structp pp; |
|
png_time pt; |
|
|
|
pp = set_store_for_write(ps, NULL, "libpng formatting test"); |
|
|
|
if (pp == NULL) |
|
Throw ps; |
|
|
|
|
|
/* Arbitrary settings: */ |
|
pt.year = 2079; |
|
pt.month = 8; |
|
pt.day = 29; |
|
pt.hour = 13; |
|
pt.minute = 53; |
|
pt.second = 60; /* a leap second */ |
|
|
|
# if PNG_LIBPNG_VER < 10600 |
|
result = png_convert_to_rfc1123(pp, &pt); |
|
# else |
|
if (png_convert_to_rfc1123_buffer(timestring, &pt)) |
|
result = timestring; |
|
|
|
else |
|
result = NULL; |
|
# endif |
|
|
|
if (result == NULL) |
|
png_error(pp, "png_convert_to_rfc1123 failed"); |
|
|
|
if (strcmp(result, correct) != 0) |
|
{ |
|
size_t pos = 0; |
|
char msg[128]; |
|
|
|
pos = safecat(msg, sizeof msg, pos, "png_convert_to_rfc1123("); |
|
pos = safecat(msg, sizeof msg, pos, correct); |
|
pos = safecat(msg, sizeof msg, pos, ") returned: '"); |
|
pos = safecat(msg, sizeof msg, pos, result); |
|
pos = safecat(msg, sizeof msg, pos, "'"); |
|
|
|
png_error(pp, msg); |
|
} |
|
|
|
store_write_reset(ps); |
|
} |
|
|
|
Catch(fault) |
|
{ |
|
store_write_reset(fault); |
|
} |
|
#else |
|
UNUSED(ps) |
|
#endif |
|
} |
|
|
|
#ifdef PNG_READ_SUPPORTED |
|
/* Because we want to use the same code in both the progressive reader and the |
|
* sequential reader it is necessary to deal with the fact that the progressive |
|
* reader callbacks only have one parameter (png_get_progressive_ptr()), so this |
|
* must contain all the test parameters and all the local variables directly |
|
* accessible to the sequential reader implementation. |
|
* |
|
* The technique adopted is to reinvent part of what Dijkstra termed a |
|
* 'display'; an array of pointers to the stack frames of enclosing functions so |
|
* that a nested function definition can access the local (C auto) variables of |
|
* the functions that contain its definition. In fact C provides the first |
|
* pointer (the local variables - the stack frame pointer) and the last (the |
|
* global variables - the BCPL global vector typically implemented as global |
|
* addresses), this code requires one more pointer to make the display - the |
|
* local variables (and function call parameters) of the function that actually |
|
* invokes either the progressive or sequential reader. |
|
* |
|
* Perhaps confusingly this technique is confounded with classes - the |
|
* 'standard_display' defined here is sub-classed as the 'gamma_display' below. |
|
* A gamma_display is a standard_display, taking advantage of the ANSI-C |
|
* requirement that the pointer to the first member of a structure must be the |
|
* same as the pointer to the structure. This allows us to reuse standard_ |
|
* functions in the gamma test code; something that could not be done with |
|
* nested functions! |
|
*/ |
|
typedef struct standard_display |
|
{ |
|
png_store* ps; /* Test parameters (passed to the function) */ |
|
png_byte colour_type; |
|
png_byte bit_depth; |
|
png_byte red_sBIT; /* Input data sBIT values. */ |
|
png_byte green_sBIT; |
|
png_byte blue_sBIT; |
|
png_byte alpha_sBIT; |
|
png_byte interlace_type; |
|
png_byte filler; /* Output has a filler */ |
|
png_uint_32 id; /* Calculated file ID */ |
|
png_uint_32 w; /* Width of image */ |
|
png_uint_32 h; /* Height of image */ |
|
int npasses; /* Number of interlaced passes */ |
|
png_uint_32 pixel_size; /* Width of one pixel in bits */ |
|
png_uint_32 bit_width; /* Width of output row in bits */ |
|
size_t cbRow; /* Bytes in a row of the output image */ |
|
int do_interlace; /* Do interlacing internally */ |
|
int littleendian; /* App (row) data is little endian */ |
|
int is_transparent; /* Transparency information was present. */ |
|
int has_tRNS; /* color type GRAY or RGB with a tRNS chunk. */ |
|
int speed; /* Doing a speed test */ |
|
int use_update_info;/* Call update_info, not start_image */ |
|
struct |
|
{ |
|
png_uint_16 red; |
|
png_uint_16 green; |
|
png_uint_16 blue; |
|
} transparent; /* The transparent color, if set. */ |
|
int npalette; /* Number of entries in the palette. */ |
|
store_palette |
|
palette; |
|
} standard_display; |
|
|
|
static void |
|
standard_display_init(standard_display *dp, png_store* ps, png_uint_32 id, |
|
int do_interlace, int use_update_info) |
|
{ |
|
memset(dp, 0, sizeof *dp); |
|
|
|
dp->ps = ps; |
|
dp->colour_type = COL_FROM_ID(id); |
|
dp->bit_depth = DEPTH_FROM_ID(id); |
|
if (dp->bit_depth < 1 || dp->bit_depth > 16) |
|
internal_error(ps, "internal: bad bit depth"); |
|
if (dp->colour_type == 3) |
|
dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = 8; |
|
else |
|
dp->red_sBIT = dp->blue_sBIT = dp->green_sBIT = dp->alpha_sBIT = |
|
dp->bit_depth; |
|
dp->interlace_type = INTERLACE_FROM_ID(id); |
|
check_interlace_type(dp->interlace_type); |
|
dp->id = id; |
|
/* All the rest are filled in after the read_info: */ |
|
dp->w = 0; |
|
dp->h = 0; |
|
dp->npasses = 0; |
|
dp->pixel_size = 0; |
|
dp->bit_width = 0; |
|
dp->cbRow = 0; |
|
dp->do_interlace = do_interlace; |
|
dp->littleendian = 0; |
|
dp->is_transparent = 0; |
|
dp->speed = ps->speed; |
|
dp->use_update_info = use_update_info; |
|
dp->npalette = 0; |
|
/* Preset the transparent color to black: */ |
|
memset(&dp->transparent, 0, sizeof dp->transparent); |
|
/* Preset the palette to full intensity/opaque throughout: */ |
|
memset(dp->palette, 0xff, sizeof dp->palette); |
|
} |
|
|
|
/* Initialize the palette fields - this must be done later because the palette |
|
* comes from the particular png_store_file that is selected. |
|
*/ |
|
static void |
|
standard_palette_init(standard_display *dp) |
|
{ |
|
store_palette_entry *palette = store_current_palette(dp->ps, &dp->npalette); |
|
|
|
/* The remaining entries remain white/opaque. */ |
|
if (dp->npalette > 0) |
|
{ |
|
int i = dp->npalette; |
|
memcpy(dp->palette, palette, i * sizeof *palette); |
|
|
|
/* Check for a non-opaque palette entry: */ |
|
while (--i >= 0) |
|
if (palette[i].alpha < 255) |
|
break; |
|
|
|
# ifdef __GNUC__ |
|
/* GCC can't handle the more obviously optimizable version. */ |
|
if (i >= 0) |
|
dp->is_transparent = 1; |
|
else |
|
dp->is_transparent = 0; |
|
# else |
|
dp->is_transparent = (i >= 0); |
|
# endif |
|
} |
|
} |
|
|
|
/* Utility to read the palette from the PNG file and convert it into |
|
* store_palette format. This returns 1 if there is any transparency in the |
|
* palette (it does not check for a transparent colour in the non-palette case.) |
|
*/ |
|
static int |
|
read_palette(store_palette palette, int *npalette, png_const_structp pp, |
|
png_infop pi) |
|
{ |
|
png_colorp pal; |
|
png_bytep trans_alpha; |
|
int num; |
|
|
|
pal = 0; |
|
*npalette = -1; |
|
|
|
if (png_get_PLTE(pp, pi, &pal, npalette) & PNG_INFO_PLTE) |
|
{ |
|
int i = *npalette; |
|
|
|
if (i <= 0 || i > 256) |
|
png_error(pp, "validate: invalid PLTE count"); |
|
|
|
while (--i >= 0) |
|
{ |
|
palette[i].red = pal[i].red; |
|
palette[i].green = pal[i].green; |
|
palette[i].blue = pal[i].blue; |
|
} |
|
|
|
/* Mark the remainder of the entries with a flag value (other than |
|
* white/opaque which is the flag value stored above.) |
|
*/ |
|
memset(palette + *npalette, 126, (256-*npalette) * sizeof *palette); |
|
} |
|
|
|
else /* !png_get_PLTE */ |
|
{ |
|
if (*npalette != (-1)) |
|
png_error(pp, "validate: invalid PLTE result"); |
|
/* But there is no palette, so record this: */ |
|
*npalette = 0; |
|
memset(palette, 113, sizeof (store_palette)); |
|
} |
|
|
|
trans_alpha = 0; |
|
num = 2; /* force error below */ |
|
if ((png_get_tRNS(pp, pi, &trans_alpha, &num, 0) & PNG_INFO_tRNS) != 0 && |
|
(trans_alpha != NULL || num != 1/*returns 1 for a transparent color*/) && |
|
/* Oops, if a palette tRNS gets expanded png_read_update_info (at least so |
|
* far as 1.5.4) does not remove the trans_alpha pointer, only num_trans, |
|
* so in the above call we get a success, we get a pointer (who knows what |
|
* to) and we get num_trans == 0: |
|
*/ |
|
!(trans_alpha != NULL && num == 0)) /* TODO: fix this in libpng. */ |
|
{ |
|
int i; |
|
|
|
/* Any of these are crash-worthy - given the implementation of |
|
* png_get_tRNS up to 1.5 an app won't crash if it just checks the |
|
* result above and fails to check that the variables it passed have |
|
* actually been filled in! Note that if the app were to pass the |
|
* last, png_color_16p, variable too it couldn't rely on this. |
|
*/ |
|
if (trans_alpha == NULL || num <= 0 || num > 256 || num > *npalette) |
|
png_error(pp, "validate: unexpected png_get_tRNS (palette) result"); |
|
|
|
for (i=0; i<num; ++i) |
|
palette[i].alpha = trans_alpha[i]; |
|
|
|
for (num=*npalette; i<num; ++i) |
|
palette[i].alpha = 255; |
|
|
|
for (; i<256; ++i) |
|
palette[i].alpha = 33; /* flag value */ |
|
|
|
return 1; /* transparency */ |
|
} |
|
|
|
else |
|
{ |
|
/* No palette transparency - just set the alpha channel to opaque. */ |
|
int i; |
|
|
|
for (i=0, num=*npalette; i<num; ++i) |
|
palette[i].alpha = 255; |
|
|
|
for (; i<256; ++i) |
|
palette[i].alpha = 55; /* flag value */ |
|
|
|
return 0; /* no transparency */ |
|
} |
|
} |
|
|
|
/* Utility to validate the palette if it should not have changed (the |
|
* non-transform case). |
|
*/ |
|
static void |
|
standard_palette_validate(standard_display *dp, png_const_structp pp, |
|
png_infop pi) |
|
{ |
|
int npalette; |
|
store_palette palette; |
|
|
|
if (read_palette(palette, &npalette, pp, pi) != dp->is_transparent) |
|
png_error(pp, "validate: palette transparency changed"); |
|
|
|
if (npalette != dp->npalette) |
|
{ |
|
size_t pos = 0; |
|
char msg[64]; |
|
|
|
pos = safecat(msg, sizeof msg, pos, "validate: palette size changed: "); |
|
pos = safecatn(msg, sizeof msg, pos, dp->npalette); |
|
pos = safecat(msg, sizeof msg, pos, " -> "); |
|
pos = safecatn(msg, sizeof msg, pos, npalette); |
|
png_error(pp, msg); |
|
} |
|
|
|
{ |
|
int i = npalette; /* npalette is aliased */ |
|
|
|
while (--i >= 0) |
|
if (palette[i].red != dp->palette[i].red || |
|
palette[i].green != dp->palette[i].green || |
|
palette[i].blue != dp->palette[i].blue || |
|
palette[i].alpha != dp->palette[i].alpha) |
|
png_error(pp, "validate: PLTE or tRNS chunk changed"); |
|
} |
|
} |
|
|
|
/* By passing a 'standard_display' the progressive callbacks can be used |
|
* directly by the sequential code, the functions suffixed "_imp" are the |
|
* implementations, the functions without the suffix are the callbacks. |
|
* |
|
* The code for the info callback is split into two because this callback calls |
|
* png_read_update_info or png_start_read_image and what gets called depends on |
|
* whether the info needs updating (we want to test both calls in pngvalid.) |
|
*/ |
|
static void |
|
standard_info_part1(standard_display *dp, png_structp pp, png_infop pi) |
|
{ |
|
if (png_get_bit_depth(pp, pi) != dp->bit_depth) |
|
png_error(pp, "validate: bit depth changed"); |
|
|
|
if (png_get_color_type(pp, pi) != dp->colour_type) |
|
png_error(pp, "validate: color type changed"); |
|
|
|
if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE) |
|
png_error(pp, "validate: filter type changed"); |
|
|
|
if (png_get_interlace_type(pp, pi) != dp->interlace_type) |
|
png_error(pp, "validate: interlacing changed"); |
|
|
|
if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE) |
|
png_error(pp, "validate: compression type changed"); |
|
|
|
dp->w = png_get_image_width(pp, pi); |
|
|
|
if (dp->w != standard_width(pp, dp->id)) |
|
png_error(pp, "validate: image width changed"); |
|
|
|
dp->h = png_get_image_height(pp, pi); |
|
|
|
if (dp->h != standard_height(pp, dp->id)) |
|
png_error(pp, "validate: image height changed"); |
|
|
|
/* Record (but don't check at present) the input sBIT according to the colour |
|
* type information. |
|
*/ |
|
{ |
|
png_color_8p sBIT = 0; |
|
|
|
if (png_get_sBIT(pp, pi, &sBIT) & PNG_INFO_sBIT) |
|
{ |
|
int sBIT_invalid = 0; |
|
|
|
if (sBIT == 0) |
|
png_error(pp, "validate: unexpected png_get_sBIT result"); |
|
|
|
if (dp->colour_type & PNG_COLOR_MASK_COLOR) |
|
{ |
|
if (sBIT->red == 0 || sBIT->red > dp->bit_depth) |
|
sBIT_invalid = 1; |
|
else |
|
dp->red_sBIT = sBIT->red; |
|
|
|
if (sBIT->green == 0 || sBIT->green > dp->bit_depth) |
|
sBIT_invalid = 1; |
|
else |
|
dp->green_sBIT = sBIT->green; |
|
|
|
if (sBIT->blue == 0 || sBIT->blue > dp->bit_depth) |
|
sBIT_invalid = 1; |
|
else |
|
dp->blue_sBIT = sBIT->blue; |
|
} |
|
|
|
else /* !COLOR */ |
|
{ |
|
if (sBIT->gray == 0 || sBIT->gray > dp->bit_depth) |
|
sBIT_invalid = 1; |
|
else |
|
dp->blue_sBIT = dp->green_sBIT = dp->red_sBIT = sBIT->gray; |
|
} |
|
|
|
/* All 8 bits in tRNS for a palette image are significant - see the |
|
* spec. |
|
*/ |
|
if (dp->colour_type & PNG_COLOR_MASK_ALPHA) |
|
{ |
|
if (sBIT->alpha == 0 || sBIT->alpha > dp->bit_depth) |
|
sBIT_invalid = 1; |
|
else |
|
dp->alpha_sBIT = sBIT->alpha; |
|
} |
|
|
|
if (sBIT_invalid) |
|
png_error(pp, "validate: sBIT value out of range"); |
|
} |
|
} |
|
|
|
/* Important: this is validating the value *before* any transforms have been |
|
* put in place. It doesn't matter for the standard tests, where there are |
|
* no transforms, but it does for other tests where rowbytes may change after |
|
* png_read_update_info. |
|
*/ |
|
if (png_get_rowbytes(pp, pi) != standard_rowsize(pp, dp->id)) |
|
png_error(pp, "validate: row size changed"); |
|
|
|
/* Validate the colour type 3 palette (this can be present on other color |
|
* types.) |
|
*/ |
|
standard_palette_validate(dp, pp, pi); |
|
|
|
/* In any case always check for a transparent color (notice that the |
|
* colour type 3 case must not give a successful return on the get_tRNS call |
|
* with these arguments!) |
|
*/ |
|
{ |
|
png_color_16p trans_color = 0; |
|
|
|
if (png_get_tRNS(pp, pi, 0, 0, &trans_color) & PNG_INFO_tRNS) |
|
{ |
|
if (trans_color == 0) |
|
png_error(pp, "validate: unexpected png_get_tRNS (color) result"); |
|
|
|
switch (dp->colour_type) |
|
{ |
|
case 0: |
|
dp->transparent.red = dp->transparent.green = dp->transparent.blue = |
|
trans_color->gray; |
|
dp->has_tRNS = 1; |
|
break; |
|
|
|
case 2: |
|
dp->transparent.red = trans_color->red; |
|
dp->transparent.green = trans_color->green; |
|
dp->transparent.blue = trans_color->blue; |
|
dp->has_tRNS = 1; |
|
break; |
|
|
|
case 3: |
|
/* Not expected because it should result in the array case |
|
* above. |
|
*/ |
|
png_error(pp, "validate: unexpected png_get_tRNS result"); |
|
break; |
|
|
|
default: |
|
png_error(pp, "validate: invalid tRNS chunk with alpha image"); |
|
} |
|
} |
|
} |
|
|
|
/* Read the number of passes - expected to match the value used when |
|
* creating the image (interlaced or not). This has the side effect of |
|
* turning on interlace handling (if do_interlace is not set.) |
|
*/ |
|
dp->npasses = npasses_from_interlace_type(pp, dp->interlace_type); |
|
if (!dp->do_interlace) |
|
{ |
|
# ifdef PNG_READ_INTERLACING_SUPPORTED |
|
if (dp->npasses != png_set_interlace_handling(pp)) |
|
png_error(pp, "validate: file changed interlace type"); |
|
# else /* !READ_INTERLACING */ |
|
/* This should never happen: the relevant tests (!do_interlace) should |
|
* not be run. |
|
*/ |
|
if (dp->npasses > 1) |
|
png_error(pp, "validate: no libpng interlace support"); |
|
# endif /* !READ_INTERLACING */ |
|
} |
|
|
|
/* Caller calls png_read_update_info or png_start_read_image now, then calls |
|
* part2. |
|
*/ |
|
} |
|
|
|
/* This must be called *after* the png_read_update_info call to get the correct |
|
* 'rowbytes' value, otherwise png_get_rowbytes will refer to the untransformed |
|
* image. |
|
*/ |
|
static void |
|
standard_info_part2(standard_display *dp, png_const_structp pp, |
|
png_const_infop pi, int nImages) |
|
{ |
|
/* Record cbRow now that it can be found. */ |
|
{ |
|
png_byte ct = png_get_color_type(pp, pi); |
|
png_byte bd = png_get_bit_depth(pp, pi); |
|
|
|
if (bd >= 8 && (ct == PNG_COLOR_TYPE_RGB || ct == PNG_COLOR_TYPE_GRAY) && |
|
dp->filler) |
|
ct |= 4; /* handle filler as faked alpha channel */ |
|
|
|
dp->pixel_size = bit_size(pp, ct, bd); |
|
} |
|
dp->bit_width = png_get_image_width(pp, pi) * dp->pixel_size; |
|
dp->cbRow = png_get_rowbytes(pp, pi); |
|
|
|
/* Validate the rowbytes here again. */ |
|
if (dp->cbRow != (dp->bit_width+7)/8) |
|
png_error(pp, "bad png_get_rowbytes calculation"); |
|
|
|
/* Then ensure there is enough space for the output image(s). */ |
|
store_ensure_image(dp->ps, pp, nImages, dp->cbRow, dp->h); |
|
} |
|
|
|
static void |
|
standard_info_imp(standard_display *dp, png_structp pp, png_infop pi, |
|
int nImages) |
|
{ |
|
/* Note that the validation routine has the side effect of turning on |
|
* interlace handling in the subsequent code. |
|
*/ |
|
standard_info_part1(dp, pp, pi); |
|
|
|
/* And the info callback has to call this (or png_read_update_info - see |
|
* below in the png_modifier code for that variant. |
|
*/ |
|
if (dp->use_update_info) |
|
{ |
|
/* For debugging the effect of multiple calls: */ |
|
int i = dp->use_update_info; |
|
while (i-- > 0) |
|
png_read_update_info(pp, pi); |
|
} |
|
|
|
else |
|
png_start_read_image(pp); |
|
|
|
/* Validate the height, width and rowbytes plus ensure that sufficient buffer |
|
* exists for decoding the image. |
|
*/ |
|
standard_info_part2(dp, pp, pi, nImages); |
|
} |
|
|
|
static void PNGCBAPI |
|
standard_info(png_structp pp, png_infop pi) |
|
{ |
|
standard_display *dp = voidcast(standard_display*, |
|
png_get_progressive_ptr(pp)); |
|
|
|
/* Call with nImages==1 because the progressive reader can only produce one |
|
* image. |
|
*/ |
|
standard_info_imp(dp, pp, pi, 1 /*only one image*/); |
|
} |
|
|
|
static void PNGCBAPI |
|
progressive_row(png_structp ppIn, png_bytep new_row, png_uint_32 y, int pass) |
|
{ |
|
png_const_structp pp = ppIn; |
|
const standard_display *dp = voidcast(standard_display*, |
|
png_get_progressive_ptr(pp)); |
|
|
|
/* When handling interlacing some rows will be absent in each pass, the |
|
* callback still gets called, but with a NULL pointer. This is checked |
|
* in the 'else' clause below. We need our own 'cbRow', but we can't call |
|
* png_get_rowbytes because we got no info structure. |
|
*/ |
|
if (new_row != NULL) |
|
{ |
|
png_bytep row; |
|
|
|
/* In the case where the reader doesn't do the interlace it gives |
|
* us the y in the sub-image: |
|
*/ |
|
if (dp->do_interlace && dp->interlace_type == PNG_INTERLACE_ADAM7) |
|
{ |
|
#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED |
|
/* Use this opportunity to validate the png 'current' APIs: */ |
|
if (y != png_get_current_row_number(pp)) |
|
png_error(pp, "png_get_current_row_number is broken"); |
|
|
|
if (pass != png_get_current_pass_number(pp)) |
|
png_error(pp, "png_get_current_pass_number is broken"); |
|
#endif /* USER_TRANSFORM_INFO */ |
|
|
|
y = PNG_ROW_FROM_PASS_ROW(y, pass); |
|
} |
|
|
|
/* Validate this just in case. */ |
|
if (y >= dp->h) |
|
png_error(pp, "invalid y to progressive row callback"); |
|
|
|
row = store_image_row(dp->ps, pp, 0, y); |
|
|
|
/* Combine the new row into the old: */ |
|
#ifdef PNG_READ_INTERLACING_SUPPORTED |
|
if (dp->do_interlace) |
|
#endif /* READ_INTERLACING */ |
|
{ |
|
if (dp->interlace_type == PNG_INTERLACE_ADAM7) |
|
deinterlace_row(row, new_row, dp->pixel_size, dp->w, pass, |
|
dp->littleendian); |
|
else |
|
row_copy(row, new_row, dp->pixel_size * dp->w, dp->littleendian); |
|
} |
|
#ifdef PNG_READ_INTERLACING_SUPPORTED |
|
else |
|
png_progressive_combine_row(pp, row, new_row); |
|
#endif /* PNG_READ_INTERLACING_SUPPORTED */ |
|
} |
|
|
|
else if (dp->interlace_type == PNG_INTERLACE_ADAM7 && |
|
PNG_ROW_IN_INTERLACE_PASS(y, pass) && |
|
PNG_PASS_COLS(dp->w, pass) > 0) |
|
png_error(pp, "missing row in progressive de-interlacing"); |
|
} |
|
|
|
static void |
|
sequential_row(standard_display *dp, png_structp pp, png_infop pi, |
|
int iImage, int iDisplay) |
|
{ |
|
int npasses = dp->npasses; |
|
int do_interlace = dp->do_interlace && |
|
dp->interlace_type == PNG_INTERLACE_ADAM7; |
|
png_uint_32 height = standard_height(pp, dp->id); |
|
png_uint_32 width = standard_width(pp, dp->id); |
|
const png_store* ps = dp->ps; |
|
int pass; |
|
|
|
for (pass=0; pass<npasses; ++pass) |
|
{ |
|
png_uint_32 y; |
|
png_uint_32 wPass = PNG_PASS_COLS(width, pass); |
|
|
|
for (y=0; y<height; ++y) |
|
{ |
|
if (do_interlace) |
|
{ |
|
/* wPass may be zero or this row may not be in this pass. |
|
* png_read_row must not be called in either case. |
|
*/ |
|
if (wPass > 0 && PNG_ROW_IN_INTERLACE_PASS(y, pass)) |
|
{ |
|
/* Read the row into a pair of temporary buffers, then do the |
|
* merge here into the output rows. |
|
*/ |
|
png_byte row[STANDARD_ROWMAX], display[STANDARD_ROWMAX]; |
|
|
|
/* The following aids (to some extent) error detection - we can |
|
* see where png_read_row wrote. Use opposite values in row and |
|
* display to make this easier. Don't use 0xff (which is used in |
|
* the image write code to fill unused bits) or 0 (which is a |
|
* likely value to overwrite unused bits with). |
|
*/ |
|
memset(row, 0xc5, sizeof row); |
|
memset(display, 0x5c, sizeof display); |
|
|
|
png_read_row(pp, row, display); |
|
|
|
if (iImage >= 0) |
|
deinterlace_row(store_image_row(ps, pp, iImage, y), row, |
|
dp->pixel_size, dp->w, pass, dp->littleendian); |
|
|
|
if (iDisplay >= 0) |
|
deinterlace_row(store_image_row(ps, pp, iDisplay, y), display, |
|
dp->pixel_size, dp->w, pass, dp->littleendian); |
|
} |
|
} |
|
else |
|
png_read_row(pp, |
|
iImage >= 0 ? store_image_row(ps, pp, iImage, y) : NULL, |
|
iDisplay >= 0 ? store_image_row(ps, pp, iDisplay, y) : NULL); |
|
} |
|
} |
|
|
|
/* And finish the read operation (only really necessary if the caller wants |
|
* to find additional data in png_info from chunks after the last IDAT.) |
|
*/ |
|
png_read_end(pp, pi); |
|
} |
|
|
|
#ifdef PNG_TEXT_SUPPORTED |
|
static void |
|
standard_check_text(png_const_structp pp, png_const_textp tp, |
|
png_const_charp keyword, png_const_charp text) |
|
{ |
|
char msg[1024]; |
|
size_t pos = safecat(msg, sizeof msg, 0, "text: "); |
|
size_t ok; |
|
|
|
pos = safecat(msg, sizeof msg, pos, keyword); |
|
pos = safecat(msg, sizeof msg, pos, ": "); |
|
ok = pos; |
|
|
|
if (tp->compression != TEXT_COMPRESSION) |
|
{ |
|
char buf[64]; |
|
|
|
sprintf(buf, "compression [%d->%d], ", TEXT_COMPRESSION, |
|
tp->compression); |
|
pos = safecat(msg, sizeof msg, pos, buf); |
|
} |
|
|
|
if (tp->key == NULL || strcmp(tp->key, keyword) != 0) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, "keyword \""); |
|
if (tp->key != NULL) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, tp->key); |
|
pos = safecat(msg, sizeof msg, pos, "\", "); |
|
} |
|
|
|
else |
|
pos = safecat(msg, sizeof msg, pos, "null, "); |
|
} |
|
|
|
if (tp->text == NULL) |
|
pos = safecat(msg, sizeof msg, pos, "text lost, "); |
|
|
|
else |
|
{ |
|
if (tp->text_length != strlen(text)) |
|
{ |
|
char buf[64]; |
|
sprintf(buf, "text length changed[%lu->%lu], ", |
|
(unsigned long)strlen(text), (unsigned long)tp->text_length); |
|
pos = safecat(msg, sizeof msg, pos, buf); |
|
} |
|
|
|
if (strcmp(tp->text, text) != 0) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, "text becomes \""); |
|
pos = safecat(msg, sizeof msg, pos, tp->text); |
|
pos = safecat(msg, sizeof msg, pos, "\" (was \""); |
|
pos = safecat(msg, sizeof msg, pos, text); |
|
pos = safecat(msg, sizeof msg, pos, "\"), "); |
|
} |
|
} |
|
|
|
if (tp->itxt_length != 0) |
|
pos = safecat(msg, sizeof msg, pos, "iTXt length set, "); |
|
|
|
if (tp->lang != NULL) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, "iTXt language \""); |
|
pos = safecat(msg, sizeof msg, pos, tp->lang); |
|
pos = safecat(msg, sizeof msg, pos, "\", "); |
|
} |
|
|
|
if (tp->lang_key != NULL) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, "iTXt keyword \""); |
|
pos = safecat(msg, sizeof msg, pos, tp->lang_key); |
|
pos = safecat(msg, sizeof msg, pos, "\", "); |
|
} |
|
|
|
if (pos > ok) |
|
{ |
|
msg[pos-2] = '\0'; /* Remove the ", " at the end */ |
|
png_error(pp, msg); |
|
} |
|
} |
|
|
|
static void |
|
standard_text_validate(standard_display *dp, png_const_structp pp, |
|
png_infop pi, int check_end) |
|
{ |
|
png_textp tp = NULL; |
|
png_uint_32 num_text = png_get_text(pp, pi, &tp, NULL); |
|
|
|
if (num_text == 2 && tp != NULL) |
|
{ |
|
standard_check_text(pp, tp, "image name", dp->ps->current->name); |
|
|
|
/* This exists because prior to 1.5.18 the progressive reader left the |
|
* png_struct z_stream unreset at the end of the image, so subsequent |
|
* attempts to use it simply returns Z_STREAM_END. |
|
*/ |
|
if (check_end) |
|
standard_check_text(pp, tp+1, "end marker", "end"); |
|
} |
|
|
|
else |
|
{ |
|
char msg[64]; |
|
|
|
sprintf(msg, "expected two text items, got %lu", |
|
(unsigned long)num_text); |
|
png_error(pp, msg); |
|
} |
|
} |
|
#else |
|
# define standard_text_validate(dp,pp,pi,check_end) ((void)0) |
|
#endif |
|
|
|
static void |
|
standard_row_validate(standard_display *dp, png_const_structp pp, |
|
int iImage, int iDisplay, png_uint_32 y) |
|
{ |
|
int where; |
|
png_byte std[STANDARD_ROWMAX]; |
|
|
|
/* The row must be pre-initialized to the magic number here for the size |
|
* tests to pass: |
|
*/ |
|
memset(std, 178, sizeof std); |
|
standard_row(pp, std, dp->id, y); |
|
|
|
/* At the end both the 'row' and 'display' arrays should end up identical. |
|
* In earlier passes 'row' will be partially filled in, with only the pixels |
|
* that have been read so far, but 'display' will have those pixels |
|
* replicated to fill the unread pixels while reading an interlaced image. |
|
*/ |
|
if (iImage >= 0 && |
|
(where = pixel_cmp(std, store_image_row(dp->ps, pp, iImage, y), |
|
dp->bit_width)) != 0) |
|
{ |
|
char msg[64]; |
|
sprintf(msg, "PNG image row[%lu][%d] changed from %.2x to %.2x", |
|
(unsigned long)y, where-1, std[where-1], |
|
store_image_row(dp->ps, pp, iImage, y)[where-1]); |
|
png_error(pp, msg); |
|
} |
|
|
|
if (iDisplay >= 0 && |
|
(where = pixel_cmp(std, store_image_row(dp->ps, pp, iDisplay, y), |
|
dp->bit_width)) != 0) |
|
{ |
|
char msg[64]; |
|
sprintf(msg, "display row[%lu][%d] changed from %.2x to %.2x", |
|
(unsigned long)y, where-1, std[where-1], |
|
store_image_row(dp->ps, pp, iDisplay, y)[where-1]); |
|
png_error(pp, msg); |
|
} |
|
} |
|
|
|
static void |
|
standard_image_validate(standard_display *dp, png_const_structp pp, int iImage, |
|
int iDisplay) |
|
{ |
|
png_uint_32 y; |
|
|
|
if (iImage >= 0) |
|
store_image_check(dp->ps, pp, iImage); |
|
|
|
if (iDisplay >= 0) |
|
store_image_check(dp->ps, pp, iDisplay); |
|
|
|
for (y=0; y<dp->h; ++y) |
|
standard_row_validate(dp, pp, iImage, iDisplay, y); |
|
|
|
/* This avoids false positives if the validation code is never called! */ |
|
dp->ps->validated = 1; |
|
} |
|
|
|
static void PNGCBAPI |
|
standard_end(png_structp ppIn, png_infop pi) |
|
{ |
|
png_const_structp pp = ppIn; |
|
standard_display *dp = voidcast(standard_display*, |
|
png_get_progressive_ptr(pp)); |
|
|
|
UNUSED(pi) |
|
|
|
/* Validate the image - progressive reading only produces one variant for |
|
* interlaced images. |
|
*/ |
|
standard_text_validate(dp, pp, pi, |
|
PNG_LIBPNG_VER >= 10518/*check_end: see comments above*/); |
|
standard_image_validate(dp, pp, 0, -1); |
|
} |
|
|
|
/* A single test run checking the standard image to ensure it is not damaged. */ |
|
static void |
|
standard_test(png_store* const psIn, png_uint_32 const id, |
|
int do_interlace, int use_update_info) |
|
{ |
|
standard_display d; |
|
context(psIn, fault); |
|
|
|
/* Set up the display (stack frame) variables from the arguments to the |
|
* function and initialize the locals that are filled in later. |
|
*/ |
|
standard_display_init(&d, psIn, id, do_interlace, use_update_info); |
|
|
|
/* Everything is protected by a Try/Catch. The functions called also |
|
* typically have local Try/Catch blocks. |
|
*/ |
|
Try |
|
{ |
|
png_structp pp; |
|
png_infop pi; |
|
|
|
/* Get a png_struct for reading the image. This will throw an error if it |
|
* fails, so we don't need to check the result. |
|
*/ |
|
pp = set_store_for_read(d.ps, &pi, d.id, |
|
d.do_interlace ? (d.ps->progressive ? |
|
"pngvalid progressive deinterlacer" : |
|
"pngvalid sequential deinterlacer") : (d.ps->progressive ? |
|
"progressive reader" : "sequential reader")); |
|
|
|
/* Initialize the palette correctly from the png_store_file. */ |
|
standard_palette_init(&d); |
|
|
|
/* Introduce the correct read function. */ |
|
if (d.ps->progressive) |
|
{ |
|
png_set_progressive_read_fn(pp, &d, standard_info, progressive_row, |
|
standard_end); |
|
|
|
/* Now feed data into the reader until we reach the end: */ |
|
store_progressive_read(d.ps, pp, pi); |
|
} |
|
else |
|
{ |
|
/* Note that this takes the store, not the display. */ |
|
png_set_read_fn(pp, d.ps, store_read); |
|
|
|
/* Check the header values: */ |
|
png_read_info(pp, pi); |
|
|
|
/* The code tests both versions of the images that the sequential |
|
* reader can produce. |
|
*/ |
|
standard_info_imp(&d, pp, pi, 2 /*images*/); |
|
|
|
/* Need the total bytes in the image below; we can't get to this point |
|
* unless the PNG file values have been checked against the expected |
|
* values. |
|
*/ |
|
{ |
|
sequential_row(&d, pp, pi, 0, 1); |
|
|
|
/* After the last pass loop over the rows again to check that the |
|
* image is correct. |
|
*/ |
|
if (!d.speed) |
|
{ |
|
standard_text_validate(&d, pp, pi, 1/*check_end*/); |
|
standard_image_validate(&d, pp, 0, 1); |
|
} |
|
else |
|
d.ps->validated = 1; |
|
} |
|
} |
|
|
|
/* Check for validation. */ |
|
if (!d.ps->validated) |
|
png_error(pp, "image read failed silently"); |
|
|
|
/* Successful completion. */ |
|
} |
|
|
|
Catch(fault) |
|
d.ps = fault; /* make sure this hasn't been clobbered. */ |
|
|
|
/* In either case clean up the store. */ |
|
store_read_reset(d.ps); |
|
} |
|
|
|
static int |
|
test_standard(png_modifier* const pm, png_byte const colour_type, |
|
int bdlo, int const bdhi) |
|
{ |
|
for (; bdlo <= bdhi; ++bdlo) |
|
{ |
|
int interlace_type; |
|
|
|
for (interlace_type = PNG_INTERLACE_NONE; |
|
interlace_type < INTERLACE_LAST; ++interlace_type) |
|
{ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
interlace_type, 0, 0, 0), do_read_interlace, pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
} |
|
} |
|
|
|
return 1; /* keep going */ |
|
} |
|
|
|
static void |
|
perform_standard_test(png_modifier *pm) |
|
{ |
|
/* Test each colour type over the valid range of bit depths (expressed as |
|
* log2(bit_depth) in turn, stop as soon as any error is detected. |
|
*/ |
|
if (!test_standard(pm, 0, 0, READ_BDHI)) |
|
return; |
|
|
|
if (!test_standard(pm, 2, 3, READ_BDHI)) |
|
return; |
|
|
|
if (!test_standard(pm, 3, 0, 3)) |
|
return; |
|
|
|
if (!test_standard(pm, 4, 3, READ_BDHI)) |
|
return; |
|
|
|
if (!test_standard(pm, 6, 3, READ_BDHI)) |
|
return; |
|
} |
|
|
|
|
|
/********************************** SIZE TESTS ********************************/ |
|
static int |
|
test_size(png_modifier* const pm, png_byte const colour_type, |
|
int bdlo, int const bdhi) |
|
{ |
|
/* Run the tests on each combination. |
|
* |
|
* NOTE: on my 32 bit x86 each of the following blocks takes |
|
* a total of 3.5 seconds if done across every combo of bit depth |
|
* width and height. This is a waste of time in practice, hence the |
|
* hinc and winc stuff: |
|
*/ |
|
static const png_byte hinc[] = {1, 3, 11, 1, 5}; |
|
static const png_byte winc[] = {1, 9, 5, 7, 1}; |
|
int save_bdlo = bdlo; |
|
|
|
for (; bdlo <= bdhi; ++bdlo) |
|
{ |
|
png_uint_32 h, w; |
|
|
|
for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) |
|
{ |
|
/* First test all the 'size' images against the sequential |
|
* reader using libpng to deinterlace (where required.) This |
|
* validates the write side of libpng. There are four possibilities |
|
* to validate. |
|
*/ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_NONE, w, h, 0), 0/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
|
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_NONE, w, h, 1), 0/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
|
|
/* Now validate the interlaced read side - do_interlace true, |
|
* in the progressive case this does actually make a difference |
|
* to the code used in the non-interlaced case too. |
|
*/ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_NONE, w, h, 0), 1/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
|
|
# if CAN_WRITE_INTERLACE |
|
/* Validate the pngvalid code itself: */ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_ADAM7, w, h, 1), 1/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
# endif |
|
} |
|
} |
|
|
|
/* Now do the tests of libpng interlace handling, after we have made sure |
|
* that the pngvalid version works: |
|
*/ |
|
for (bdlo = save_bdlo; bdlo <= bdhi; ++bdlo) |
|
{ |
|
png_uint_32 h, w; |
|
|
|
for (h=1; h<=16; h+=hinc[bdlo]) for (w=1; w<=16; w+=winc[bdlo]) |
|
{ |
|
# ifdef PNG_READ_INTERLACING_SUPPORTED |
|
/* Test with pngvalid generated interlaced images first; we have |
|
* already verify these are ok (unless pngvalid has self-consistent |
|
* read/write errors, which is unlikely), so this detects errors in the |
|
* read side first: |
|
*/ |
|
# if CAN_WRITE_INTERLACE |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_ADAM7, w, h, 1), 0/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
# endif |
|
# endif /* READ_INTERLACING */ |
|
|
|
# ifdef PNG_WRITE_INTERLACING_SUPPORTED |
|
/* Test the libpng write side against the pngvalid read side: */ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_ADAM7, w, h, 0), 1/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
# endif |
|
|
|
# ifdef PNG_READ_INTERLACING_SUPPORTED |
|
# ifdef PNG_WRITE_INTERLACING_SUPPORTED |
|
/* Test both together: */ |
|
standard_test(&pm->this, FILEID(colour_type, DEPTH(bdlo), 0/*palette*/, |
|
PNG_INTERLACE_ADAM7, w, h, 0), 0/*do_interlace*/, |
|
pm->use_update_info); |
|
|
|
if (fail(pm)) |
|
return 0; |
|
# endif |
|
# endif /* READ_INTERLACING */ |
|
} |
|
} |
|
|
|
return 1; /* keep going */ |
|
} |
|
|
|
static void |
|
perform_size_test(png_modifier *pm) |
|
{ |
|
/* Test each colour type over the valid range of bit depths (expressed as |
|
* log2(bit_depth) in turn, stop as soon as any error is detected. |
|
*/ |
|
if (!test_size(pm, 0, 0, READ_BDHI)) |
|
return; |
|
|
|
if (!test_size(pm, 2, 3, READ_BDHI)) |
|
return; |
|
|
|
/* For the moment don't do the palette test - it's a waste of time when |
|
* compared to the grayscale test. |
|
*/ |
|
#if 0 |
|
if (!test_size(pm, 3, 0, 3)) |
|
return; |
|
#endif |
|
|
|
if (!test_size(pm, 4, 3, READ_BDHI)) |
|
return; |
|
|
|
if (!test_size(pm, 6, 3, READ_BDHI)) |
|
return; |
|
} |
|
|
|
|
|
/******************************* TRANSFORM TESTS ******************************/ |
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
/* A set of tests to validate libpng image transforms. The possibilities here |
|
* are legion because the transforms can be combined in a combinatorial |
|
* fashion. To deal with this some measure of restraint is required, otherwise |
|
* the tests would take forever. |
|
*/ |
|
typedef struct image_pixel |
|
{ |
|
/* A local (pngvalid) representation of a PNG pixel, in all its |
|
* various forms. |
|
*/ |
|
unsigned int red, green, blue, alpha; /* For non-palette images. */ |
|
unsigned int palette_index; /* For a palette image. */ |
|
png_byte colour_type; /* As in the spec. */ |
|
png_byte bit_depth; /* Defines bit size in row */ |
|
png_byte sample_depth; /* Scale of samples */ |
|
unsigned int have_tRNS :1; /* tRNS chunk may need processing */ |
|
unsigned int swap_rgb :1; /* RGB swapped to BGR */ |
|
unsigned int alpha_first :1; /* Alpha at start, not end */ |
|
unsigned int alpha_inverted :1; /* Alpha channel inverted */ |
|
unsigned int mono_inverted :1; /* Gray channel inverted */ |
|
unsigned int swap16 :1; /* Byte swap 16-bit components */ |
|
unsigned int littleendian :1; /* High bits on right */ |
|
unsigned int sig_bits :1; /* Pixel shifted (sig bits only) */ |
|
|
|
/* For checking the code calculates double precision floating point values |
|
* along with an error value, accumulated from the transforms. Because an |
|
* sBIT setting allows larger error bounds (indeed, by the spec, apparently |
|
* up to just less than +/-1 in the scaled value) the *lowest* sBIT for each |
|
* channel is stored. This sBIT value is folded in to the stored error value |
|
* at the end of the application of the transforms to the pixel. |
|
* |
|
* If sig_bits is set above the red, green, blue and alpha values have been |
|
* scaled so they only contain the significant bits of the component values. |
|
*/ |
|
double redf, greenf, bluef, alphaf; |
|
double rede, greene, bluee, alphae; |
|
png_byte red_sBIT, green_sBIT, blue_sBIT, alpha_sBIT; |
|
} image_pixel; |
|
|
|
/* Shared utility function, see below. */ |
|
static void |
|
image_pixel_setf(image_pixel *this, unsigned int rMax, unsigned int gMax, |
|
unsigned int bMax, unsigned int aMax) |
|
{ |
|
this->redf = this->red / (double)rMax; |
|
this->greenf = this->green / (double)gMax; |
|
this->bluef = this->blue / (double)bMax; |
|
this->alphaf = this->alpha / (double)aMax; |
|
|
|
if (this->red < rMax) |
|
this->rede = this->redf * DBL_EPSILON; |
|
else |
|
this->rede = 0; |
|
if (this->green < gMax) |
|
this->greene = this->greenf * DBL_EPSILON; |
|
else |
|
this->greene = 0; |
|
if (this->blue < bMax) |
|
this->bluee = this->bluef * DBL_EPSILON; |
|
else |
|
this->bluee = 0; |
|
if (this->alpha < aMax) |
|
this->alphae = this->alphaf * DBL_EPSILON; |
|
else |
|
this->alphae = 0; |
|
} |
|
|
|
/* Initialize the structure for the next pixel - call this before doing any |
|
* transforms and call it for each pixel since all the fields may need to be |
|
* reset. |
|
*/ |
|
static void |
|
image_pixel_init(image_pixel *this, png_const_bytep row, png_byte colour_type, |
|
png_byte bit_depth, png_uint_32 x, store_palette palette, |
|
const image_pixel *format /*from pngvalid transform of input*/) |
|
{ |
|
png_byte sample_depth = |
|
(png_byte)(colour_type == PNG_COLOR_TYPE_PALETTE ? 8 : bit_depth); |
|
unsigned int max = (1U<<sample_depth)-1; |
|
int swap16 = (format != 0 && format->swap16); |
|
int littleendian = (format != 0 && format->littleendian); |
|
int sig_bits = (format != 0 && format->sig_bits); |
|
|
|
/* Initially just set everything to the same number and the alpha to opaque. |
|
* Note that this currently assumes a simple palette where entry x has colour |
|
* rgb(x,x,x)! |
|
*/ |
|
this->palette_index = this->red = this->green = this->blue = |
|
sample(row, colour_type, bit_depth, x, 0, swap16, littleendian); |
|
this->alpha = max; |
|
this->red_sBIT = this->green_sBIT = this->blue_sBIT = this->alpha_sBIT = |
|
sample_depth; |
|
|
|
/* Then override as appropriate: */ |
|
if (colour_type == 3) /* palette */ |
|
{ |
|
/* This permits the caller to default to the sample value. */ |
|
if (palette != 0) |
|
{ |
|
unsigned int i = this->palette_index; |
|
|
|
this->red = palette[i].red; |
|
this->green = palette[i].green; |
|
this->blue = palette[i].blue; |
|
this->alpha = palette[i].alpha; |
|
} |
|
} |
|
|
|
else /* not palette */ |
|
{ |
|
unsigned int i = 0; |
|
|
|
if ((colour_type & 4) != 0 && format != 0 && format->alpha_first) |
|
{ |
|
this->alpha = this->red; |
|
/* This handles the gray case for 'AG' pixels */ |
|
this->palette_index = this->red = this->green = this->blue = |
|
sample(row, colour_type, bit_depth, x, 1, swap16, littleendian); |
|
i = 1; |
|
} |
|
|
|
if (colour_type & 2) |
|
{ |
|
/* Green is second for both BGR and RGB: */ |
|
this->green = sample(row, colour_type, bit_depth, x, ++i, swap16, |
|
littleendian); |
|
|
|
if (format != 0 && format->swap_rgb) /* BGR */ |
|
this->red = sample(row, colour_type, bit_depth, x, ++i, swap16, |
|
littleendian); |
|
else |
|
this->blue = sample(row, colour_type, bit_depth, x, ++i, swap16, |
|
littleendian); |
|
} |
|
|
|
else /* grayscale */ if (format != 0 && format->mono_inverted) |
|
this->red = this->green = this->blue = this->red ^ max; |
|
|
|
if ((colour_type & 4) != 0) /* alpha */ |
|
{ |
|
if (format == 0 || !format->alpha_first) |
|
this->alpha = sample(row, colour_type, bit_depth, x, ++i, swap16, |
|
littleendian); |
|
|
|
if (format != 0 && format->alpha_inverted) |
|
this->alpha ^= max; |
|
} |
|
} |
|
|
|
/* Calculate the scaled values, these are simply the values divided by |
|
* 'max' and the error is initialized to the double precision epsilon value |
|
* from the header file. |
|
*/ |
|
image_pixel_setf(this, |
|
sig_bits ? (1U << format->red_sBIT)-1 : max, |
|
sig_bits ? (1U << format->green_sBIT)-1 : max, |
|
sig_bits ? (1U << format->blue_sBIT)-1 : max, |
|
sig_bits ? (1U << format->alpha_sBIT)-1 : max); |
|
|
|
/* Store the input information for use in the transforms - these will |
|
* modify the information. |
|
*/ |
|
this->colour_type = colour_type; |
|
this->bit_depth = bit_depth; |
|
this->sample_depth = sample_depth; |
|
this->have_tRNS = 0; |
|
this->swap_rgb = 0; |
|
this->alpha_first = 0; |
|
this->alpha_inverted = 0; |
|
this->mono_inverted = 0; |
|
this->swap16 = 0; |
|
this->littleendian = 0; |
|
this->sig_bits = 0; |
|
} |
|
|
|
#if defined PNG_READ_EXPAND_SUPPORTED || defined PNG_READ_GRAY_TO_RGB_SUPPORTED\ |
|
|| defined PNG_READ_EXPAND_SUPPORTED || defined PNG_READ_EXPAND_16_SUPPORTED\ |
|
|| defined PNG_READ_BACKGROUND_SUPPORTED |
|
/* Convert a palette image to an rgb image. This necessarily converts the tRNS |
|
* chunk at the same time, because the tRNS will be in palette form. The way |
|
* palette validation works means that the original palette is never updated, |
|
* instead the image_pixel value from the row contains the RGB of the |
|
* corresponding palette entry and *this* is updated. Consequently this routine |
|
* only needs to change the colour type information. |
|
*/ |
|
static void |
|
image_pixel_convert_PLTE(image_pixel *this) |
|
{ |
|
if (this->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (this->have_tRNS) |
|
{ |
|
this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
this->have_tRNS = 0; |
|
} |
|
else |
|
this->colour_type = PNG_COLOR_TYPE_RGB; |
|
|
|
/* The bit depth of the row changes at this point too (notice that this is |
|
* the row format, not the sample depth, which is separate.) |
|
*/ |
|
this->bit_depth = 8; |
|
} |
|
} |
|
|
|
/* Add an alpha channel; this will import the tRNS information because tRNS is |
|
* not valid in an alpha image. The bit depth will invariably be set to at |
|
* least 8 prior to 1.7.0. Palette images will be converted to alpha (using |
|
* the above API). With png_set_background the alpha channel is never expanded |
|
* but this routine is used by pngvalid to simplify code; 'for_background' |
|
* records this. |
|
*/ |
|
static void |
|
image_pixel_add_alpha(image_pixel *this, const standard_display *display, |
|
int for_background) |
|
{ |
|
if (this->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(this); |
|
|
|
if ((this->colour_type & PNG_COLOR_MASK_ALPHA) == 0) |
|
{ |
|
if (this->colour_type == PNG_COLOR_TYPE_GRAY) |
|
{ |
|
# if PNG_LIBPNG_VER < 10700 |
|
if (!for_background && this->bit_depth < 8) |
|
this->bit_depth = this->sample_depth = 8; |
|
# endif |
|
|
|
if (this->have_tRNS) |
|
{ |
|
/* After 1.7 the expansion of bit depth only happens if there is a |
|
* tRNS chunk to expand at this point. |
|
*/ |
|
# if PNG_LIBPNG_VER >= 10700 |
|
if (!for_background && this->bit_depth < 8) |
|
this->bit_depth = this->sample_depth = 8; |
|
# endif |
|
|
|
this->have_tRNS = 0; |
|
|
|
/* Check the input, original, channel value here against the |
|
* original tRNS gray chunk valie. |
|
*/ |
|
if (this->red == display->transparent.red) |
|
this->alphaf = 0; |
|
else |
|
this->alphaf = 1; |
|
} |
|
else |
|
this->alphaf = 1; |
|
|
|
this->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
|
} |
|
|
|
else if (this->colour_type == PNG_COLOR_TYPE_RGB) |
|
{ |
|
if (this->have_tRNS) |
|
{ |
|
this->have_tRNS = 0; |
|
|
|
/* Again, check the exact input values, not the current transformed |
|
* value! |
|
*/ |
|
if (this->red == display->transparent.red && |
|
this->green == display->transparent.green && |
|
this->blue == display->transparent.blue) |
|
this->alphaf = 0; |
|
else |
|
this->alphaf = 1; |
|
} |
|
else |
|
this->alphaf = 1; |
|
|
|
this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
} |
|
|
|
/* The error in the alpha is zero and the sBIT value comes from the |
|
* original sBIT data (actually it will always be the original bit depth). |
|
*/ |
|
this->alphae = 0; |
|
this->alpha_sBIT = display->alpha_sBIT; |
|
} |
|
} |
|
#endif /* transforms that need image_pixel_add_alpha */ |
|
|
|
struct transform_display; |
|
typedef struct image_transform |
|
{ |
|
/* The name of this transform: a string. */ |
|
const char *name; |
|
|
|
/* Each transform can be disabled from the command line: */ |
|
int enable; |
|
|
|
/* The global list of transforms; read only. */ |
|
struct image_transform *const list; |
|
|
|
/* The global count of the number of times this transform has been set on an |
|
* image. |
|
*/ |
|
unsigned int global_use; |
|
|
|
/* The local count of the number of times this transform has been set. */ |
|
unsigned int local_use; |
|
|
|
/* The next transform in the list, each transform must call its own next |
|
* transform after it has processed the pixel successfully. |
|
*/ |
|
const struct image_transform *next; |
|
|
|
/* A single transform for the image, expressed as a series of function |
|
* callbacks and some space for values. |
|
* |
|
* First a callback to add any required modifications to the png_modifier; |
|
* this gets called just before the modifier is set up for read. |
|
*/ |
|
void (*ini)(const struct image_transform *this, |
|
struct transform_display *that); |
|
|
|
/* And a callback to set the transform on the current png_read_struct: |
|
*/ |
|
void (*set)(const struct image_transform *this, |
|
struct transform_display *that, png_structp pp, png_infop pi); |
|
|
|
/* Then a transform that takes an input pixel in one PNG format or another |
|
* and modifies it by a pngvalid implementation of the transform (thus |
|
* duplicating the libpng intent without, we hope, duplicating the bugs |
|
* in the libpng implementation!) The png_structp is solely to allow error |
|
* reporting via png_error and png_warning. |
|
*/ |
|
void (*mod)(const struct image_transform *this, image_pixel *that, |
|
png_const_structp pp, const struct transform_display *display); |
|
|
|
/* Add this transform to the list and return true if the transform is |
|
* meaningful for this colour type and bit depth - if false then the |
|
* transform should have no effect on the image so there's not a lot of |
|
* point running it. |
|
*/ |
|
int (*add)(struct image_transform *this, |
|
const struct image_transform **that, png_byte colour_type, |
|
png_byte bit_depth); |
|
} image_transform; |
|
|
|
typedef struct transform_display |
|
{ |
|
standard_display this; |
|
|
|
/* Parameters */ |
|
png_modifier* pm; |
|
const image_transform* transform_list; |
|
unsigned int max_gamma_8; |
|
|
|
/* Local variables */ |
|
png_byte output_colour_type; |
|
png_byte output_bit_depth; |
|
png_byte unpacked; |
|
|
|
/* Modifications (not necessarily used.) */ |
|
gama_modification gama_mod; |
|
chrm_modification chrm_mod; |
|
srgb_modification srgb_mod; |
|
} transform_display; |
|
|
|
/* Set sRGB, cHRM and gAMA transforms as required by the current encoding. */ |
|
static void |
|
transform_set_encoding(transform_display *this) |
|
{ |
|
/* Set up the png_modifier '_current' fields then use these to determine how |
|
* to add appropriate chunks. |
|
*/ |
|
png_modifier *pm = this->pm; |
|
|
|
modifier_set_encoding(pm); |
|
|
|
if (modifier_color_encoding_is_set(pm)) |
|
{ |
|
if (modifier_color_encoding_is_sRGB(pm)) |
|
srgb_modification_init(&this->srgb_mod, pm, PNG_sRGB_INTENT_ABSOLUTE); |
|
|
|
else |
|
{ |
|
/* Set gAMA and cHRM separately. */ |
|
gama_modification_init(&this->gama_mod, pm, pm->current_gamma); |
|
|
|
if (pm->current_encoding != 0) |
|
chrm_modification_init(&this->chrm_mod, pm, pm->current_encoding); |
|
} |
|
} |
|
} |
|
|
|
/* Three functions to end the list: */ |
|
static void |
|
image_transform_ini_end(const image_transform *this, |
|
transform_display *that) |
|
{ |
|
UNUSED(this) |
|
UNUSED(that) |
|
} |
|
|
|
static void |
|
image_transform_set_end(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
UNUSED(this) |
|
UNUSED(that) |
|
UNUSED(pp) |
|
UNUSED(pi) |
|
} |
|
|
|
/* At the end of the list recalculate the output image pixel value from the |
|
* double precision values set up by the preceding 'mod' calls: |
|
*/ |
|
static unsigned int |
|
sample_scale(double sample_value, unsigned int scale) |
|
{ |
|
sample_value = floor(sample_value * scale + .5); |
|
|
|
/* Return NaN as 0: */ |
|
if (!(sample_value > 0)) |
|
sample_value = 0; |
|
else if (sample_value > scale) |
|
sample_value = scale; |
|
|
|
return (unsigned int)sample_value; |
|
} |
|
|
|
static void |
|
image_transform_mod_end(const image_transform *this, image_pixel *that, |
|
png_const_structp pp, const transform_display *display) |
|
{ |
|
unsigned int scale = (1U<<that->sample_depth)-1; |
|
int sig_bits = that->sig_bits; |
|
|
|
UNUSED(this) |
|
UNUSED(pp) |
|
UNUSED(display) |
|
|
|
/* At the end recalculate the digitized red green and blue values according |
|
* to the current sample_depth of the pixel. |
|
* |
|
* The sample value is simply scaled to the maximum, checking for over |
|
* and underflow (which can both happen for some image transforms, |
|
* including simple size scaling, though libpng doesn't do that at present. |
|
*/ |
|
that->red = sample_scale(that->redf, scale); |
|
|
|
/* This is a bit bogus; really the above calculation should use the red_sBIT |
|
* value, not sample_depth, but because libpng does png_set_shift by just |
|
* shifting the bits we get errors if we don't do it the same way. |
|
*/ |
|
if (sig_bits && that->red_sBIT < that->sample_depth) |
|
that->red >>= that->sample_depth - that->red_sBIT; |
|
|
|
/* The error value is increased, at the end, according to the lowest sBIT |
|
* value seen. Common sense tells us that the intermediate integer |
|
* representations are no more accurate than +/- 0.5 in the integral values, |
|
* the sBIT allows the implementation to be worse than this. In addition the |
|
* PNG specification actually permits any error within the range (-1..+1), |
|
* but that is ignored here. Instead the final digitized value is compared, |
|
* below to the digitized value of the error limits - this has the net effect |
|
* of allowing (almost) +/-1 in the output value. It's difficult to see how |
|
* any algorithm that digitizes intermediate results can be more accurate. |
|
*/ |
|
that->rede += 1./(2*((1U<<that->red_sBIT)-1)); |
|
|
|
if (that->colour_type & PNG_COLOR_MASK_COLOR) |
|
{ |
|
that->green = sample_scale(that->greenf, scale); |
|
if (sig_bits && that->green_sBIT < that->sample_depth) |
|
that->green >>= that->sample_depth - that->green_sBIT; |
|
|
|
that->blue = sample_scale(that->bluef, scale); |
|
if (sig_bits && that->blue_sBIT < that->sample_depth) |
|
that->blue >>= that->sample_depth - that->blue_sBIT; |
|
|
|
that->greene += 1./(2*((1U<<that->green_sBIT)-1)); |
|
that->bluee += 1./(2*((1U<<that->blue_sBIT)-1)); |
|
} |
|
else |
|
{ |
|
that->blue = that->green = that->red; |
|
that->bluef = that->greenf = that->redf; |
|
that->bluee = that->greene = that->rede; |
|
} |
|
|
|
if ((that->colour_type & PNG_COLOR_MASK_ALPHA) || |
|
that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
that->alpha = sample_scale(that->alphaf, scale); |
|
that->alphae += 1./(2*((1U<<that->alpha_sBIT)-1)); |
|
} |
|
else |
|
{ |
|
that->alpha = scale; /* opaque */ |
|
that->alphaf = 1; /* Override this. */ |
|
that->alphae = 0; /* It's exact ;-) */ |
|
} |
|
|
|
if (sig_bits && that->alpha_sBIT < that->sample_depth) |
|
that->alpha >>= that->sample_depth - that->alpha_sBIT; |
|
} |
|
|
|
/* Static 'end' structure: */ |
|
static image_transform image_transform_end = |
|
{ |
|
"(end)", /* name */ |
|
1, /* enable */ |
|
0, /* list */ |
|
0, /* global_use */ |
|
0, /* local_use */ |
|
0, /* next */ |
|
image_transform_ini_end, |
|
image_transform_set_end, |
|
image_transform_mod_end, |
|
0 /* never called, I want it to crash if it is! */ |
|
}; |
|
|
|
/* Reader callbacks and implementations, where they differ from the standard |
|
* ones. |
|
*/ |
|
static void |
|
transform_display_init(transform_display *dp, png_modifier *pm, png_uint_32 id, |
|
const image_transform *transform_list) |
|
{ |
|
memset(dp, 0, sizeof *dp); |
|
|
|
/* Standard fields */ |
|
standard_display_init(&dp->this, &pm->this, id, do_read_interlace, |
|
pm->use_update_info); |
|
|
|
/* Parameter fields */ |
|
dp->pm = pm; |
|
dp->transform_list = transform_list; |
|
dp->max_gamma_8 = 16; |
|
|
|
/* Local variable fields */ |
|
dp->output_colour_type = 255; /* invalid */ |
|
dp->output_bit_depth = 255; /* invalid */ |
|
dp->unpacked = 0; /* not unpacked */ |
|
} |
|
|
|
static void |
|
transform_info_imp(transform_display *dp, png_structp pp, png_infop pi) |
|
{ |
|
/* Reuse the standard stuff as appropriate. */ |
|
standard_info_part1(&dp->this, pp, pi); |
|
|
|
/* Now set the list of transforms. */ |
|
dp->transform_list->set(dp->transform_list, dp, pp, pi); |
|
|
|
/* Update the info structure for these transforms: */ |
|
{ |
|
int i = dp->this.use_update_info; |
|
/* Always do one call, even if use_update_info is 0. */ |
|
do |
|
png_read_update_info(pp, pi); |
|
while (--i > 0); |
|
} |
|
|
|
/* And get the output information into the standard_display */ |
|
standard_info_part2(&dp->this, pp, pi, 1/*images*/); |
|
|
|
/* Plus the extra stuff we need for the transform tests: */ |
|
dp->output_colour_type = png_get_color_type(pp, pi); |
|
dp->output_bit_depth = png_get_bit_depth(pp, pi); |
|
|
|
/* If png_set_filler is in action then fake the output color type to include |
|
* an alpha channel where appropriate. |
|
*/ |
|
if (dp->output_bit_depth >= 8 && |
|
(dp->output_colour_type == PNG_COLOR_TYPE_RGB || |
|
dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler) |
|
dp->output_colour_type |= 4; |
|
|
|
/* Validate the combination of colour type and bit depth that we are getting |
|
* out of libpng; the semantics of something not in the PNG spec are, at |
|
* best, unclear. |
|
*/ |
|
switch (dp->output_colour_type) |
|
{ |
|
case PNG_COLOR_TYPE_PALETTE: |
|
if (dp->output_bit_depth > 8) goto error; |
|
/* FALLTHROUGH */ |
|
case PNG_COLOR_TYPE_GRAY: |
|
if (dp->output_bit_depth == 1 || dp->output_bit_depth == 2 || |
|
dp->output_bit_depth == 4) |
|
break; |
|
/* FALLTHROUGH */ |
|
default: |
|
if (dp->output_bit_depth == 8 || dp->output_bit_depth == 16) |
|
break; |
|
/* FALLTHROUGH */ |
|
error: |
|
{ |
|
char message[128]; |
|
size_t pos; |
|
|
|
pos = safecat(message, sizeof message, 0, |
|
"invalid final bit depth: colour type("); |
|
pos = safecatn(message, sizeof message, pos, dp->output_colour_type); |
|
pos = safecat(message, sizeof message, pos, ") with bit depth: "); |
|
pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); |
|
|
|
png_error(pp, message); |
|
} |
|
} |
|
|
|
/* Use a test pixel to check that the output agrees with what we expect - |
|
* this avoids running the whole test if the output is unexpected. This also |
|
* checks for internal errors. |
|
*/ |
|
{ |
|
image_pixel test_pixel; |
|
|
|
memset(&test_pixel, 0, sizeof test_pixel); |
|
test_pixel.colour_type = dp->this.colour_type; /* input */ |
|
test_pixel.bit_depth = dp->this.bit_depth; |
|
if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE) |
|
test_pixel.sample_depth = 8; |
|
else |
|
test_pixel.sample_depth = test_pixel.bit_depth; |
|
/* Don't need sBIT here, but it must be set to non-zero to avoid |
|
* arithmetic overflows. |
|
*/ |
|
test_pixel.have_tRNS = dp->this.is_transparent != 0; |
|
test_pixel.red_sBIT = test_pixel.green_sBIT = test_pixel.blue_sBIT = |
|
test_pixel.alpha_sBIT = test_pixel.sample_depth; |
|
|
|
dp->transform_list->mod(dp->transform_list, &test_pixel, pp, dp); |
|
|
|
if (test_pixel.colour_type != dp->output_colour_type) |
|
{ |
|
char message[128]; |
|
size_t pos = safecat(message, sizeof message, 0, "colour type "); |
|
|
|
pos = safecatn(message, sizeof message, pos, dp->output_colour_type); |
|
pos = safecat(message, sizeof message, pos, " expected "); |
|
pos = safecatn(message, sizeof message, pos, test_pixel.colour_type); |
|
|
|
png_error(pp, message); |
|
} |
|
|
|
if (test_pixel.bit_depth != dp->output_bit_depth) |
|
{ |
|
char message[128]; |
|
size_t pos = safecat(message, sizeof message, 0, "bit depth "); |
|
|
|
pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); |
|
pos = safecat(message, sizeof message, pos, " expected "); |
|
pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); |
|
|
|
png_error(pp, message); |
|
} |
|
|
|
/* If both bit depth and colour type are correct check the sample depth. |
|
*/ |
|
if (test_pixel.colour_type == PNG_COLOR_TYPE_PALETTE && |
|
test_pixel.sample_depth != 8) /* oops - internal error! */ |
|
png_error(pp, "pngvalid: internal: palette sample depth not 8"); |
|
else if (dp->unpacked && test_pixel.bit_depth != 8) |
|
png_error(pp, "pngvalid: internal: bad unpacked pixel depth"); |
|
else if (!dp->unpacked && test_pixel.colour_type != PNG_COLOR_TYPE_PALETTE |
|
&& test_pixel.bit_depth != test_pixel.sample_depth) |
|
{ |
|
char message[128]; |
|
size_t pos = safecat(message, sizeof message, 0, |
|
"internal: sample depth "); |
|
|
|
/* Because unless something has set 'unpacked' or the image is palette |
|
* mapped we expect the transform to keep sample depth and bit depth |
|
* the same. |
|
*/ |
|
pos = safecatn(message, sizeof message, pos, test_pixel.sample_depth); |
|
pos = safecat(message, sizeof message, pos, " expected "); |
|
pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); |
|
|
|
png_error(pp, message); |
|
} |
|
else if (test_pixel.bit_depth != dp->output_bit_depth) |
|
{ |
|
/* This could be a libpng error too; libpng has not produced what we |
|
* expect for the output bit depth. |
|
*/ |
|
char message[128]; |
|
size_t pos = safecat(message, sizeof message, 0, |
|
"internal: bit depth "); |
|
|
|
pos = safecatn(message, sizeof message, pos, dp->output_bit_depth); |
|
pos = safecat(message, sizeof message, pos, " expected "); |
|
pos = safecatn(message, sizeof message, pos, test_pixel.bit_depth); |
|
|
|
png_error(pp, message); |
|
} |
|
} |
|
} |
|
|
|
static void PNGCBAPI |
|
transform_info(png_structp pp, png_infop pi) |
|
{ |
|
transform_info_imp(voidcast(transform_display*, png_get_progressive_ptr(pp)), |
|
pp, pi); |
|
} |
|
|
|
static void |
|
transform_range_check(png_const_structp pp, unsigned int r, unsigned int g, |
|
unsigned int b, unsigned int a, unsigned int in_digitized, double in, |
|
unsigned int out, png_byte sample_depth, double err, double limit, |
|
const char *name, double digitization_error) |
|
{ |
|
/* Compare the scaled, digitzed, values of our local calculation (in+-err) |
|
* with the digitized values libpng produced; 'sample_depth' is the actual |
|
* digitization depth of the libpng output colors (the bit depth except for |
|
* palette images where it is always 8.) The check on 'err' is to detect |
|
* internal errors in pngvalid itself. |
|
*/ |
|
unsigned int max = (1U<<sample_depth)-1; |
|
double in_min = ceil((in-err)*max - digitization_error); |
|
double in_max = floor((in+err)*max + digitization_error); |
|
if (debugonly(err > limit ||) !(out >= in_min && out <= in_max)) |
|
{ |
|
char message[256]; |
|
size_t pos; |
|
|
|
pos = safecat(message, sizeof message, 0, name); |
|
pos = safecat(message, sizeof message, pos, " output value error: rgba("); |
|
pos = safecatn(message, sizeof message, pos, r); |
|
pos = safecat(message, sizeof message, pos, ","); |
|
pos = safecatn(message, sizeof message, pos, g); |
|
pos = safecat(message, sizeof message, pos, ","); |
|
pos = safecatn(message, sizeof message, pos, b); |
|
pos = safecat(message, sizeof message, pos, ","); |
|
pos = safecatn(message, sizeof message, pos, a); |
|
pos = safecat(message, sizeof message, pos, "): "); |
|
pos = safecatn(message, sizeof message, pos, out); |
|
pos = safecat(message, sizeof message, pos, " expected: "); |
|
pos = safecatn(message, sizeof message, pos, in_digitized); |
|
pos = safecat(message, sizeof message, pos, " ("); |
|
pos = safecatd(message, sizeof message, pos, (in-err)*max, 3); |
|
pos = safecat(message, sizeof message, pos, ".."); |
|
pos = safecatd(message, sizeof message, pos, (in+err)*max, 3); |
|
pos = safecat(message, sizeof message, pos, ")"); |
|
|
|
png_error(pp, message); |
|
} |
|
|
|
UNUSED(limit) |
|
} |
|
|
|
static void |
|
transform_image_validate(transform_display *dp, png_const_structp pp, |
|
png_infop pi) |
|
{ |
|
/* Constants for the loop below: */ |
|
const png_store* const ps = dp->this.ps; |
|
png_byte in_ct = dp->this.colour_type; |
|
png_byte in_bd = dp->this.bit_depth; |
|
png_uint_32 w = dp->this.w; |
|
png_uint_32 h = dp->this.h; |
|
png_byte out_ct = dp->output_colour_type; |
|
png_byte out_bd = dp->output_bit_depth; |
|
png_byte sample_depth = |
|
(png_byte)(out_ct == PNG_COLOR_TYPE_PALETTE ? 8 : out_bd); |
|
png_byte red_sBIT = dp->this.red_sBIT; |
|
png_byte green_sBIT = dp->this.green_sBIT; |
|
png_byte blue_sBIT = dp->this.blue_sBIT; |
|
png_byte alpha_sBIT = dp->this.alpha_sBIT; |
|
int have_tRNS = dp->this.is_transparent; |
|
double digitization_error; |
|
|
|
store_palette out_palette; |
|
png_uint_32 y; |
|
|
|
UNUSED(pi) |
|
|
|
/* Check for row overwrite errors */ |
|
store_image_check(dp->this.ps, pp, 0); |
|
|
|
/* Read the palette corresponding to the output if the output colour type |
|
* indicates a palette, otherwise set out_palette to garbage. |
|
*/ |
|
if (out_ct == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
/* Validate that the palette count itself has not changed - this is not |
|
* expected. |
|
*/ |
|
int npalette = (-1); |
|
|
|
(void)read_palette(out_palette, &npalette, pp, pi); |
|
if (npalette != dp->this.npalette) |
|
png_error(pp, "unexpected change in palette size"); |
|
|
|
digitization_error = .5; |
|
} |
|
else |
|
{ |
|
png_byte in_sample_depth; |
|
|
|
memset(out_palette, 0x5e, sizeof out_palette); |
|
|
|
/* use-input-precision means assume that if the input has 8 bit (or less) |
|
* samples and the output has 16 bit samples the calculations will be done |
|
* with 8 bit precision, not 16. |
|
*/ |
|
if (in_ct == PNG_COLOR_TYPE_PALETTE || in_bd < 16) |
|
in_sample_depth = 8; |
|
else |
|
in_sample_depth = in_bd; |
|
|
|
if (sample_depth != 16 || in_sample_depth > 8 || |
|
!dp->pm->calculations_use_input_precision) |
|
digitization_error = .5; |
|
|
|
/* Else calculations are at 8 bit precision, and the output actually |
|
* consists of scaled 8-bit values, so scale .5 in 8 bits to the 16 bits: |
|
*/ |
|
else |
|
digitization_error = .5 * 257; |
|
} |
|
|
|
for (y=0; y<h; ++y) |
|
{ |
|
png_const_bytep const pRow = store_image_row(ps, pp, 0, y); |
|
png_uint_32 x; |
|
|
|
/* The original, standard, row pre-transforms. */ |
|
png_byte std[STANDARD_ROWMAX]; |
|
|
|
transform_row(pp, std, in_ct, in_bd, y); |
|
|
|
/* Go through each original pixel transforming it and comparing with what |
|
* libpng did to the same pixel. |
|
*/ |
|
for (x=0; x<w; ++x) |
|
{ |
|
image_pixel in_pixel, out_pixel; |
|
unsigned int r, g, b, a; |
|
|
|
/* Find out what we think the pixel should be: */ |
|
image_pixel_init(&in_pixel, std, in_ct, in_bd, x, dp->this.palette, |
|
NULL); |
|
|
|
in_pixel.red_sBIT = red_sBIT; |
|
in_pixel.green_sBIT = green_sBIT; |
|
in_pixel.blue_sBIT = blue_sBIT; |
|
in_pixel.alpha_sBIT = alpha_sBIT; |
|
in_pixel.have_tRNS = have_tRNS != 0; |
|
|
|
/* For error detection, below. */ |
|
r = in_pixel.red; |
|
g = in_pixel.green; |
|
b = in_pixel.blue; |
|
a = in_pixel.alpha; |
|
|
|
/* This applies the transforms to the input data, including output |
|
* format operations which must be used when reading the output |
|
* pixel that libpng produces. |
|
*/ |
|
dp->transform_list->mod(dp->transform_list, &in_pixel, pp, dp); |
|
|
|
/* Read the output pixel and compare it to what we got, we don't |
|
* use the error field here, so no need to update sBIT. in_pixel |
|
* says whether we expect libpng to change the output format. |
|
*/ |
|
image_pixel_init(&out_pixel, pRow, out_ct, out_bd, x, out_palette, |
|
&in_pixel); |
|
|
|
/* We don't expect changes to the index here even if the bit depth is |
|
* changed. |
|
*/ |
|
if (in_ct == PNG_COLOR_TYPE_PALETTE && |
|
out_ct == PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
if (in_pixel.palette_index != out_pixel.palette_index) |
|
png_error(pp, "unexpected transformed palette index"); |
|
} |
|
|
|
/* Check the colours for palette images too - in fact the palette could |
|
* be separately verified itself in most cases. |
|
*/ |
|
if (in_pixel.red != out_pixel.red) |
|
transform_range_check(pp, r, g, b, a, in_pixel.red, in_pixel.redf, |
|
out_pixel.red, sample_depth, in_pixel.rede, |
|
dp->pm->limit + 1./(2*((1U<<in_pixel.red_sBIT)-1)), "red/gray", |
|
digitization_error); |
|
|
|
if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && |
|
in_pixel.green != out_pixel.green) |
|
transform_range_check(pp, r, g, b, a, in_pixel.green, |
|
in_pixel.greenf, out_pixel.green, sample_depth, in_pixel.greene, |
|
dp->pm->limit + 1./(2*((1U<<in_pixel.green_sBIT)-1)), "green", |
|
digitization_error); |
|
|
|
if ((out_ct & PNG_COLOR_MASK_COLOR) != 0 && |
|
in_pixel.blue != out_pixel.blue) |
|
transform_range_check(pp, r, g, b, a, in_pixel.blue, in_pixel.bluef, |
|
out_pixel.blue, sample_depth, in_pixel.bluee, |
|
dp->pm->limit + 1./(2*((1U<<in_pixel.blue_sBIT)-1)), "blue", |
|
digitization_error); |
|
|
|
if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0 && |
|
in_pixel.alpha != out_pixel.alpha) |
|
transform_range_check(pp, r, g, b, a, in_pixel.alpha, |
|
in_pixel.alphaf, out_pixel.alpha, sample_depth, in_pixel.alphae, |
|
dp->pm->limit + 1./(2*((1U<<in_pixel.alpha_sBIT)-1)), "alpha", |
|
digitization_error); |
|
} /* pixel (x) loop */ |
|
} /* row (y) loop */ |
|
|
|
/* Record that something was actually checked to avoid a false positive. */ |
|
dp->this.ps->validated = 1; |
|
} |
|
|
|
static void PNGCBAPI |
|
transform_end(png_structp ppIn, png_infop pi) |
|
{ |
|
png_const_structp pp = ppIn; |
|
transform_display *dp = voidcast(transform_display*, |
|
png_get_progressive_ptr(pp)); |
|
|
|
if (!dp->this.speed) |
|
transform_image_validate(dp, pp, pi); |
|
else |
|
dp->this.ps->validated = 1; |
|
} |
|
|
|
/* A single test run. */ |
|
static void |
|
transform_test(png_modifier *pmIn, png_uint_32 idIn, |
|
const image_transform* transform_listIn, const char * const name) |
|
{ |
|
transform_display d; |
|
context(&pmIn->this, fault); |
|
|
|
transform_display_init(&d, pmIn, idIn, transform_listIn); |
|
|
|
Try |
|
{ |
|
size_t pos = 0; |
|
png_structp pp; |
|
png_infop pi; |
|
char full_name[256]; |
|
|
|
/* Make sure the encoding fields are correct and enter the required |
|
* modifications. |
|
*/ |
|
transform_set_encoding(&d); |
|
|
|
/* Add any modifications required by the transform list. */ |
|
d.transform_list->ini(d.transform_list, &d); |
|
|
|
/* Add the color space information, if any, to the name. */ |
|
pos = safecat(full_name, sizeof full_name, pos, name); |
|
pos = safecat_current_encoding(full_name, sizeof full_name, pos, d.pm); |
|
|
|
/* Get a png_struct for reading the image. */ |
|
pp = set_modifier_for_read(d.pm, &pi, d.this.id, full_name); |
|
standard_palette_init(&d.this); |
|
|
|
# if 0 |
|
/* Logging (debugging only) */ |
|
{ |
|
char buffer[256]; |
|
|
|
(void)store_message(&d.pm->this, pp, buffer, sizeof buffer, 0, |
|
"running test"); |
|
|
|
fprintf(stderr, "%s\n", buffer); |
|
} |
|
# endif |
|
|
|
/* Introduce the correct read function. */ |
|
if (d.pm->this.progressive) |
|
{ |
|
/* Share the row function with the standard implementation. */ |
|
png_set_progressive_read_fn(pp, &d, transform_info, progressive_row, |
|
transform_end); |
|
|
|
/* Now feed data into the reader until we reach the end: */ |
|
modifier_progressive_read(d.pm, pp, pi); |
|
} |
|
else |
|
{ |
|
/* modifier_read expects a png_modifier* */ |
|
png_set_read_fn(pp, d.pm, modifier_read); |
|
|
|
/* Check the header values: */ |
|
png_read_info(pp, pi); |
|
|
|
/* Process the 'info' requirements. Only one image is generated */ |
|
transform_info_imp(&d, pp, pi); |
|
|
|
sequential_row(&d.this, pp, pi, -1, 0); |
|
|
|
if (!d.this.speed) |
|
transform_image_validate(&d, pp, pi); |
|
else |
|
d.this.ps->validated = 1; |
|
} |
|
|
|
modifier_reset(d.pm); |
|
} |
|
|
|
Catch(fault) |
|
{ |
|
modifier_reset(voidcast(png_modifier*,(void*)fault)); |
|
} |
|
} |
|
|
|
/* The transforms: */ |
|
#define ITSTRUCT(name) image_transform_##name |
|
#define ITDATA(name) image_transform_data_##name |
|
#define image_transform_ini image_transform_default_ini |
|
#define IT(name)\ |
|
static image_transform ITSTRUCT(name) =\ |
|
{\ |
|
#name,\ |
|
1, /*enable*/\ |
|
&PT, /*list*/\ |
|
0, /*global_use*/\ |
|
0, /*local_use*/\ |
|
0, /*next*/\ |
|
image_transform_ini,\ |
|
image_transform_png_set_##name##_set,\ |
|
image_transform_png_set_##name##_mod,\ |
|
image_transform_png_set_##name##_add\ |
|
} |
|
#define PT ITSTRUCT(end) /* stores the previous transform */ |
|
|
|
/* To save code: */ |
|
extern void image_transform_default_ini(const image_transform *this, |
|
transform_display *that); /* silence GCC warnings */ |
|
|
|
void /* private, but almost always needed */ |
|
image_transform_default_ini(const image_transform *this, |
|
transform_display *that) |
|
{ |
|
this->next->ini(this->next, that); |
|
} |
|
|
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
static int |
|
image_transform_default_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return 1; |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
/* png_set_palette_to_rgb */ |
|
static void |
|
image_transform_png_set_palette_to_rgb_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_palette_to_rgb(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_palette_to_rgb_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(that); |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_palette_to_rgb_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return colour_type == PNG_COLOR_TYPE_PALETTE; |
|
} |
|
|
|
IT(palette_to_rgb); |
|
#undef PT |
|
#define PT ITSTRUCT(palette_to_rgb) |
|
#endif /* PNG_READ_EXPAND_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
/* png_set_tRNS_to_alpha */ |
|
static void |
|
image_transform_png_set_tRNS_to_alpha_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_tRNS_to_alpha(pp); |
|
|
|
/* If there was a tRNS chunk that would get expanded and add an alpha |
|
* channel is_transparent must be updated: |
|
*/ |
|
if (that->this.has_tRNS) |
|
that->this.is_transparent = 1; |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_tRNS_to_alpha_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
#if PNG_LIBPNG_VER < 10700 |
|
/* LIBPNG BUG: this always forces palette images to RGB. */ |
|
if (that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(that); |
|
#endif |
|
|
|
/* This effectively does an 'expand' only if there is some transparency to |
|
* convert to an alpha channel. |
|
*/ |
|
if (that->have_tRNS) |
|
# if PNG_LIBPNG_VER >= 10700 |
|
if (that->colour_type != PNG_COLOR_TYPE_PALETTE && |
|
(that->colour_type & PNG_COLOR_MASK_ALPHA) == 0) |
|
# endif |
|
image_pixel_add_alpha(that, &display->this, 0/*!for background*/); |
|
|
|
#if PNG_LIBPNG_VER < 10700 |
|
/* LIBPNG BUG: otherwise libpng still expands to 8 bits! */ |
|
else |
|
{ |
|
if (that->bit_depth < 8) |
|
that->bit_depth =8; |
|
if (that->sample_depth < 8) |
|
that->sample_depth = 8; |
|
} |
|
#endif |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_tRNS_to_alpha_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* We don't know yet whether there will be a tRNS chunk, but we know that |
|
* this transformation should do nothing if there already is an alpha |
|
* channel. In addition, after the bug fix in 1.7.0, there is no longer |
|
* any action on a palette image. |
|
*/ |
|
return |
|
# if PNG_LIBPNG_VER >= 10700 |
|
colour_type != PNG_COLOR_TYPE_PALETTE && |
|
# endif |
|
(colour_type & PNG_COLOR_MASK_ALPHA) == 0; |
|
} |
|
|
|
IT(tRNS_to_alpha); |
|
#undef PT |
|
#define PT ITSTRUCT(tRNS_to_alpha) |
|
#endif /* PNG_READ_EXPAND_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
|
/* png_set_gray_to_rgb */ |
|
static void |
|
image_transform_png_set_gray_to_rgb_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_gray_to_rgb(pp); |
|
/* NOTE: this doesn't result in tRNS expansion. */ |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_gray_to_rgb_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* NOTE: we can actually pend the tRNS processing at this point because we |
|
* can correctly recognize the original pixel value even though we have |
|
* mapped the one gray channel to the three RGB ones, but in fact libpng |
|
* doesn't do this, so we don't either. |
|
*/ |
|
if ((that->colour_type & PNG_COLOR_MASK_COLOR) == 0 && that->have_tRNS) |
|
image_pixel_add_alpha(that, &display->this, 0/*!for background*/); |
|
|
|
/* Simply expand the bit depth and alter the colour type as required. */ |
|
if (that->colour_type == PNG_COLOR_TYPE_GRAY) |
|
{ |
|
/* RGB images have a bit depth at least equal to '8' */ |
|
if (that->bit_depth < 8) |
|
that->sample_depth = that->bit_depth = 8; |
|
|
|
/* And just changing the colour type works here because the green and blue |
|
* channels are being maintained in lock-step with the red/gray: |
|
*/ |
|
that->colour_type = PNG_COLOR_TYPE_RGB; |
|
} |
|
|
|
else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_gray_to_rgb_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return (colour_type & PNG_COLOR_MASK_COLOR) == 0; |
|
} |
|
|
|
IT(gray_to_rgb); |
|
#undef PT |
|
#define PT ITSTRUCT(gray_to_rgb) |
|
#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
/* png_set_expand */ |
|
static void |
|
image_transform_png_set_expand_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_expand(pp); |
|
|
|
if (that->this.has_tRNS) |
|
that->this.is_transparent = 1; |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_expand_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* The general expand case depends on what the colour type is: */ |
|
if (that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(that); |
|
else if (that->bit_depth < 8) /* grayscale */ |
|
that->sample_depth = that->bit_depth = 8; |
|
|
|
if (that->have_tRNS) |
|
image_pixel_add_alpha(that, &display->this, 0/*!for background*/); |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_expand_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* 'expand' should do nothing for RGBA or GA input - no tRNS and the bit |
|
* depth is at least 8 already. |
|
*/ |
|
return (colour_type & PNG_COLOR_MASK_ALPHA) == 0; |
|
} |
|
|
|
IT(expand); |
|
#undef PT |
|
#define PT ITSTRUCT(expand) |
|
#endif /* PNG_READ_EXPAND_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_EXPAND_SUPPORTED |
|
/* png_set_expand_gray_1_2_4_to_8 |
|
* Pre 1.7.0 LIBPNG BUG: this just does an 'expand' |
|
*/ |
|
static void |
|
image_transform_png_set_expand_gray_1_2_4_to_8_set( |
|
const image_transform *this, transform_display *that, png_structp pp, |
|
png_infop pi) |
|
{ |
|
png_set_expand_gray_1_2_4_to_8(pp); |
|
/* NOTE: don't expect this to expand tRNS */ |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_expand_gray_1_2_4_to_8_mod( |
|
const image_transform *this, image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
#if PNG_LIBPNG_VER < 10700 |
|
image_transform_png_set_expand_mod(this, that, pp, display); |
|
#else |
|
/* Only expand grayscale of bit depth less than 8: */ |
|
if (that->colour_type == PNG_COLOR_TYPE_GRAY && |
|
that->bit_depth < 8) |
|
that->sample_depth = that->bit_depth = 8; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
#endif /* 1.7 or later */ |
|
} |
|
|
|
static int |
|
image_transform_png_set_expand_gray_1_2_4_to_8_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
#if PNG_LIBPNG_VER < 10700 |
|
return image_transform_png_set_expand_add(this, that, colour_type, |
|
bit_depth); |
|
#else |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* This should do nothing unless the color type is gray and the bit depth is |
|
* less than 8: |
|
*/ |
|
return colour_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8; |
|
#endif /* 1.7 or later */ |
|
} |
|
|
|
IT(expand_gray_1_2_4_to_8); |
|
#undef PT |
|
#define PT ITSTRUCT(expand_gray_1_2_4_to_8) |
|
#endif /* PNG_READ_EXPAND_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
/* png_set_expand_16 */ |
|
static void |
|
image_transform_png_set_expand_16_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_expand_16(pp); |
|
|
|
/* NOTE: prior to 1.7 libpng does SET_EXPAND as well, so tRNS is expanded. */ |
|
# if PNG_LIBPNG_VER < 10700 |
|
if (that->this.has_tRNS) |
|
that->this.is_transparent = 1; |
|
# endif |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_expand_16_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* Expect expand_16 to expand everything to 16 bits as a result of also |
|
* causing 'expand' to happen. |
|
*/ |
|
if (that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(that); |
|
|
|
if (that->have_tRNS) |
|
image_pixel_add_alpha(that, &display->this, 0/*!for background*/); |
|
|
|
if (that->bit_depth < 16) |
|
that->sample_depth = that->bit_depth = 16; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_expand_16_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* expand_16 does something unless the bit depth is already 16. */ |
|
return bit_depth < 16; |
|
} |
|
|
|
IT(expand_16); |
|
#undef PT |
|
#define PT ITSTRUCT(expand_16) |
|
#endif /* PNG_READ_EXPAND_16_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED /* API added in 1.5.4 */ |
|
/* png_set_scale_16 */ |
|
static void |
|
image_transform_png_set_scale_16_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_scale_16(pp); |
|
# if PNG_LIBPNG_VER < 10700 |
|
/* libpng will limit the gamma table size: */ |
|
that->max_gamma_8 = PNG_MAX_GAMMA_8; |
|
# endif |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_scale_16_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth == 16) |
|
{ |
|
that->sample_depth = that->bit_depth = 8; |
|
if (that->red_sBIT > 8) that->red_sBIT = 8; |
|
if (that->green_sBIT > 8) that->green_sBIT = 8; |
|
if (that->blue_sBIT > 8) that->blue_sBIT = 8; |
|
if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_scale_16_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth > 8; |
|
} |
|
|
|
IT(scale_16); |
|
#undef PT |
|
#define PT ITSTRUCT(scale_16) |
|
#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */ |
|
|
|
#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */ |
|
/* png_set_strip_16 */ |
|
static void |
|
image_transform_png_set_strip_16_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_strip_16(pp); |
|
# if PNG_LIBPNG_VER < 10700 |
|
/* libpng will limit the gamma table size: */ |
|
that->max_gamma_8 = PNG_MAX_GAMMA_8; |
|
# endif |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_strip_16_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth == 16) |
|
{ |
|
that->sample_depth = that->bit_depth = 8; |
|
if (that->red_sBIT > 8) that->red_sBIT = 8; |
|
if (that->green_sBIT > 8) that->green_sBIT = 8; |
|
if (that->blue_sBIT > 8) that->blue_sBIT = 8; |
|
if (that->alpha_sBIT > 8) that->alpha_sBIT = 8; |
|
|
|
/* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this |
|
* configuration option is set. From 1.5.4 the flag is never set and the |
|
* 'scale' API (above) must be used. |
|
*/ |
|
# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED |
|
# if PNG_LIBPNG_VER >= 10504 |
|
# error PNG_READ_ACCURATE_SCALE should not be set |
|
# endif |
|
|
|
/* The strip 16 algorithm drops the low 8 bits rather than calculating |
|
* 1/257, so we need to adjust the permitted errors appropriately: |
|
* Notice that this is only relevant prior to the addition of the |
|
* png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!) |
|
*/ |
|
{ |
|
const double d = (255-128.5)/65535; |
|
that->rede += d; |
|
that->greene += d; |
|
that->bluee += d; |
|
that->alphae += d; |
|
} |
|
# endif |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_strip_16_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth > 8; |
|
} |
|
|
|
IT(strip_16); |
|
#undef PT |
|
#define PT ITSTRUCT(strip_16) |
|
#endif /* PNG_READ_16_TO_8_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
|
/* png_set_strip_alpha */ |
|
static void |
|
image_transform_png_set_strip_alpha_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_strip_alpha(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_strip_alpha_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_GRAY; |
|
else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_RGB; |
|
|
|
that->have_tRNS = 0; |
|
that->alphaf = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_strip_alpha_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return (colour_type & PNG_COLOR_MASK_ALPHA) != 0; |
|
} |
|
|
|
IT(strip_alpha); |
|
#undef PT |
|
#define PT ITSTRUCT(strip_alpha) |
|
#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
|
/* png_set_rgb_to_gray(png_structp, int err_action, double red, double green) |
|
* png_set_rgb_to_gray_fixed(png_structp, int err_action, png_fixed_point red, |
|
* png_fixed_point green) |
|
* png_get_rgb_to_gray_status |
|
* |
|
* The 'default' test here uses values known to be used inside libpng prior to |
|
* 1.7.0: |
|
* |
|
* red: 6968 |
|
* green: 23434 |
|
* blue: 2366 |
|
* |
|
* These values are being retained for compatibility, along with the somewhat |
|
* broken truncation calculation in the fast-and-inaccurate code path. Older |
|
* versions of libpng will fail the accuracy tests below because they use the |
|
* truncation algorithm everywhere. |
|
*/ |
|
#define data ITDATA(rgb_to_gray) |
|
static struct |
|
{ |
|
double gamma; /* File gamma to use in processing */ |
|
|
|
/* The following are the parameters for png_set_rgb_to_gray: */ |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
double red_to_set; |
|
double green_to_set; |
|
# else |
|
png_fixed_point red_to_set; |
|
png_fixed_point green_to_set; |
|
# endif |
|
|
|
/* The actual coefficients: */ |
|
double red_coefficient; |
|
double green_coefficient; |
|
double blue_coefficient; |
|
|
|
/* Set if the coeefficients have been overridden. */ |
|
int coefficients_overridden; |
|
} data; |
|
|
|
#undef image_transform_ini |
|
#define image_transform_ini image_transform_png_set_rgb_to_gray_ini |
|
static void |
|
image_transform_png_set_rgb_to_gray_ini(const image_transform *this, |
|
transform_display *that) |
|
{ |
|
png_modifier *pm = that->pm; |
|
const color_encoding *e = pm->current_encoding; |
|
|
|
UNUSED(this) |
|
|
|
/* Since we check the encoding this flag must be set: */ |
|
pm->test_uses_encoding = 1; |
|
|
|
/* If 'e' is not NULL chromaticity information is present and either a cHRM |
|
* or an sRGB chunk will be inserted. |
|
*/ |
|
if (e != 0) |
|
{ |
|
/* Coefficients come from the encoding, but may need to be normalized to a |
|
* white point Y of 1.0 |
|
*/ |
|
const double whiteY = e->red.Y + e->green.Y + e->blue.Y; |
|
|
|
data.red_coefficient = e->red.Y; |
|
data.green_coefficient = e->green.Y; |
|
data.blue_coefficient = e->blue.Y; |
|
|
|
if (whiteY != 1) |
|
{ |
|
data.red_coefficient /= whiteY; |
|
data.green_coefficient /= whiteY; |
|
data.blue_coefficient /= whiteY; |
|
} |
|
} |
|
|
|
else |
|
{ |
|
/* The default (built in) coeffcients, as above: */ |
|
# if PNG_LIBPNG_VER < 10700 |
|
data.red_coefficient = 6968 / 32768.; |
|
data.green_coefficient = 23434 / 32768.; |
|
data.blue_coefficient = 2366 / 32768.; |
|
# else |
|
data.red_coefficient = .2126; |
|
data.green_coefficient = .7152; |
|
data.blue_coefficient = .0722; |
|
# endif |
|
} |
|
|
|
data.gamma = pm->current_gamma; |
|
|
|
/* If not set then the calculations assume linear encoding (implicitly): */ |
|
if (data.gamma == 0) |
|
data.gamma = 1; |
|
|
|
/* The arguments to png_set_rgb_to_gray can override the coefficients implied |
|
* by the color space encoding. If doing exhaustive checks do the override |
|
* in each case, otherwise do it randomly. |
|
*/ |
|
if (pm->test_exhaustive) |
|
{ |
|
/* First time in coefficients_overridden is 0, the following sets it to 1, |
|
* so repeat if it is set. If a test fails this may mean we subsequently |
|
* skip a non-override test, ignore that. |
|
*/ |
|
data.coefficients_overridden = !data.coefficients_overridden; |
|
pm->repeat = data.coefficients_overridden != 0; |
|
} |
|
|
|
else |
|
data.coefficients_overridden = random_choice(); |
|
|
|
if (data.coefficients_overridden) |
|
{ |
|
/* These values override the color encoding defaults, simply use random |
|
* numbers. |
|
*/ |
|
png_uint_32 ru; |
|
double total; |
|
|
|
ru = random_u32(); |
|
data.green_coefficient = total = (ru & 0xffff) / 65535.; |
|
ru >>= 16; |
|
data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.; |
|
total += data.red_coefficient; |
|
data.blue_coefficient = 1 - total; |
|
|
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
data.red_to_set = data.red_coefficient; |
|
data.green_to_set = data.green_coefficient; |
|
# else |
|
data.red_to_set = fix(data.red_coefficient); |
|
data.green_to_set = fix(data.green_coefficient); |
|
# endif |
|
|
|
/* The following just changes the error messages: */ |
|
pm->encoding_ignored = 1; |
|
} |
|
|
|
else |
|
{ |
|
data.red_to_set = -1; |
|
data.green_to_set = -1; |
|
} |
|
|
|
/* Adjust the error limit in the png_modifier because of the larger errors |
|
* produced in the digitization during the gamma handling. |
|
*/ |
|
if (data.gamma != 1) /* Use gamma tables */ |
|
{ |
|
if (that->this.bit_depth == 16 || pm->assume_16_bit_calculations) |
|
{ |
|
/* The computations have the form: |
|
* |
|
* r * rc + g * gc + b * bc |
|
* |
|
* Each component of which is +/-1/65535 from the gamma_to_1 table |
|
* lookup, resulting in a base error of +/-6. The gamma_from_1 |
|
* conversion adds another +/-2 in the 16-bit case and |
|
* +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case. |
|
*/ |
|
# if PNG_LIBPNG_VER < 10700 |
|
if (that->this.bit_depth < 16) |
|
that->max_gamma_8 = PNG_MAX_GAMMA_8; |
|
# endif |
|
that->pm->limit += pow( |
|
(that->this.bit_depth == 16 || that->max_gamma_8 > 14 ? |
|
8. : |
|
6. + (1<<(15-that->max_gamma_8)) |
|
)/65535, data.gamma); |
|
} |
|
|
|
else |
|
{ |
|
/* Rounding to 8 bits in the linear space causes massive errors which |
|
* will trigger the error check in transform_range_check. Fix that |
|
* here by taking the gamma encoding into account. |
|
* |
|
* When DIGITIZE is set because a pre-1.7 version of libpng is being |
|
* tested allow a bigger slack. |
|
* |
|
* NOTE: this number only affects the internal limit check in pngvalid, |
|
* it has no effect on the limits applied to the libpng values. |
|
*/ |
|
#if DIGITIZE |
|
that->pm->limit += pow( 2.0/255, data.gamma); |
|
#else |
|
that->pm->limit += pow( 1.0/255, data.gamma); |
|
#endif |
|
} |
|
} |
|
|
|
else |
|
{ |
|
/* With no gamma correction a large error comes from the truncation of the |
|
* calculation in the 8 bit case, allow for that here. |
|
*/ |
|
if (that->this.bit_depth != 16 && !pm->assume_16_bit_calculations) |
|
that->pm->limit += 4E-3; |
|
} |
|
} |
|
|
|
static void |
|
image_transform_png_set_rgb_to_gray_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
int error_action = 1; /* no error, no defines in png.h */ |
|
|
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_rgb_to_gray(pp, error_action, data.red_to_set, data.green_to_set); |
|
# else |
|
png_set_rgb_to_gray_fixed(pp, error_action, data.red_to_set, |
|
data.green_to_set); |
|
# endif |
|
|
|
# ifdef PNG_READ_cHRM_SUPPORTED |
|
if (that->pm->current_encoding != 0) |
|
{ |
|
/* We have an encoding so a cHRM chunk may have been set; if so then |
|
* check that the libpng APIs give the correct (X,Y,Z) values within |
|
* some margin of error for the round trip through the chromaticity |
|
* form. |
|
*/ |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
# define API_function png_get_cHRM_XYZ |
|
# define API_form "FP" |
|
# define API_type double |
|
# define API_cvt(x) (x) |
|
# else |
|
# define API_function png_get_cHRM_XYZ_fixed |
|
# define API_form "fixed" |
|
# define API_type png_fixed_point |
|
# define API_cvt(x) ((double)(x)/PNG_FP_1) |
|
# endif |
|
|
|
API_type rX, gX, bX; |
|
API_type rY, gY, bY; |
|
API_type rZ, gZ, bZ; |
|
|
|
if ((API_function(pp, pi, &rX, &rY, &rZ, &gX, &gY, &gZ, &bX, &bY, &bZ) |
|
& PNG_INFO_cHRM) != 0) |
|
{ |
|
double maxe; |
|
const char *el; |
|
color_encoding e, o; |
|
|
|
/* Expect libpng to return a normalized result, but the original |
|
* color space encoding may not be normalized. |
|
*/ |
|
modifier_current_encoding(that->pm, &o); |
|
normalize_color_encoding(&o); |
|
|
|
/* Sanity check the pngvalid code - the coefficients should match |
|
* the normalized Y values of the encoding unless they were |
|
* overridden. |
|
*/ |
|
if (data.red_to_set == -1 && data.green_to_set == -1 && |
|
(fabs(o.red.Y - data.red_coefficient) > DBL_EPSILON || |
|
fabs(o.green.Y - data.green_coefficient) > DBL_EPSILON || |
|
fabs(o.blue.Y - data.blue_coefficient) > DBL_EPSILON)) |
|
png_error(pp, "internal pngvalid cHRM coefficient error"); |
|
|
|
/* Generate a colour space encoding. */ |
|
e.gamma = o.gamma; /* not used */ |
|
e.red.X = API_cvt(rX); |
|
e.red.Y = API_cvt(rY); |
|
e.red.Z = API_cvt(rZ); |
|
e.green.X = API_cvt(gX); |
|
e.green.Y = API_cvt(gY); |
|
e.green.Z = API_cvt(gZ); |
|
e.blue.X = API_cvt(bX); |
|
e.blue.Y = API_cvt(bY); |
|
e.blue.Z = API_cvt(bZ); |
|
|
|
/* This should match the original one from the png_modifier, within |
|
* the range permitted by the libpng fixed point representation. |
|
*/ |
|
maxe = 0; |
|
el = "-"; /* Set to element name with error */ |
|
|
|
# define CHECK(col,x)\ |
|
{\ |
|
double err = fabs(o.col.x - e.col.x);\ |
|
if (err > maxe)\ |
|
{\ |
|
maxe = err;\ |
|
el = #col "(" #x ")";\ |
|
}\ |
|
} |
|
|
|
CHECK(red,X) |
|
CHECK(red,Y) |
|
CHECK(red,Z) |
|
CHECK(green,X) |
|
CHECK(green,Y) |
|
CHECK(green,Z) |
|
CHECK(blue,X) |
|
CHECK(blue,Y) |
|
CHECK(blue,Z) |
|
|
|
/* Here in both fixed and floating cases to check the values read |
|
* from the cHRm chunk. PNG uses fixed point in the cHRM chunk, so |
|
* we can't expect better than +/-.5E-5 on the result, allow 1E-5. |
|
*/ |
|
if (maxe >= 1E-5) |
|
{ |
|
size_t pos = 0; |
|
char buffer[256]; |
|
|
|
pos = safecat(buffer, sizeof buffer, pos, API_form); |
|
pos = safecat(buffer, sizeof buffer, pos, " cHRM "); |
|
pos = safecat(buffer, sizeof buffer, pos, el); |
|
pos = safecat(buffer, sizeof buffer, pos, " error: "); |
|
pos = safecatd(buffer, sizeof buffer, pos, maxe, 7); |
|
pos = safecat(buffer, sizeof buffer, pos, " "); |
|
/* Print the color space without the gamma value: */ |
|
pos = safecat_color_encoding(buffer, sizeof buffer, pos, &o, 0); |
|
pos = safecat(buffer, sizeof buffer, pos, " -> "); |
|
pos = safecat_color_encoding(buffer, sizeof buffer, pos, &e, 0); |
|
|
|
png_error(pp, buffer); |
|
} |
|
} |
|
} |
|
# endif /* READ_cHRM */ |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_rgb_to_gray_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if ((that->colour_type & PNG_COLOR_MASK_COLOR) != 0) |
|
{ |
|
double gray, err; |
|
|
|
# if PNG_LIBPNG_VER < 10700 |
|
if (that->colour_type == PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_convert_PLTE(that); |
|
# endif |
|
|
|
/* Image now has RGB channels... */ |
|
# if DIGITIZE |
|
{ |
|
png_modifier *pm = display->pm; |
|
unsigned int sample_depth = that->sample_depth; |
|
unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 : |
|
sample_depth); |
|
unsigned int gamma_depth = |
|
(sample_depth == 16 ? |
|
display->max_gamma_8 : |
|
(pm->assume_16_bit_calculations ? |
|
display->max_gamma_8 : |
|
sample_depth)); |
|
int isgray; |
|
double r, g, b; |
|
double rlo, rhi, glo, ghi, blo, bhi, graylo, grayhi; |
|
|
|
/* Do this using interval arithmetic, otherwise it is too difficult to |
|
* handle the errors correctly. |
|
* |
|
* To handle the gamma correction work out the upper and lower bounds |
|
* of the digitized value. Assume rounding here - normally the values |
|
* will be identical after this operation if there is only one |
|
* transform, feel free to delete the png_error checks on this below in |
|
* the future (this is just me trying to ensure it works!) |
|
* |
|
* Interval arithmetic is exact, but to implement it it must be |
|
* possible to control the floating point implementation rounding mode. |
|
* This cannot be done in ANSI-C, so instead I reduce the 'lo' values |
|
* by DBL_EPSILON and increase the 'hi' values by the same. |
|
*/ |
|
# define DD(v,d,r) (digitize(v*(1-DBL_EPSILON), d, r) * (1-DBL_EPSILON)) |
|
# define DU(v,d,r) (digitize(v*(1+DBL_EPSILON), d, r) * (1+DBL_EPSILON)) |
|
|
|
r = rlo = rhi = that->redf; |
|
rlo -= that->rede; |
|
rlo = DD(rlo, calc_depth, 1/*round*/); |
|
rhi += that->rede; |
|
rhi = DU(rhi, calc_depth, 1/*round*/); |
|
|
|
g = glo = ghi = that->greenf; |
|
glo -= that->greene; |
|
glo = DD(glo, calc_depth, 1/*round*/); |
|
ghi += that->greene; |
|
ghi = DU(ghi, calc_depth, 1/*round*/); |
|
|
|
b = blo = bhi = that->bluef; |
|
blo -= that->bluee; |
|
blo = DD(blo, calc_depth, 1/*round*/); |
|
bhi += that->bluee; |
|
bhi = DU(bhi, calc_depth, 1/*round*/); |
|
|
|
isgray = r==g && g==b; |
|
|
|
if (data.gamma != 1) |
|
{ |
|
const double power = 1/data.gamma; |
|
const double abse = .5/(sample_depth == 16 ? 65535 : 255); |
|
|
|
/* If a gamma calculation is done it is done using lookup tables of |
|
* precision gamma_depth, so the already digitized value above may |
|
* need to be further digitized here. |
|
*/ |
|
if (gamma_depth != calc_depth) |
|
{ |
|
rlo = DD(rlo, gamma_depth, 0/*truncate*/); |
|
rhi = DU(rhi, gamma_depth, 0/*truncate*/); |
|
glo = DD(glo, gamma_depth, 0/*truncate*/); |
|
ghi = DU(ghi, gamma_depth, 0/*truncate*/); |
|
blo = DD(blo, gamma_depth, 0/*truncate*/); |
|
bhi = DU(bhi, gamma_depth, 0/*truncate*/); |
|
} |
|
|
|
/* 'abse' is the error in the gamma table calculation itself. */ |
|
r = pow(r, power); |
|
rlo = DD(pow(rlo, power)-abse, calc_depth, 1); |
|
rhi = DU(pow(rhi, power)+abse, calc_depth, 1); |
|
|
|
g = pow(g, power); |
|
glo = DD(pow(glo, power)-abse, calc_depth, 1); |
|
ghi = DU(pow(ghi, power)+abse, calc_depth, 1); |
|
|
|
b = pow(b, power); |
|
blo = DD(pow(blo, power)-abse, calc_depth, 1); |
|
bhi = DU(pow(bhi, power)+abse, calc_depth, 1); |
|
} |
|
|
|
/* Now calculate the actual gray values. Although the error in the |
|
* coefficients depends on whether they were specified on the command |
|
* line (in which case truncation to 15 bits happened) or not (rounding |
|
* was used) the maximum error in an individual coefficient is always |
|
* 2/32768, because even in the rounding case the requirement that |
|
* coefficients add up to 32768 can cause a larger rounding error. |
|
* |
|
* The only time when rounding doesn't occur in 1.5.5 and later is when |
|
* the non-gamma code path is used for less than 16 bit data. |
|
*/ |
|
gray = r * data.red_coefficient + g * data.green_coefficient + |
|
b * data.blue_coefficient; |
|
|
|
{ |
|
int do_round = data.gamma != 1 || calc_depth == 16; |
|
const double ce = 2. / 32768; |
|
|
|
graylo = DD(rlo * (data.red_coefficient-ce) + |
|
glo * (data.green_coefficient-ce) + |
|
blo * (data.blue_coefficient-ce), calc_depth, do_round); |
|
if (graylo > gray) /* always accept the right answer */ |
|
graylo = gray; |
|
|
|
grayhi = DU(rhi * (data.red_coefficient+ce) + |
|
ghi * (data.green_coefficient+ce) + |
|
bhi * (data.blue_coefficient+ce), calc_depth, do_round); |
|
if (grayhi < gray) |
|
grayhi = gray; |
|
} |
|
|
|
/* And invert the gamma. */ |
|
if (data.gamma != 1) |
|
{ |
|
const double power = data.gamma; |
|
|
|
/* And this happens yet again, shifting the values once more. */ |
|
if (gamma_depth != sample_depth) |
|
{ |
|
rlo = DD(rlo, gamma_depth, 0/*truncate*/); |
|
rhi = DU(rhi, gamma_depth, 0/*truncate*/); |
|
glo = DD(glo, gamma_depth, 0/*truncate*/); |
|
ghi = DU(ghi, gamma_depth, 0/*truncate*/); |
|
blo = DD(blo, gamma_depth, 0/*truncate*/); |
|
bhi = DU(bhi, gamma_depth, 0/*truncate*/); |
|
} |
|
|
|
gray = pow(gray, power); |
|
graylo = DD(pow(graylo, power), sample_depth, 1); |
|
grayhi = DU(pow(grayhi, power), sample_depth, 1); |
|
} |
|
|
|
# undef DD |
|
# undef DU |
|
|
|
/* Now the error can be calculated. |
|
* |
|
* If r==g==b because there is no overall gamma correction libpng |
|
* currently preserves the original value. |
|
*/ |
|
if (isgray) |
|
err = (that->rede + that->greene + that->bluee)/3; |
|
|
|
else |
|
{ |
|
err = fabs(grayhi-gray); |
|
|
|
if (fabs(gray - graylo) > err) |
|
err = fabs(graylo-gray); |
|
|
|
#if !RELEASE_BUILD |
|
/* Check that this worked: */ |
|
if (err > pm->limit) |
|
{ |
|
size_t pos = 0; |
|
char buffer[128]; |
|
|
|
pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); |
|
pos = safecatd(buffer, sizeof buffer, pos, err, 6); |
|
pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); |
|
pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); |
|
png_warning(pp, buffer); |
|
pm->limit = err; |
|
} |
|
#endif /* !RELEASE_BUILD */ |
|
} |
|
} |
|
# else /* !DIGITIZE */ |
|
{ |
|
double r = that->redf; |
|
double re = that->rede; |
|
double g = that->greenf; |
|
double ge = that->greene; |
|
double b = that->bluef; |
|
double be = that->bluee; |
|
|
|
# if PNG_LIBPNG_VER < 10700 |
|
/* The true gray case involves no math in earlier versions (not |
|
* true, there was some if gamma correction was happening too.) |
|
*/ |
|
if (r == g && r == b) |
|
{ |
|
gray = r; |
|
err = re; |
|
if (err < ge) err = ge; |
|
if (err < be) err = be; |
|
} |
|
|
|
else |
|
# endif /* before 1.7 */ |
|
if (data.gamma == 1) |
|
{ |
|
/* There is no need to do the conversions to and from linear space, |
|
* so the calculation should be a lot more accurate. There is a |
|
* built in error in the coefficients because they only have 15 bits |
|
* and are adjusted to make sure they add up to 32768. This |
|
* involves a integer calculation with truncation of the form: |
|
* |
|
* ((int)(coefficient * 100000) * 32768)/100000 |
|
* |
|
* This is done to the red and green coefficients (the ones |
|
* provided to the API) then blue is calculated from them so the |
|
* result adds up to 32768. In the worst case this can result in |
|
* a -1 error in red and green and a +2 error in blue. Consequently |
|
* the worst case in the calculation below is 2/32768 error. |
|
* |
|
* TODO: consider fixing this in libpng by rounding the calculation |
|
* limiting the error to 1/32768. |
|
* |
|
* Handling this by adding 2/32768 here avoids needing to increase |
|
* the global error limits to take this into account.) |
|
*/ |
|
gray = r * data.red_coefficient + g * data.green_coefficient + |
|
b * data.blue_coefficient; |
|
err = re * data.red_coefficient + ge * data.green_coefficient + |
|
be * data.blue_coefficient + 2./32768 + gray * 5 * DBL_EPSILON; |
|
} |
|
|
|
else |
|
{ |
|
/* The calculation happens in linear space, and this produces much |
|
* wider errors in the encoded space. These are handled here by |
|
* factoring the errors in to the calculation. There are two table |
|
* lookups in the calculation and each introduces a quantization |
|
* error defined by the table size. |
|
*/ |
|
png_modifier *pm = display->pm; |
|
double in_qe = (that->sample_depth > 8 ? .5/65535 : .5/255); |
|
double out_qe = (that->sample_depth > 8 ? .5/65535 : |
|
(pm->assume_16_bit_calculations ? .5/(1<<display->max_gamma_8) : |
|
.5/255)); |
|
double rhi, ghi, bhi, grayhi; |
|
double g1 = 1/data.gamma; |
|
|
|
rhi = r + re + in_qe; if (rhi > 1) rhi = 1; |
|
r -= re + in_qe; if (r < 0) r = 0; |
|
ghi = g + ge + in_qe; if (ghi > 1) ghi = 1; |
|
g -= ge + in_qe; if (g < 0) g = 0; |
|
bhi = b + be + in_qe; if (bhi > 1) bhi = 1; |
|
b -= be + in_qe; if (b < 0) b = 0; |
|
|
|
r = pow(r, g1)*(1-DBL_EPSILON); rhi = pow(rhi, g1)*(1+DBL_EPSILON); |
|
g = pow(g, g1)*(1-DBL_EPSILON); ghi = pow(ghi, g1)*(1+DBL_EPSILON); |
|
b = pow(b, g1)*(1-DBL_EPSILON); bhi = pow(bhi, g1)*(1+DBL_EPSILON); |
|
|
|
/* Work out the lower and upper bounds for the gray value in the |
|
* encoded space, then work out an average and error. Remove the |
|
* previously added input quantization error at this point. |
|
*/ |
|
gray = r * data.red_coefficient + g * data.green_coefficient + |
|
b * data.blue_coefficient - 2./32768 - out_qe; |
|
if (gray <= 0) |
|
gray = 0; |
|
else |
|
{ |
|
gray *= (1 - 6 * DBL_EPSILON); |
|
gray = pow(gray, data.gamma) * (1-DBL_EPSILON); |
|
} |
|
|
|
grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient + |
|
bhi * data.blue_coefficient + 2./32768 + out_qe; |
|
grayhi *= (1 + 6 * DBL_EPSILON); |
|
if (grayhi >= 1) |
|
grayhi = 1; |
|
else |
|
grayhi = pow(grayhi, data.gamma) * (1+DBL_EPSILON); |
|
|
|
err = (grayhi - gray) / 2; |
|
gray = (grayhi + gray) / 2; |
|
|
|
if (err <= in_qe) |
|
err = gray * DBL_EPSILON; |
|
|
|
else |
|
err -= in_qe; |
|
|
|
#if !RELEASE_BUILD |
|
/* Validate that the error is within limits (this has caused |
|
* problems before, it's much easier to detect them here.) |
|
*/ |
|
if (err > pm->limit) |
|
{ |
|
size_t pos = 0; |
|
char buffer[128]; |
|
|
|
pos = safecat(buffer, sizeof buffer, pos, "rgb_to_gray error "); |
|
pos = safecatd(buffer, sizeof buffer, pos, err, 6); |
|
pos = safecat(buffer, sizeof buffer, pos, " exceeds limit "); |
|
pos = safecatd(buffer, sizeof buffer, pos, pm->limit, 6); |
|
png_warning(pp, buffer); |
|
pm->limit = err; |
|
} |
|
#endif /* !RELEASE_BUILD */ |
|
} |
|
} |
|
# endif /* !DIGITIZE */ |
|
|
|
that->bluef = that->greenf = that->redf = gray; |
|
that->bluee = that->greene = that->rede = err; |
|
|
|
/* The sBIT is the minimum of the three colour channel sBITs. */ |
|
if (that->red_sBIT > that->green_sBIT) |
|
that->red_sBIT = that->green_sBIT; |
|
if (that->red_sBIT > that->blue_sBIT) |
|
that->red_sBIT = that->blue_sBIT; |
|
that->blue_sBIT = that->green_sBIT = that->red_sBIT; |
|
|
|
/* And remove the colour bit in the type: */ |
|
if (that->colour_type == PNG_COLOR_TYPE_RGB) |
|
that->colour_type = PNG_COLOR_TYPE_GRAY; |
|
else if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_rgb_to_gray_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return (colour_type & PNG_COLOR_MASK_COLOR) != 0; |
|
} |
|
|
|
#undef data |
|
IT(rgb_to_gray); |
|
#undef PT |
|
#define PT ITSTRUCT(rgb_to_gray) |
|
#undef image_transform_ini |
|
#define image_transform_ini image_transform_default_ini |
|
#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
/* png_set_background(png_structp, png_const_color_16p background_color, |
|
* int background_gamma_code, int need_expand, double background_gamma) |
|
* png_set_background_fixed(png_structp, png_const_color_16p background_color, |
|
* int background_gamma_code, int need_expand, |
|
* png_fixed_point background_gamma) |
|
* |
|
* This ignores the gamma (at present.) |
|
*/ |
|
#define data ITDATA(background) |
|
static image_pixel data; |
|
|
|
static void |
|
image_transform_png_set_background_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_byte colour_type, bit_depth; |
|
png_byte random_bytes[8]; /* 8 bytes - 64 bits - the biggest pixel */ |
|
int expand; |
|
png_color_16 back; |
|
|
|
/* We need a background colour, because we don't know exactly what transforms |
|
* have been set we have to supply the colour in the original file format and |
|
* so we need to know what that is! The background colour is stored in the |
|
* transform_display. |
|
*/ |
|
R8(random_bytes); |
|
|
|
/* Read the random value, for colour type 3 the background colour is actually |
|
* expressed as a 24bit rgb, not an index. |
|
*/ |
|
colour_type = that->this.colour_type; |
|
if (colour_type == 3) |
|
{ |
|
colour_type = PNG_COLOR_TYPE_RGB; |
|
bit_depth = 8; |
|
expand = 0; /* passing in an RGB not a pixel index */ |
|
} |
|
|
|
else |
|
{ |
|
if (that->this.has_tRNS) |
|
that->this.is_transparent = 1; |
|
|
|
bit_depth = that->this.bit_depth; |
|
expand = 1; |
|
} |
|
|
|
image_pixel_init(&data, random_bytes, colour_type, |
|
bit_depth, 0/*x*/, 0/*unused: palette*/, NULL/*format*/); |
|
|
|
/* Extract the background colour from this image_pixel, but make sure the |
|
* unused fields of 'back' are garbage. |
|
*/ |
|
R8(back); |
|
|
|
if (colour_type & PNG_COLOR_MASK_COLOR) |
|
{ |
|
back.red = (png_uint_16)data.red; |
|
back.green = (png_uint_16)data.green; |
|
back.blue = (png_uint_16)data.blue; |
|
} |
|
|
|
else |
|
back.gray = (png_uint_16)data.red; |
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_background(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); |
|
#else |
|
png_set_background_fixed(pp, &back, PNG_BACKGROUND_GAMMA_FILE, expand, 0); |
|
#endif |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_background_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* Check for tRNS first: */ |
|
if (that->have_tRNS && that->colour_type != PNG_COLOR_TYPE_PALETTE) |
|
image_pixel_add_alpha(that, &display->this, 1/*for background*/); |
|
|
|
/* This is only necessary if the alpha value is less than 1. */ |
|
if (that->alphaf < 1) |
|
{ |
|
/* Now we do the background calculation without any gamma correction. */ |
|
if (that->alphaf <= 0) |
|
{ |
|
that->redf = data.redf; |
|
that->greenf = data.greenf; |
|
that->bluef = data.bluef; |
|
|
|
that->rede = data.rede; |
|
that->greene = data.greene; |
|
that->bluee = data.bluee; |
|
|
|
that->red_sBIT= data.red_sBIT; |
|
that->green_sBIT= data.green_sBIT; |
|
that->blue_sBIT= data.blue_sBIT; |
|
} |
|
|
|
else /* 0 < alpha < 1 */ |
|
{ |
|
double alf = 1 - that->alphaf; |
|
|
|
that->redf = that->redf * that->alphaf + data.redf * alf; |
|
that->rede = that->rede * that->alphaf + data.rede * alf + |
|
DBL_EPSILON; |
|
that->greenf = that->greenf * that->alphaf + data.greenf * alf; |
|
that->greene = that->greene * that->alphaf + data.greene * alf + |
|
DBL_EPSILON; |
|
that->bluef = that->bluef * that->alphaf + data.bluef * alf; |
|
that->bluee = that->bluee * that->alphaf + data.bluee * alf + |
|
DBL_EPSILON; |
|
} |
|
|
|
/* Remove the alpha type and set the alpha (not in that order.) */ |
|
that->alphaf = 1; |
|
that->alphae = 0; |
|
} |
|
|
|
if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_RGB; |
|
else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
that->colour_type = PNG_COLOR_TYPE_GRAY; |
|
/* PNG_COLOR_TYPE_PALETTE is not changed */ |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
#define image_transform_png_set_background_add image_transform_default_add |
|
|
|
#undef data |
|
IT(background); |
|
#undef PT |
|
#define PT ITSTRUCT(background) |
|
#endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
|
|
/* png_set_quantize(png_structp, png_colorp palette, int num_palette, |
|
* int maximum_colors, png_const_uint_16p histogram, int full_quantize) |
|
* |
|
* Very difficult to validate this! |
|
*/ |
|
/*NOTE: TBD NYI */ |
|
|
|
/* The data layout transforms are handled by swapping our own channel data, |
|
* necessarily these need to happen at the end of the transform list because the |
|
* semantic of the channels changes after these are executed. Some of these, |
|
* like set_shift and set_packing, can't be done at present because they change |
|
* the layout of the data at the sub-sample level so sample() won't get the |
|
* right answer. |
|
*/ |
|
/* png_set_invert_alpha */ |
|
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
|
/* Invert the alpha channel |
|
* |
|
* png_set_invert_alpha(png_structrp png_ptr) |
|
*/ |
|
static void |
|
image_transform_png_set_invert_alpha_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_invert_alpha(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_invert_alpha_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type & 4) |
|
that->alpha_inverted = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_invert_alpha_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* Only has an effect on pixels with alpha: */ |
|
return (colour_type & 4) != 0; |
|
} |
|
|
|
IT(invert_alpha); |
|
#undef PT |
|
#define PT ITSTRUCT(invert_alpha) |
|
|
|
#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED */ |
|
|
|
/* png_set_bgr */ |
|
#ifdef PNG_READ_BGR_SUPPORTED |
|
/* Swap R,G,B channels to order B,G,R. |
|
* |
|
* png_set_bgr(png_structrp png_ptr) |
|
* |
|
* This only has an effect on RGB and RGBA pixels. |
|
*/ |
|
static void |
|
image_transform_png_set_bgr_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_bgr(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_bgr_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type == PNG_COLOR_TYPE_RGB || |
|
that->colour_type == PNG_COLOR_TYPE_RGBA) |
|
that->swap_rgb = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_bgr_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return colour_type == PNG_COLOR_TYPE_RGB || |
|
colour_type == PNG_COLOR_TYPE_RGBA; |
|
} |
|
|
|
IT(bgr); |
|
#undef PT |
|
#define PT ITSTRUCT(bgr) |
|
|
|
#endif /* PNG_READ_BGR_SUPPORTED */ |
|
|
|
/* png_set_swap_alpha */ |
|
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
|
/* Put the alpha channel first. |
|
* |
|
* png_set_swap_alpha(png_structrp png_ptr) |
|
* |
|
* This only has an effect on GA and RGBA pixels. |
|
*/ |
|
static void |
|
image_transform_png_set_swap_alpha_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_swap_alpha(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_swap_alpha_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type == PNG_COLOR_TYPE_GA || |
|
that->colour_type == PNG_COLOR_TYPE_RGBA) |
|
that->alpha_first = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_swap_alpha_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return colour_type == PNG_COLOR_TYPE_GA || |
|
colour_type == PNG_COLOR_TYPE_RGBA; |
|
} |
|
|
|
IT(swap_alpha); |
|
#undef PT |
|
#define PT ITSTRUCT(swap_alpha) |
|
|
|
#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED */ |
|
|
|
/* png_set_swap */ |
|
#ifdef PNG_READ_SWAP_SUPPORTED |
|
/* Byte swap 16-bit components. |
|
* |
|
* png_set_swap(png_structrp png_ptr) |
|
*/ |
|
static void |
|
image_transform_png_set_swap_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_swap(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_swap_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth == 16) |
|
that->swap16 = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_swap_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth == 16; |
|
} |
|
|
|
IT(swap); |
|
#undef PT |
|
#define PT ITSTRUCT(swap) |
|
|
|
#endif /* PNG_READ_SWAP_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_FILLER_SUPPORTED |
|
/* Add a filler byte to 8-bit Gray or 24-bit RGB images. |
|
* |
|
* png_set_filler, (png_structp png_ptr, png_uint_32 filler, int flags)); |
|
* |
|
* Flags: |
|
* |
|
* PNG_FILLER_BEFORE |
|
* PNG_FILLER_AFTER |
|
*/ |
|
#define data ITDATA(filler) |
|
static struct |
|
{ |
|
png_uint_32 filler; |
|
int flags; |
|
} data; |
|
|
|
static void |
|
image_transform_png_set_filler_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
/* Need a random choice for 'before' and 'after' as well as for the |
|
* filler. The 'filler' value has all 32 bits set, but only bit_depth |
|
* will be used. At this point we don't know bit_depth. |
|
*/ |
|
data.filler = random_u32(); |
|
data.flags = random_choice(); |
|
|
|
png_set_filler(pp, data.filler, data.flags); |
|
|
|
/* The standard display handling stuff also needs to know that |
|
* there is a filler, so set that here. |
|
*/ |
|
that->this.filler = 1; |
|
|
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_filler_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth >= 8 && |
|
(that->colour_type == PNG_COLOR_TYPE_RGB || |
|
that->colour_type == PNG_COLOR_TYPE_GRAY)) |
|
{ |
|
unsigned int max = (1U << that->bit_depth)-1; |
|
that->alpha = data.filler & max; |
|
that->alphaf = ((double)that->alpha) / max; |
|
that->alphae = 0; |
|
|
|
/* The filler has been stored in the alpha channel, we must record |
|
* that this has been done for the checking later on, the color |
|
* type is faked to have an alpha channel, but libpng won't report |
|
* this; the app has to know the extra channel is there and this |
|
* was recording in standard_display::filler above. |
|
*/ |
|
that->colour_type |= 4; /* alpha added */ |
|
that->alpha_first = data.flags == PNG_FILLER_BEFORE; |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_filler_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || |
|
colour_type == PNG_COLOR_TYPE_GRAY); |
|
} |
|
|
|
#undef data |
|
IT(filler); |
|
#undef PT |
|
#define PT ITSTRUCT(filler) |
|
|
|
/* png_set_add_alpha, (png_structp png_ptr, png_uint_32 filler, int flags)); */ |
|
/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */ |
|
#define data ITDATA(add_alpha) |
|
static struct |
|
{ |
|
png_uint_32 filler; |
|
int flags; |
|
} data; |
|
|
|
static void |
|
image_transform_png_set_add_alpha_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
/* Need a random choice for 'before' and 'after' as well as for the |
|
* filler. The 'filler' value has all 32 bits set, but only bit_depth |
|
* will be used. At this point we don't know bit_depth. |
|
*/ |
|
data.filler = random_u32(); |
|
data.flags = random_choice(); |
|
|
|
png_set_add_alpha(pp, data.filler, data.flags); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_add_alpha_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth >= 8 && |
|
(that->colour_type == PNG_COLOR_TYPE_RGB || |
|
that->colour_type == PNG_COLOR_TYPE_GRAY)) |
|
{ |
|
unsigned int max = (1U << that->bit_depth)-1; |
|
that->alpha = data.filler & max; |
|
that->alphaf = ((double)that->alpha) / max; |
|
that->alphae = 0; |
|
|
|
that->colour_type |= 4; /* alpha added */ |
|
that->alpha_first = data.flags == PNG_FILLER_BEFORE; |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_add_alpha_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth >= 8 && (colour_type == PNG_COLOR_TYPE_RGB || |
|
colour_type == PNG_COLOR_TYPE_GRAY); |
|
} |
|
|
|
#undef data |
|
IT(add_alpha); |
|
#undef PT |
|
#define PT ITSTRUCT(add_alpha) |
|
|
|
#endif /* PNG_READ_FILLER_SUPPORTED */ |
|
|
|
/* png_set_packing */ |
|
#ifdef PNG_READ_PACK_SUPPORTED |
|
/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. |
|
* |
|
* png_set_packing(png_structrp png_ptr) |
|
* |
|
* This should only affect grayscale and palette images with less than 8 bits |
|
* per pixel. |
|
*/ |
|
static void |
|
image_transform_png_set_packing_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_packing(pp); |
|
that->unpacked = 1; |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_packing_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* The general expand case depends on what the colour type is, |
|
* low bit-depth pixel values are unpacked into bytes without |
|
* scaling, so sample_depth is not changed. |
|
*/ |
|
if (that->bit_depth < 8) /* grayscale or palette */ |
|
that->bit_depth = 8; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_packing_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* Nothing should happen unless the bit depth is less than 8: */ |
|
return bit_depth < 8; |
|
} |
|
|
|
IT(packing); |
|
#undef PT |
|
#define PT ITSTRUCT(packing) |
|
|
|
#endif /* PNG_READ_PACK_SUPPORTED */ |
|
|
|
/* png_set_packswap */ |
|
#ifdef PNG_READ_PACKSWAP_SUPPORTED |
|
/* Swap pixels packed into bytes; reverses the order on screen so that |
|
* the high order bits correspond to the rightmost pixels. |
|
* |
|
* png_set_packswap(png_structrp png_ptr) |
|
*/ |
|
static void |
|
image_transform_png_set_packswap_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_packswap(pp); |
|
that->this.littleendian = 1; |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_packswap_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->bit_depth < 8) |
|
that->littleendian = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_packswap_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(colour_type) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return bit_depth < 8; |
|
} |
|
|
|
IT(packswap); |
|
#undef PT |
|
#define PT ITSTRUCT(packswap) |
|
|
|
#endif /* PNG_READ_PACKSWAP_SUPPORTED */ |
|
|
|
|
|
/* png_set_invert_mono */ |
|
#ifdef PNG_READ_INVERT_MONO_SUPPORTED |
|
/* Invert the gray channel |
|
* |
|
* png_set_invert_mono(png_structrp png_ptr) |
|
*/ |
|
static void |
|
image_transform_png_set_invert_mono_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_invert_mono(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_invert_mono_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
if (that->colour_type & 4) |
|
that->mono_inverted = 1; |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_invert_mono_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
/* Only has an effect on pixels with no colour: */ |
|
return (colour_type & 2) == 0; |
|
} |
|
|
|
IT(invert_mono); |
|
#undef PT |
|
#define PT ITSTRUCT(invert_mono) |
|
|
|
#endif /* PNG_READ_INVERT_MONO_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_SHIFT_SUPPORTED |
|
/* png_set_shift(png_structp, png_const_color_8p true_bits) |
|
* |
|
* The output pixels will be shifted by the given true_bits |
|
* values. |
|
*/ |
|
#define data ITDATA(shift) |
|
static png_color_8 data; |
|
|
|
static void |
|
image_transform_png_set_shift_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
/* Get a random set of shifts. The shifts need to do something |
|
* to test the transform, so they are limited to the bit depth |
|
* of the input image. Notice that in the following the 'gray' |
|
* field is randomized independently. This acts as a check that |
|
* libpng does use the correct field. |
|
*/ |
|
unsigned int depth = that->this.bit_depth; |
|
|
|
data.red = (png_byte)/*SAFE*/(random_mod(depth)+1); |
|
data.green = (png_byte)/*SAFE*/(random_mod(depth)+1); |
|
data.blue = (png_byte)/*SAFE*/(random_mod(depth)+1); |
|
data.gray = (png_byte)/*SAFE*/(random_mod(depth)+1); |
|
data.alpha = (png_byte)/*SAFE*/(random_mod(depth)+1); |
|
|
|
png_set_shift(pp, &data); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_shift_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
/* Copy the correct values into the sBIT fields, libpng does not do |
|
* anything to palette data: |
|
*/ |
|
if (that->colour_type != PNG_COLOR_TYPE_PALETTE) |
|
{ |
|
that->sig_bits = 1; |
|
|
|
/* The sBIT fields are reset to the values previously sent to |
|
* png_set_shift according to the colour type. |
|
* does. |
|
*/ |
|
if (that->colour_type & 2) /* RGB channels */ |
|
{ |
|
that->red_sBIT = data.red; |
|
that->green_sBIT = data.green; |
|
that->blue_sBIT = data.blue; |
|
} |
|
|
|
else /* One grey channel */ |
|
that->red_sBIT = that->green_sBIT = that->blue_sBIT = data.gray; |
|
|
|
that->alpha_sBIT = data.alpha; |
|
} |
|
|
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_shift_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
UNUSED(bit_depth) |
|
|
|
this->next = *that; |
|
*that = this; |
|
|
|
return colour_type != PNG_COLOR_TYPE_PALETTE; |
|
} |
|
|
|
IT(shift); |
|
#undef PT |
|
#define PT ITSTRUCT(shift) |
|
|
|
#endif /* PNG_READ_SHIFT_SUPPORTED */ |
|
|
|
#ifdef THIS_IS_THE_PROFORMA |
|
static void |
|
image_transform_png_set_@_set(const image_transform *this, |
|
transform_display *that, png_structp pp, png_infop pi) |
|
{ |
|
png_set_@(pp); |
|
this->next->set(this->next, that, pp, pi); |
|
} |
|
|
|
static void |
|
image_transform_png_set_@_mod(const image_transform *this, |
|
image_pixel *that, png_const_structp pp, |
|
const transform_display *display) |
|
{ |
|
this->next->mod(this->next, that, pp, display); |
|
} |
|
|
|
static int |
|
image_transform_png_set_@_add(image_transform *this, |
|
const image_transform **that, png_byte colour_type, png_byte bit_depth) |
|
{ |
|
this->next = *that; |
|
*that = this; |
|
|
|
return 1; |
|
} |
|
|
|
IT(@); |
|
#endif |
|
|
|
|
|
/* This may just be 'end' if all the transforms are disabled! */ |
|
static image_transform *const image_transform_first = &PT; |
|
|
|
static void |
|
transform_enable(const char *name) |
|
{ |
|
/* Everything starts out enabled, so if we see an 'enable' disabled |
|
* everything else the first time round. |
|
*/ |
|
static int all_disabled = 0; |
|
int found_it = 0; |
|
image_transform *list = image_transform_first; |
|
|
|
while (list != &image_transform_end) |
|
{ |
|
if (strcmp(list->name, name) == 0) |
|
{ |
|
list->enable = 1; |
|
found_it = 1; |
|
} |
|
else if (!all_disabled) |
|
list->enable = 0; |
|
|
|
list = list->list; |
|
} |
|
|
|
all_disabled = 1; |
|
|
|
if (!found_it) |
|
{ |
|
fprintf(stderr, "pngvalid: --transform-enable=%s: unknown transform\n", |
|
name); |
|
exit(99); |
|
} |
|
} |
|
|
|
static void |
|
transform_disable(const char *name) |
|
{ |
|
image_transform *list = image_transform_first; |
|
|
|
while (list != &image_transform_end) |
|
{ |
|
if (strcmp(list->name, name) == 0) |
|
{ |
|
list->enable = 0; |
|
return; |
|
} |
|
|
|
list = list->list; |
|
} |
|
|
|
fprintf(stderr, "pngvalid: --transform-disable=%s: unknown transform\n", |
|
name); |
|
exit(99); |
|
} |
|
|
|
static void |
|
image_transform_reset_count(void) |
|
{ |
|
image_transform *next = image_transform_first; |
|
int count = 0; |
|
|
|
while (next != &image_transform_end) |
|
{ |
|
next->local_use = 0; |
|
next->next = 0; |
|
next = next->list; |
|
++count; |
|
} |
|
|
|
/* This can only happen if we every have more than 32 transforms (excluding |
|
* the end) in the list. |
|
*/ |
|
if (count > 32) abort(); |
|
} |
|
|
|
static int |
|
image_transform_test_counter(png_uint_32 counter, unsigned int max) |
|
{ |
|
/* Test the list to see if there is any point contining, given a current |
|
* counter and a 'max' value. |
|
*/ |
|
image_transform *next = image_transform_first; |
|
|
|
while (next != &image_transform_end) |
|
{ |
|
/* For max 0 or 1 continue until the counter overflows: */ |
|
counter >>= 1; |
|
|
|
/* Continue if any entry hasn't reacked the max. */ |
|
if (max > 1 && next->local_use < max) |
|
return 1; |
|
next = next->list; |
|
} |
|
|
|
return max <= 1 && counter == 0; |
|
} |
|
|
|
static png_uint_32 |
|
image_transform_add(const image_transform **this, unsigned int max, |
|
png_uint_32 counter, char *name, size_t sizeof_name, size_t *pos, |
|
png_byte colour_type, png_byte bit_depth) |
|
{ |
|
for (;;) /* until we manage to add something */ |
|
{ |
|
png_uint_32 mask; |
|
image_transform *list; |
|
|
|
/* Find the next counter value, if the counter is zero this is the start |
|
* of the list. This routine always returns the current counter (not the |
|
* next) so it returns 0 at the end and expects 0 at the beginning. |
|
*/ |
|
if (counter == 0) /* first time */ |
|
{ |
|
image_transform_reset_count(); |
|
if (max <= 1) |
|
counter = 1; |
|
else |
|
counter = random_32(); |
|
} |
|
else /* advance the counter */ |
|
{ |
|
switch (max) |
|
{ |
|
case 0: ++counter; break; |
|
case 1: counter <<= 1; break; |
|
default: counter = random_32(); break; |
|
} |
|
} |
|
|
|
/* Now add all these items, if possible */ |
|
*this = &image_transform_end; |
|
list = image_transform_first; |
|
mask = 1; |
|
|
|
/* Go through the whole list adding anything that the counter selects: */ |
|
while (list != &image_transform_end) |
|
{ |
|
if ((counter & mask) != 0 && list->enable && |
|
(max == 0 || list->local_use < max)) |
|
{ |
|
/* Candidate to add: */ |
|
if (list->add(list, this, colour_type, bit_depth) || max == 0) |
|
{ |
|
/* Added, so add to the name too. */ |
|
*pos = safecat(name, sizeof_name, *pos, " +"); |
|
*pos = safecat(name, sizeof_name, *pos, list->name); |
|
} |
|
|
|
else |
|
{ |
|
/* Not useful and max>0, so remove it from *this: */ |
|
*this = list->next; |
|
list->next = 0; |
|
|
|
/* And, since we know it isn't useful, stop it being added again |
|
* in this run: |
|
*/ |
|
list->local_use = max; |
|
} |
|
} |
|
|
|
mask <<= 1; |
|
list = list->list; |
|
} |
|
|
|
/* Now if anything was added we have something to do. */ |
|
if (*this != &image_transform_end) |
|
return counter; |
|
|
|
/* Nothing added, but was there anything in there to add? */ |
|
if (!image_transform_test_counter(counter, max)) |
|
return 0; |
|
} |
|
} |
|
|
|
static void |
|
perform_transform_test(png_modifier *pm) |
|
{ |
|
png_byte colour_type = 0; |
|
png_byte bit_depth = 0; |
|
unsigned int palette_number = 0; |
|
|
|
while (next_format(&colour_type, &bit_depth, &palette_number, pm->test_lbg, |
|
pm->test_tRNS)) |
|
{ |
|
png_uint_32 counter = 0; |
|
size_t base_pos; |
|
char name[64]; |
|
|
|
base_pos = safecat(name, sizeof name, 0, "transform:"); |
|
|
|
for (;;) |
|
{ |
|
size_t pos = base_pos; |
|
const image_transform *list = 0; |
|
|
|
/* 'max' is currently hardwired to '1'; this should be settable on the |
|
* command line. |
|
*/ |
|
counter = image_transform_add(&list, 1/*max*/, counter, |
|
name, sizeof name, &pos, colour_type, bit_depth); |
|
|
|
if (counter == 0) |
|
break; |
|
|
|
/* The command line can change this to checking interlaced images. */ |
|
do |
|
{ |
|
pm->repeat = 0; |
|
transform_test(pm, FILEID(colour_type, bit_depth, palette_number, |
|
pm->interlace_type, 0, 0, 0), list, name); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
while (pm->repeat); |
|
} |
|
} |
|
} |
|
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
|
|
/********************************* GAMMA TESTS ********************************/ |
|
#ifdef PNG_READ_GAMMA_SUPPORTED |
|
/* Reader callbacks and implementations, where they differ from the standard |
|
* ones. |
|
*/ |
|
typedef struct gamma_display |
|
{ |
|
standard_display this; |
|
|
|
/* Parameters */ |
|
png_modifier* pm; |
|
double file_gamma; |
|
double screen_gamma; |
|
double background_gamma; |
|
png_byte sbit; |
|
int threshold_test; |
|
int use_input_precision; |
|
int scale16; |
|
int expand16; |
|
int do_background; |
|
png_color_16 background_color; |
|
|
|
/* Local variables */ |
|
double maxerrout; |
|
double maxerrpc; |
|
double maxerrabs; |
|
} gamma_display; |
|
|
|
#define ALPHA_MODE_OFFSET 4 |
|
|
|
static void |
|
gamma_display_init(gamma_display *dp, png_modifier *pm, png_uint_32 id, |
|
double file_gamma, double screen_gamma, png_byte sbit, int threshold_test, |
|
int use_input_precision, int scale16, int expand16, |
|
int do_background, const png_color_16 *pointer_to_the_background_color, |
|
double background_gamma) |
|
{ |
|
/* Standard fields */ |
|
standard_display_init(&dp->this, &pm->this, id, do_read_interlace, |
|
pm->use_update_info); |
|
|
|
/* Parameter fields */ |
|
dp->pm = pm; |
|
dp->file_gamma = file_gamma; |
|
dp->screen_gamma = screen_gamma; |
|
dp->background_gamma = background_gamma; |
|
dp->sbit = sbit; |
|
dp->threshold_test = threshold_test; |
|
dp->use_input_precision = use_input_precision; |
|
dp->scale16 = scale16; |
|
dp->expand16 = expand16; |
|
dp->do_background = do_background; |
|
if (do_background && pointer_to_the_background_color != 0) |
|
dp->background_color = *pointer_to_the_background_color; |
|
else |
|
memset(&dp->background_color, 0, sizeof dp->background_color); |
|
|
|
/* Local variable fields */ |
|
dp->maxerrout = dp->maxerrpc = dp->maxerrabs = 0; |
|
} |
|
|
|
static void |
|
gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi) |
|
{ |
|
/* Reuse the standard stuff as appropriate. */ |
|
standard_info_part1(&dp->this, pp, pi); |
|
|
|
/* If requested strip 16 to 8 bits - this is handled automagically below |
|
* because the output bit depth is read from the library. Note that there |
|
* are interactions with sBIT but, internally, libpng makes sbit at most |
|
* PNG_MAX_GAMMA_8 prior to 1.7 when doing the following. |
|
*/ |
|
if (dp->scale16) |
|
# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
|
png_set_scale_16(pp); |
|
# else |
|
/* The following works both in 1.5.4 and earlier versions: */ |
|
# ifdef PNG_READ_16_TO_8_SUPPORTED |
|
png_set_strip_16(pp); |
|
# else |
|
png_error(pp, "scale16 (16 to 8 bit conversion) not supported"); |
|
# endif |
|
# endif |
|
|
|
if (dp->expand16) |
|
# ifdef PNG_READ_EXPAND_16_SUPPORTED |
|
png_set_expand_16(pp); |
|
# else |
|
png_error(pp, "expand16 (8 to 16 bit conversion) not supported"); |
|
# endif |
|
|
|
if (dp->do_background >= ALPHA_MODE_OFFSET) |
|
{ |
|
# ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
{ |
|
/* This tests the alpha mode handling, if supported. */ |
|
int mode = dp->do_background - ALPHA_MODE_OFFSET; |
|
|
|
/* The gamma value is the output gamma, and is in the standard, |
|
* non-inverted, representation. It provides a default for the PNG file |
|
* gamma, but since the file has a gAMA chunk this does not matter. |
|
*/ |
|
const double sg = dp->screen_gamma; |
|
# ifndef PNG_FLOATING_POINT_SUPPORTED |
|
png_fixed_point g = fix(sg); |
|
# endif |
|
|
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_alpha_mode(pp, mode, sg); |
|
# else |
|
png_set_alpha_mode_fixed(pp, mode, g); |
|
# endif |
|
|
|
/* However, for the standard Porter-Duff algorithm the output defaults |
|
* to be linear, so if the test requires non-linear output it must be |
|
* corrected here. |
|
*/ |
|
if (mode == PNG_ALPHA_STANDARD && sg != 1) |
|
{ |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_gamma(pp, sg, dp->file_gamma); |
|
# else |
|
png_fixed_point f = fix(dp->file_gamma); |
|
png_set_gamma_fixed(pp, g, f); |
|
# endif |
|
} |
|
} |
|
# else |
|
png_error(pp, "alpha mode handling not supported"); |
|
# endif |
|
} |
|
|
|
else |
|
{ |
|
/* Set up gamma processing. */ |
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_gamma(pp, dp->screen_gamma, dp->file_gamma); |
|
# else |
|
{ |
|
png_fixed_point s = fix(dp->screen_gamma); |
|
png_fixed_point f = fix(dp->file_gamma); |
|
png_set_gamma_fixed(pp, s, f); |
|
} |
|
# endif |
|
|
|
if (dp->do_background) |
|
{ |
|
# ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
/* NOTE: this assumes the caller provided the correct background gamma! |
|
*/ |
|
const double bg = dp->background_gamma; |
|
# ifndef PNG_FLOATING_POINT_SUPPORTED |
|
png_fixed_point g = fix(bg); |
|
# endif |
|
|
|
# ifdef PNG_FLOATING_POINT_SUPPORTED |
|
png_set_background(pp, &dp->background_color, dp->do_background, |
|
0/*need_expand*/, bg); |
|
# else |
|
png_set_background_fixed(pp, &dp->background_color, |
|
dp->do_background, 0/*need_expand*/, g); |
|
# endif |
|
# else |
|
png_error(pp, "png_set_background not supported"); |
|
# endif |
|
} |
|
} |
|
|
|
{ |
|
int i = dp->this.use_update_info; |
|
/* Always do one call, even if use_update_info is 0. */ |
|
do |
|
png_read_update_info(pp, pi); |
|
while (--i > 0); |
|
} |
|
|
|
/* Now we may get a different cbRow: */ |
|
standard_info_part2(&dp->this, pp, pi, 1 /*images*/); |
|
} |
|
|
|
static void PNGCBAPI |
|
gamma_info(png_structp pp, png_infop pi) |
|
{ |
|
gamma_info_imp(voidcast(gamma_display*, png_get_progressive_ptr(pp)), pp, |
|
pi); |
|
} |
|
|
|
/* Validate a single component value - the routine gets the input and output |
|
* sample values as unscaled PNG component values along with a cache of all the |
|
* information required to validate the values. |
|
*/ |
|
typedef struct validate_info |
|
{ |
|
png_const_structp pp; |
|
gamma_display *dp; |
|
png_byte sbit; |
|
int use_input_precision; |
|
int do_background; |
|
int scale16; |
|
unsigned int sbit_max; |
|
unsigned int isbit_shift; |
|
unsigned int outmax; |
|
|
|
double gamma_correction; /* Overall correction required. */ |
|
double file_inverse; /* Inverse of file gamma. */ |
|
double screen_gamma; |
|
double screen_inverse; /* Inverse of screen gamma. */ |
|
|
|
double background_red; /* Linear background value, red or gray. */ |
|
double background_green; |
|
double background_blue; |
|
|
|
double maxabs; |
|
double maxpc; |
|
double maxcalc; |
|
double maxout; |
|
double maxout_total; /* Total including quantization error */ |
|
double outlog; |
|
int outquant; |
|
} |
|
validate_info; |
|
|
|
static void |
|
init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp, |
|
int in_depth, int out_depth) |
|
{ |
|
unsigned int outmax = (1U<<out_depth)-1; |
|
|
|
vi->pp = pp; |
|
vi->dp = dp; |
|
|
|
if (dp->sbit > 0 && dp->sbit < in_depth) |
|
{ |
|
vi->sbit = dp->sbit; |
|
vi->isbit_shift = in_depth - dp->sbit; |
|
} |
|
|
|
else |
|
{ |
|
vi->sbit = (png_byte)in_depth; |
|
vi->isbit_shift = 0; |
|
} |
|
|
|
vi->sbit_max = (1U << vi->sbit)-1; |
|
|
|
/* This mimics the libpng threshold test, '0' is used to prevent gamma |
|
* correction in the validation test. |
|
*/ |
|
vi->screen_gamma = dp->screen_gamma; |
|
if (fabs(vi->screen_gamma-1) < PNG_GAMMA_THRESHOLD) |
|
vi->screen_gamma = vi->screen_inverse = 0; |
|
else |
|
vi->screen_inverse = 1/vi->screen_gamma; |
|
|
|
vi->use_input_precision = dp->use_input_precision; |
|
vi->outmax = outmax; |
|
vi->maxabs = abserr(dp->pm, in_depth, out_depth); |
|
vi->maxpc = pcerr(dp->pm, in_depth, out_depth); |
|
vi->maxcalc = calcerr(dp->pm, in_depth, out_depth); |
|
vi->maxout = outerr(dp->pm, in_depth, out_depth); |
|
vi->outquant = output_quantization_factor(dp->pm, in_depth, out_depth); |
|
vi->maxout_total = vi->maxout + vi->outquant * .5; |
|
vi->outlog = outlog(dp->pm, in_depth, out_depth); |
|
|
|
if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 || |
|
(dp->this.colour_type == 3 && dp->this.is_transparent) || |
|
((dp->this.colour_type == 0 || dp->this.colour_type == 2) && |
|
dp->this.has_tRNS)) |
|
{ |
|
vi->do_background = dp->do_background; |
|
|
|
if (vi->do_background != 0) |
|
{ |
|
const double bg_inverse = 1/dp->background_gamma; |
|
double r, g, b; |
|
|
|
/* Caller must at least put the gray value into the red channel */ |
|
r = dp->background_color.red; r /= outmax; |
|
g = dp->background_color.green; g /= outmax; |
|
b = dp->background_color.blue; b /= outmax; |
|
|
|
# if 0 |
|
/* libpng doesn't do this optimization, if we do pngvalid will fail. |
|
*/ |
|
if (fabs(bg_inverse-1) >= PNG_GAMMA_THRESHOLD) |
|
# endif |
|
{ |
|
r = pow(r, bg_inverse); |
|
g = pow(g, bg_inverse); |
|
b = pow(b, bg_inverse); |
|
} |
|
|
|
vi->background_red = r; |
|
vi->background_green = g; |
|
vi->background_blue = b; |
|
} |
|
} |
|
else /* Do not expect any background processing */ |
|
vi->do_background = 0; |
|
|
|
if (vi->do_background == 0) |
|
vi->background_red = vi->background_green = vi->background_blue = 0; |
|
|
|
vi->gamma_correction = 1/(dp->file_gamma*dp->screen_gamma); |
|
if (fabs(vi->gamma_correction-1) < PNG_GAMMA_THRESHOLD) |
|
vi->gamma_correction = 0; |
|
|
|
vi->file_inverse = 1/dp->file_gamma; |
|
if (fabs(vi->file_inverse-1) < PNG_GAMMA_THRESHOLD) |
|
vi->file_inverse = 0; |
|
|
|
vi->scale16 = dp->scale16; |
|
} |
|
|
|
/* This function handles composition of a single non-alpha component. The |
|
* argument is the input sample value, in the range 0..1, and the alpha value. |
|
* The result is the composed, linear, input sample. If alpha is less than zero |
|
* this is the alpha component and the function should not be called! |
|
*/ |
|
static double |
|
gamma_component_compose(int do_background, double input_sample, double alpha, |
|
double background, int *compose) |
|
{ |
|
switch (do_background) |
|
{ |
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
case PNG_BACKGROUND_GAMMA_SCREEN: |
|
case PNG_BACKGROUND_GAMMA_FILE: |
|
case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
/* Standard PNG background processing. */ |
|
if (alpha < 1) |
|
{ |
|
if (alpha > 0) |
|
{ |
|
input_sample = input_sample * alpha + background * (1-alpha); |
|
if (compose != NULL) |
|
*compose = 1; |
|
} |
|
|
|
else |
|
input_sample = background; |
|
} |
|
break; |
|
#endif |
|
|
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: |
|
/* The components are premultiplied in either case and the output is |
|
* gamma encoded (to get standard Porter-Duff we expect the output |
|
* gamma to be set to 1.0!) |
|
*/ |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: |
|
/* The optimization is that the partial-alpha entries are linear |
|
* while the opaque pixels are gamma encoded, but this only affects the |
|
* output encoding. |
|
*/ |
|
if (alpha < 1) |
|
{ |
|
if (alpha > 0) |
|
{ |
|
input_sample *= alpha; |
|
if (compose != NULL) |
|
*compose = 1; |
|
} |
|
|
|
else |
|
input_sample = 0; |
|
} |
|
break; |
|
#endif |
|
|
|
default: |
|
/* Standard cases where no compositing is done (so the component |
|
* value is already correct.) |
|
*/ |
|
UNUSED(alpha) |
|
UNUSED(background) |
|
UNUSED(compose) |
|
break; |
|
} |
|
|
|
return input_sample; |
|
} |
|
|
|
/* This API returns the encoded *input* component, in the range 0..1 */ |
|
static double |
|
gamma_component_validate(const char *name, const validate_info *vi, |
|
unsigned int id, unsigned int od, |
|
const double alpha /* <0 for the alpha channel itself */, |
|
const double background /* component background value */) |
|
{ |
|
unsigned int isbit = id >> vi->isbit_shift; |
|
unsigned int sbit_max = vi->sbit_max; |
|
unsigned int outmax = vi->outmax; |
|
int do_background = vi->do_background; |
|
|
|
double i; |
|
|
|
/* First check on the 'perfect' result obtained from the digitized input |
|
* value, id, and compare this against the actual digitized result, 'od'. |
|
* 'i' is the input result in the range 0..1: |
|
*/ |
|
i = isbit; i /= sbit_max; |
|
|
|
/* Check for the fast route: if we don't do any background composition or if |
|
* this is the alpha channel ('alpha' < 0) or if the pixel is opaque then |
|
* just use the gamma_correction field to correct to the final output gamma. |
|
*/ |
|
if (alpha == 1 /* opaque pixel component */ || !do_background |
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
|| do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG |
|
#endif |
|
|| (alpha < 0 /* alpha channel */ |
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
&& do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN |
|
#endif |
|
)) |
|
{ |
|
/* Then get the gamma corrected version of 'i' and compare to 'od', any |
|
* error less than .5 is insignificant - just quantization of the output |
|
* value to the nearest digital value (nevertheless the error is still |
|
* recorded - it's interesting ;-) |
|
*/ |
|
double encoded_sample = i; |
|
double encoded_error; |
|
|
|
/* alpha less than 0 indicates the alpha channel, which is always linear |
|
*/ |
|
if (alpha >= 0 && vi->gamma_correction > 0) |
|
encoded_sample = pow(encoded_sample, vi->gamma_correction); |
|
encoded_sample *= outmax; |
|
|
|
encoded_error = fabs(od-encoded_sample); |
|
|
|
if (encoded_error > vi->dp->maxerrout) |
|
vi->dp->maxerrout = encoded_error; |
|
|
|
if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) |
|
return i; |
|
} |
|
|
|
/* The slow route - attempt to do linear calculations. */ |
|
/* There may be an error, or background processing is required, so calculate |
|
* the actual sample values - unencoded light intensity values. Note that in |
|
* practice these are not completely unencoded because they include a |
|
* 'viewing correction' to decrease or (normally) increase the perceptual |
|
* contrast of the image. There's nothing we can do about this - we don't |
|
* know what it is - so assume the unencoded value is perceptually linear. |
|
*/ |
|
{ |
|
double input_sample = i; /* In range 0..1 */ |
|
double output, error, encoded_sample, encoded_error; |
|
double es_lo, es_hi; |
|
int compose = 0; /* Set to one if composition done */ |
|
int output_is_encoded; /* Set if encoded to screen gamma */ |
|
int log_max_error = 1; /* Check maximum error values */ |
|
png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ |
|
|
|
/* Convert to linear light (with the above caveat.) The alpha channel is |
|
* already linear. |
|
*/ |
|
if (alpha >= 0) |
|
{ |
|
int tcompose; |
|
|
|
if (vi->file_inverse > 0) |
|
input_sample = pow(input_sample, vi->file_inverse); |
|
|
|
/* Handle the compose processing: */ |
|
tcompose = 0; |
|
input_sample = gamma_component_compose(do_background, input_sample, |
|
alpha, background, &tcompose); |
|
|
|
if (tcompose) |
|
compose = 1; |
|
} |
|
|
|
/* And similarly for the output value, but we need to check the background |
|
* handling to linearize it correctly. |
|
*/ |
|
output = od; |
|
output /= outmax; |
|
|
|
output_is_encoded = vi->screen_gamma > 0; |
|
|
|
if (alpha < 0) /* The alpha channel */ |
|
{ |
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) |
|
#endif |
|
{ |
|
/* In all other cases the output alpha channel is linear already, |
|
* don't log errors here, they are much larger in linear data. |
|
*/ |
|
output_is_encoded = 0; |
|
log_max_error = 0; |
|
} |
|
} |
|
|
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
else /* A component */ |
|
{ |
|
if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && |
|
alpha < 1) /* the optimized case - linear output */ |
|
{ |
|
if (alpha > 0) log_max_error = 0; |
|
output_is_encoded = 0; |
|
} |
|
} |
|
#endif |
|
|
|
if (output_is_encoded) |
|
output = pow(output, vi->screen_gamma); |
|
|
|
/* Calculate (or recalculate) the encoded_sample value and repeat the |
|
* check above (unnecessary if we took the fast route, but harmless.) |
|
*/ |
|
encoded_sample = input_sample; |
|
if (output_is_encoded) |
|
encoded_sample = pow(encoded_sample, vi->screen_inverse); |
|
encoded_sample *= outmax; |
|
|
|
encoded_error = fabs(od-encoded_sample); |
|
|
|
/* Don't log errors in the alpha channel, or the 'optimized' case, |
|
* neither are significant to the overall perception. |
|
*/ |
|
if (log_max_error && encoded_error > vi->dp->maxerrout) |
|
vi->dp->maxerrout = encoded_error; |
|
|
|
if (encoded_error < vi->maxout_total) |
|
{ |
|
if (encoded_error < vi->outlog) |
|
return i; |
|
|
|
/* Test passed but error is bigger than the log limit, record why the |
|
* test passed: |
|
*/ |
|
pass = "less than maxout:\n"; |
|
} |
|
|
|
/* i: the original input value in the range 0..1 |
|
* |
|
* pngvalid calculations: |
|
* input_sample: linear result; i linearized and composed, range 0..1 |
|
* encoded_sample: encoded result; input_sample scaled to output bit depth |
|
* |
|
* libpng calculations: |
|
* output: linear result; od scaled to 0..1 and linearized |
|
* od: encoded result from libpng |
|
*/ |
|
|
|
/* Now we have the numbers for real errors, both absolute values as as a |
|
* percentage of the correct value (output): |
|
*/ |
|
error = fabs(input_sample-output); |
|
|
|
if (log_max_error && error > vi->dp->maxerrabs) |
|
vi->dp->maxerrabs = error; |
|
|
|
/* The following is an attempt to ignore the tendency of quantization to |
|
* dominate the percentage errors for lower result values: |
|
*/ |
|
if (log_max_error && input_sample > .5) |
|
{ |
|
double percentage_error = error/input_sample; |
|
if (percentage_error > vi->dp->maxerrpc) |
|
vi->dp->maxerrpc = percentage_error; |
|
} |
|
|
|
/* Now calculate the digitization limits for 'encoded_sample' using the |
|
* 'max' values. Note that maxout is in the encoded space but maxpc and |
|
* maxabs are in linear light space. |
|
* |
|
* First find the maximum error in linear light space, range 0..1: |
|
*/ |
|
{ |
|
double tmp = input_sample * vi->maxpc; |
|
if (tmp < vi->maxabs) tmp = vi->maxabs; |
|
/* If 'compose' is true the composition was done in linear space using |
|
* integer arithmetic. This introduces an extra error of +/- 0.5 (at |
|
* least) in the integer space used. 'maxcalc' records this, taking |
|
* into account the possibility that even for 16 bit output 8 bit space |
|
* may have been used. |
|
*/ |
|
if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; |
|
|
|
/* The 'maxout' value refers to the encoded result, to compare with |
|
* this encode input_sample adjusted by the maximum error (tmp) above. |
|
*/ |
|
es_lo = encoded_sample - vi->maxout; |
|
|
|
if (es_lo > 0 && input_sample-tmp > 0) |
|
{ |
|
double low_value = input_sample-tmp; |
|
if (output_is_encoded) |
|
low_value = pow(low_value, vi->screen_inverse); |
|
low_value *= outmax; |
|
if (low_value < es_lo) es_lo = low_value; |
|
|
|
/* Quantize this appropriately: */ |
|
es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; |
|
} |
|
|
|
else |
|
es_lo = 0; |
|
|
|
es_hi = encoded_sample + vi->maxout; |
|
|
|
if (es_hi < outmax && input_sample+tmp < 1) |
|
{ |
|
double high_value = input_sample+tmp; |
|
if (output_is_encoded) |
|
high_value = pow(high_value, vi->screen_inverse); |
|
high_value *= outmax; |
|
if (high_value > es_hi) es_hi = high_value; |
|
|
|
es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; |
|
} |
|
|
|
else |
|
es_hi = outmax; |
|
} |
|
|
|
/* The primary test is that the final encoded value returned by the |
|
* library should be between the two limits (inclusive) that were |
|
* calculated above. |
|
*/ |
|
if (od >= es_lo && od <= es_hi) |
|
{ |
|
/* The value passes, but we may need to log the information anyway. */ |
|
if (encoded_error < vi->outlog) |
|
return i; |
|
|
|
if (pass == 0) |
|
pass = "within digitization limits:\n"; |
|
} |
|
|
|
{ |
|
/* There has been an error in processing, or we need to log this |
|
* value. |
|
*/ |
|
double is_lo, is_hi; |
|
|
|
/* pass is set at this point if either of the tests above would have |
|
* passed. Don't do these additional tests here - just log the |
|
* original [es_lo..es_hi] values. |
|
*/ |
|
if (pass == 0 && vi->use_input_precision && vi->dp->sbit) |
|
{ |
|
/* Ok, something is wrong - this actually happens in current libpng |
|
* 16-to-8 processing. Assume that the input value (id, adjusted |
|
* for sbit) can be anywhere between value-.5 and value+.5 - quite a |
|
* large range if sbit is low. |
|
* |
|
* NOTE: at present because the libpng gamma table stuff has been |
|
* changed to use a rounding algorithm to correct errors in 8-bit |
|
* calculations the precise sbit calculation (a shift) has been |
|
* lost. This can result in up to a +/-1 error in the presence of |
|
* an sbit less than the bit depth. |
|
*/ |
|
# if PNG_LIBPNG_VER < 10700 |
|
# define SBIT_ERROR .5 |
|
# else |
|
# define SBIT_ERROR 1. |
|
# endif |
|
double tmp = (isbit - SBIT_ERROR)/sbit_max; |
|
|
|
if (tmp <= 0) |
|
tmp = 0; |
|
|
|
else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) |
|
tmp = pow(tmp, vi->file_inverse); |
|
|
|
tmp = gamma_component_compose(do_background, tmp, alpha, background, |
|
NULL); |
|
|
|
if (output_is_encoded && tmp > 0 && tmp < 1) |
|
tmp = pow(tmp, vi->screen_inverse); |
|
|
|
is_lo = ceil(outmax * tmp - vi->maxout_total); |
|
|
|
if (is_lo < 0) |
|
is_lo = 0; |
|
|
|
tmp = (isbit + SBIT_ERROR)/sbit_max; |
|
|
|
if (tmp >= 1) |
|
tmp = 1; |
|
|
|
else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) |
|
tmp = pow(tmp, vi->file_inverse); |
|
|
|
tmp = gamma_component_compose(do_background, tmp, alpha, background, |
|
NULL); |
|
|
|
if (output_is_encoded && tmp > 0 && tmp < 1) |
|
tmp = pow(tmp, vi->screen_inverse); |
|
|
|
is_hi = floor(outmax * tmp + vi->maxout_total); |
|
|
|
if (is_hi > outmax) |
|
is_hi = outmax; |
|
|
|
if (!(od < is_lo || od > is_hi)) |
|
{ |
|
if (encoded_error < vi->outlog) |
|
return i; |
|
|
|
pass = "within input precision limits:\n"; |
|
} |
|
|
|
/* One last chance. If this is an alpha channel and the 16to8 |
|
* option has been used and 'inaccurate' scaling is used then the |
|
* bit reduction is obtained by simply using the top 8 bits of the |
|
* value. |
|
* |
|
* This is only done for older libpng versions when the 'inaccurate' |
|
* (chop) method of scaling was used. |
|
*/ |
|
# ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED |
|
# if PNG_LIBPNG_VER < 10504 |
|
/* This may be required for other components in the future, |
|
* but at present the presence of gamma correction effectively |
|
* prevents the errors in the component scaling (I don't quite |
|
* understand why, but since it's better this way I care not |
|
* to ask, JB 20110419.) |
|
*/ |
|
if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && |
|
vi->sbit + vi->isbit_shift == 16) |
|
{ |
|
tmp = ((id >> 8) - .5)/255; |
|
|
|
if (tmp > 0) |
|
{ |
|
is_lo = ceil(outmax * tmp - vi->maxout_total); |
|
if (is_lo < 0) is_lo = 0; |
|
} |
|
|
|
else |
|
is_lo = 0; |
|
|
|
tmp = ((id >> 8) + .5)/255; |
|
|
|
if (tmp < 1) |
|
{ |
|
is_hi = floor(outmax * tmp + vi->maxout_total); |
|
if (is_hi > outmax) is_hi = outmax; |
|
} |
|
|
|
else |
|
is_hi = outmax; |
|
|
|
if (!(od < is_lo || od > is_hi)) |
|
{ |
|
if (encoded_error < vi->outlog) |
|
return i; |
|
|
|
pass = "within 8 bit limits:\n"; |
|
} |
|
} |
|
# endif |
|
# endif |
|
} |
|
else /* !use_input_precision */ |
|
is_lo = es_lo, is_hi = es_hi; |
|
|
|
/* Attempt to output a meaningful error/warning message: the message |
|
* output depends on the background/composite operation being performed |
|
* because this changes what parameters were actually used above. |
|
*/ |
|
{ |
|
size_t pos = 0; |
|
/* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal |
|
* places. Just use outmax to work out which. |
|
*/ |
|
int precision = (outmax >= 1000 ? 6 : 3); |
|
int use_input=1, use_background=0, do_compose=0; |
|
char msg[256]; |
|
|
|
if (pass != 0) |
|
pos = safecat(msg, sizeof msg, pos, "\n\t"); |
|
|
|
/* Set up the various flags, the output_is_encoded flag above |
|
* is also used below. do_compose is just a double check. |
|
*/ |
|
switch (do_background) |
|
{ |
|
# ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
case PNG_BACKGROUND_GAMMA_SCREEN: |
|
case PNG_BACKGROUND_GAMMA_FILE: |
|
case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
use_background = (alpha >= 0 && alpha < 1); |
|
# endif |
|
# ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
/* FALLTHROUGH */ |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: |
|
# endif /* ALPHA_MODE_SUPPORTED */ |
|
do_compose = (alpha > 0 && alpha < 1); |
|
use_input = (alpha != 0); |
|
break; |
|
|
|
default: |
|
break; |
|
} |
|
|
|
/* Check the 'compose' flag */ |
|
if (compose != do_compose) |
|
png_error(vi->pp, "internal error (compose)"); |
|
|
|
/* 'name' is the component name */ |
|
pos = safecat(msg, sizeof msg, pos, name); |
|
pos = safecat(msg, sizeof msg, pos, "("); |
|
pos = safecatn(msg, sizeof msg, pos, id); |
|
if (use_input || pass != 0/*logging*/) |
|
{ |
|
if (isbit != id) |
|
{ |
|
/* sBIT has reduced the precision of the input: */ |
|
pos = safecat(msg, sizeof msg, pos, ", sbit("); |
|
pos = safecatn(msg, sizeof msg, pos, vi->sbit); |
|
pos = safecat(msg, sizeof msg, pos, "): "); |
|
pos = safecatn(msg, sizeof msg, pos, isbit); |
|
} |
|
pos = safecat(msg, sizeof msg, pos, "/"); |
|
/* The output is either "id/max" or "id sbit(sbit): isbit/max" */ |
|
pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); |
|
} |
|
pos = safecat(msg, sizeof msg, pos, ")"); |
|
|
|
/* A component may have been multiplied (in linear space) by the |
|
* alpha value, 'compose' says whether this is relevant. |
|
*/ |
|
if (compose || pass != 0) |
|
{ |
|
/* If any form of composition is being done report our |
|
* calculated linear value here (the code above doesn't record |
|
* the input value before composition is performed, so what |
|
* gets reported is the value after composition.) |
|
*/ |
|
if (use_input || pass != 0) |
|
{ |
|
if (vi->file_inverse > 0) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, "^"); |
|
pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); |
|
} |
|
|
|
else |
|
pos = safecat(msg, sizeof msg, pos, "[linear]"); |
|
|
|
pos = safecat(msg, sizeof msg, pos, "*(alpha)"); |
|
pos = safecatd(msg, sizeof msg, pos, alpha, precision); |
|
} |
|
|
|
/* Now record the *linear* background value if it was used |
|
* (this function is not passed the original, non-linear, |
|
* value but it is contained in the test name.) |
|
*/ |
|
if (use_background) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); |
|
pos = safecat(msg, sizeof msg, pos, "(background)"); |
|
pos = safecatd(msg, sizeof msg, pos, background, precision); |
|
pos = safecat(msg, sizeof msg, pos, "*"); |
|
pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); |
|
} |
|
} |
|
|
|
/* Report the calculated value (input_sample) and the linearized |
|
* libpng value (output) unless this is just a component gamma |
|
* correction. |
|
*/ |
|
if (compose || alpha < 0 || pass != 0) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, |
|
pass != 0 ? " =\n\t" : " = "); |
|
pos = safecatd(msg, sizeof msg, pos, input_sample, precision); |
|
pos = safecat(msg, sizeof msg, pos, " (libpng: "); |
|
pos = safecatd(msg, sizeof msg, pos, output, precision); |
|
pos = safecat(msg, sizeof msg, pos, ")"); |
|
|
|
/* Finally report the output gamma encoding, if any. */ |
|
if (output_is_encoded) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, " ^"); |
|
pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); |
|
pos = safecat(msg, sizeof msg, pos, "(to screen) ="); |
|
} |
|
|
|
else |
|
pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); |
|
} |
|
|
|
if ((!compose && alpha >= 0) || pass != 0) |
|
{ |
|
if (pass != 0) /* logging */ |
|
pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); |
|
|
|
/* This is the non-composition case, the internal linear |
|
* values are irrelevant (though the log below will reveal |
|
* them.) Output a much shorter warning/error message and report |
|
* the overall gamma correction. |
|
*/ |
|
if (vi->gamma_correction > 0) |
|
{ |
|
pos = safecat(msg, sizeof msg, pos, " ^"); |
|
pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); |
|
pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); |
|
} |
|
|
|
else |
|
pos = safecat(msg, sizeof msg, pos, |
|
" [no gamma correction] ="); |
|
|
|
if (pass != 0) |
|
pos = safecat(msg, sizeof msg, pos, "]"); |
|
} |
|
|
|
/* This is our calculated encoded_sample which should (but does |
|
* not) match od: |
|
*/ |
|
pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); |
|
pos = safecatd(msg, sizeof msg, pos, is_lo, 1); |
|
pos = safecat(msg, sizeof msg, pos, " < "); |
|
pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); |
|
pos = safecat(msg, sizeof msg, pos, " (libpng: "); |
|
pos = safecatn(msg, sizeof msg, pos, od); |
|
pos = safecat(msg, sizeof msg, pos, ")"); |
|
pos = safecat(msg, sizeof msg, pos, "/"); |
|
pos = safecatn(msg, sizeof msg, pos, outmax); |
|
pos = safecat(msg, sizeof msg, pos, " < "); |
|
pos = safecatd(msg, sizeof msg, pos, is_hi, 1); |
|
|
|
if (pass == 0) /* The error condition */ |
|
{ |
|
# ifdef PNG_WARNINGS_SUPPORTED |
|
png_warning(vi->pp, msg); |
|
# else |
|
store_warning(vi->pp, msg); |
|
# endif |
|
} |
|
|
|
else /* logging this value */ |
|
store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); |
|
} |
|
} |
|
} |
|
|
|
return i; |
|
} |
|
|
|
static void |
|
gamma_image_validate(gamma_display *dp, png_const_structp pp, |
|
png_infop pi) |
|
{ |
|
/* Get some constants derived from the input and output file formats: */ |
|
const png_store* const ps = dp->this.ps; |
|
png_byte in_ct = dp->this.colour_type; |
|
png_byte in_bd = dp->this.bit_depth; |
|
png_uint_32 w = dp->this.w; |
|
png_uint_32 h = dp->this.h; |
|
const size_t cbRow = dp->this.cbRow; |
|
png_byte out_ct = png_get_color_type(pp, pi); |
|
png_byte out_bd = png_get_bit_depth(pp, pi); |
|
|
|
/* There are three sources of error, firstly the quantization in the |
|
* file encoding, determined by sbit and/or the file depth, secondly |
|
* the output (screen) gamma and thirdly the output file encoding. |
|
* |
|
* Since this API receives the screen and file gamma in double |
|
* precision it is possible to calculate an exact answer given an input |
|
* pixel value. Therefore we assume that the *input* value is exact - |
|
* sample/maxsample - calculate the corresponding gamma corrected |
|
* output to the limits of double precision arithmetic and compare with |
|
* what libpng returns. |
|
* |
|
* Since the library must quantize the output to 8 or 16 bits there is |
|
* a fundamental limit on the accuracy of the output of +/-.5 - this |
|
* quantization limit is included in addition to the other limits |
|
* specified by the parameters to the API. (Effectively, add .5 |
|
* everywhere.) |
|
* |
|
* The behavior of the 'sbit' parameter is defined by section 12.5 |
|
* (sample depth scaling) of the PNG spec. That section forces the |
|
* decoder to assume that the PNG values have been scaled if sBIT is |
|
* present: |
|
* |
|
* png-sample = floor( input-sample * (max-out/max-in) + .5); |
|
* |
|
* This means that only a subset of the possible PNG values should |
|
* appear in the input. However, the spec allows the encoder to use a |
|
* variety of approximations to the above and doesn't require any |
|
* restriction of the values produced. |
|
* |
|
* Nevertheless the spec requires that the upper 'sBIT' bits of the |
|
* value stored in a PNG file be the original sample bits. |
|
* Consequently the code below simply scales the top sbit bits by |
|
* (1<<sbit)-1 to obtain an original sample value. |
|
* |
|
* Because there is limited precision in the input it is arguable that |
|
* an acceptable result is any valid result from input-.5 to input+.5. |
|
* The basic tests below do not do this, however if 'use_input_precision' |
|
* is set a subsequent test is performed above. |
|
*/ |
|
unsigned int samples_per_pixel = (out_ct & 2U) ? 3U : 1U; |
|
int processing; |
|
png_uint_32 y; |
|
const store_palette_entry *in_palette = dp->this.palette; |
|
int in_is_transparent = dp->this.is_transparent; |
|
int process_tRNS; |
|
int out_npalette = -1; |
|
int out_is_transparent = 0; /* Just refers to the palette case */ |
|
store_palette out_palette; |
|
validate_info vi; |
|
|
|
/* Check for row overwrite errors */ |
|
store_image_check(dp->this.ps, pp, 0); |
|
|
|
/* Supply the input and output sample depths here - 8 for an indexed image, |
|
* otherwise the bit depth. |
|
*/ |
|
init_validate_info(&vi, dp, pp, in_ct==3?8:in_bd, out_ct==3?8:out_bd); |
|
|
|
processing = (vi.gamma_correction > 0 && !dp->threshold_test) |
|
|| in_bd != out_bd || in_ct != out_ct || vi.do_background; |
|
process_tRNS = dp->this.has_tRNS && vi.do_background; |
|
|
|
/* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside |
|
* the palette there is no way of finding out, because libpng fails to |
|
* update the palette on png_read_update_info. Indeed, libpng doesn't |
|
* even do the required work until much later, when it doesn't have any |
|
* info pointer. Oops. For the moment 'processing' is turned off if |
|
* out_ct is palette. |
|
*/ |
|
if (in_ct == 3 && out_ct == 3) |
|
processing = 0; |
|
|
|
if (processing && out_ct == 3) |
|
out_is_transparent = read_palette(out_palette, &out_npalette, pp, pi); |
|
|
|
for (y=0; y<h; ++y) |
|
{ |
|
png_const_bytep pRow = store_image_row(ps, pp, 0, y); |
|
png_byte std[STANDARD_ROWMAX]; |
|
|
|
transform_row(pp, std, in_ct, in_bd, y); |
|
|
|
if (processing) |
|
{ |
|
unsigned int x; |
|
|
|
for (x=0; x<w; ++x) |
|
{ |
|
double alpha = 1; /* serves as a flag value */ |
|
|
|
/* Record the palette index for index images. */ |
|
unsigned int in_index = |
|
in_ct == 3 ? sample(std, 3, in_bd, x, 0, 0, 0) : 256; |
|
unsigned int out_index = |
|
out_ct == 3 ? sample(std, 3, out_bd, x, 0, 0, 0) : 256; |
|
|
|
/* Handle input alpha - png_set_background will cause the output |
|
* alpha to disappear so there is nothing to check. |
|
*/ |
|
if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || |
|
(in_ct == 3 && in_is_transparent)) |
|
{ |
|
unsigned int input_alpha = in_ct == 3 ? |
|
dp->this.palette[in_index].alpha : |
|
sample(std, in_ct, in_bd, x, samples_per_pixel, 0, 0); |
|
|
|
unsigned int output_alpha = 65536 /* as a flag value */; |
|
|
|
if (out_ct == 3) |
|
{ |
|
if (out_is_transparent) |
|
output_alpha = out_palette[out_index].alpha; |
|
} |
|
|
|
else if ((out_ct & PNG_COLOR_MASK_ALPHA) != 0) |
|
output_alpha = sample(pRow, out_ct, out_bd, x, |
|
samples_per_pixel, 0, 0); |
|
|
|
if (output_alpha != 65536) |
|
alpha = gamma_component_validate("alpha", &vi, input_alpha, |
|
output_alpha, -1/*alpha*/, 0/*background*/); |
|
|
|
else /* no alpha in output */ |
|
{ |
|
/* This is a copy of the calculation of 'i' above in order to |
|
* have the alpha value to use in the background calculation. |
|
*/ |
|
alpha = input_alpha >> vi.isbit_shift; |
|
alpha /= vi.sbit_max; |
|
} |
|
} |
|
|
|
else if (process_tRNS) |
|
{ |
|
/* alpha needs to be set appropriately for this pixel, it is |
|
* currently 1 and needs to be 0 for an input pixel which matches |
|
* the values in tRNS. |
|
*/ |
|
switch (in_ct) |
|
{ |
|
case 0: /* gray */ |
|
if (sample(std, in_ct, in_bd, x, 0, 0, 0) == |
|
dp->this.transparent.red) |
|
alpha = 0; |
|
break; |
|
|
|
case 2: /* RGB */ |
|
if (sample(std, in_ct, in_bd, x, 0, 0, 0) == |
|
dp->this.transparent.red && |
|
sample(std, in_ct, in_bd, x, 1, 0, 0) == |
|
dp->this.transparent.green && |
|
sample(std, in_ct, in_bd, x, 2, 0, 0) == |
|
dp->this.transparent.blue) |
|
alpha = 0; |
|
break; |
|
|
|
default: |
|
break; |
|
} |
|
} |
|
|
|
/* Handle grayscale or RGB components. */ |
|
if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */ |
|
(void)gamma_component_validate("gray", &vi, |
|
sample(std, in_ct, in_bd, x, 0, 0, 0), |
|
sample(pRow, out_ct, out_bd, x, 0, 0, 0), |
|
alpha/*component*/, vi.background_red); |
|
else /* RGB or palette */ |
|
{ |
|
(void)gamma_component_validate("red", &vi, |
|
in_ct == 3 ? in_palette[in_index].red : |
|
sample(std, in_ct, in_bd, x, 0, 0, 0), |
|
out_ct == 3 ? out_palette[out_index].red : |
|
sample(pRow, out_ct, out_bd, x, 0, 0, 0), |
|
alpha/*component*/, vi.background_red); |
|
|
|
(void)gamma_component_validate("green", &vi, |
|
in_ct == 3 ? in_palette[in_index].green : |
|
sample(std, in_ct, in_bd, x, 1, 0, 0), |
|
out_ct == 3 ? out_palette[out_index].green : |
|
sample(pRow, out_ct, out_bd, x, 1, 0, 0), |
|
alpha/*component*/, vi.background_green); |
|
|
|
(void)gamma_component_validate("blue", &vi, |
|
in_ct == 3 ? in_palette[in_index].blue : |
|
sample(std, in_ct, in_bd, x, 2, 0, 0), |
|
out_ct == 3 ? out_palette[out_index].blue : |
|
sample(pRow, out_ct, out_bd, x, 2, 0, 0), |
|
alpha/*component*/, vi.background_blue); |
|
} |
|
} |
|
} |
|
|
|
else if (memcmp(std, pRow, cbRow) != 0) |
|
{ |
|
char msg[64]; |
|
|
|
/* No transform is expected on the threshold tests. */ |
|
sprintf(msg, "gamma: below threshold row %lu changed", |
|
(unsigned long)y); |
|
|
|
png_error(pp, msg); |
|
} |
|
} /* row (y) loop */ |
|
|
|
dp->this.ps->validated = 1; |
|
} |
|
|
|
static void PNGCBAPI |
|
gamma_end(png_structp ppIn, png_infop pi) |
|
{ |
|
png_const_structp pp = ppIn; |
|
gamma_display *dp = voidcast(gamma_display*, png_get_progressive_ptr(pp)); |
|
|
|
if (!dp->this.speed) |
|
gamma_image_validate(dp, pp, pi); |
|
else |
|
dp->this.ps->validated = 1; |
|
} |
|
|
|
/* A single test run checking a gamma transformation. |
|
* |
|
* maxabs: maximum absolute error as a fraction |
|
* maxout: maximum output error in the output units |
|
* maxpc: maximum percentage error (as a percentage) |
|
*/ |
|
static void |
|
gamma_test(png_modifier *pmIn, png_byte colour_typeIn, |
|
png_byte bit_depthIn, int palette_numberIn, |
|
int interlace_typeIn, |
|
const double file_gammaIn, const double screen_gammaIn, |
|
png_byte sbitIn, int threshold_testIn, |
|
const char *name, |
|
int use_input_precisionIn, int scale16In, |
|
int expand16In, int do_backgroundIn, |
|
const png_color_16 *bkgd_colorIn, double bkgd_gammaIn) |
|
{ |
|
gamma_display d; |
|
context(&pmIn->this, fault); |
|
|
|
gamma_display_init(&d, pmIn, FILEID(colour_typeIn, bit_depthIn, |
|
palette_numberIn, interlace_typeIn, 0, 0, 0), |
|
file_gammaIn, screen_gammaIn, sbitIn, |
|
threshold_testIn, use_input_precisionIn, scale16In, |
|
expand16In, do_backgroundIn, bkgd_colorIn, bkgd_gammaIn); |
|
|
|
Try |
|
{ |
|
png_structp pp; |
|
png_infop pi; |
|
gama_modification gama_mod; |
|
srgb_modification srgb_mod; |
|
sbit_modification sbit_mod; |
|
|
|
/* For the moment don't use the png_modifier support here. */ |
|
d.pm->encoding_counter = 0; |
|
modifier_set_encoding(d.pm); /* Just resets everything */ |
|
d.pm->current_gamma = d.file_gamma; |
|
|
|
/* Make an appropriate modifier to set the PNG file gamma to the |
|
* given gamma value and the sBIT chunk to the given precision. |
|
*/ |
|
d.pm->modifications = NULL; |
|
gama_modification_init(&gama_mod, d.pm, d.file_gamma); |
|
srgb_modification_init(&srgb_mod, d.pm, 127 /*delete*/); |
|
if (d.sbit > 0) |
|
sbit_modification_init(&sbit_mod, d.pm, d.sbit); |
|
|
|
modification_reset(d.pm->modifications); |
|
|
|
/* Get a png_struct for reading the image. */ |
|
pp = set_modifier_for_read(d.pm, &pi, d.this.id, name); |
|
standard_palette_init(&d.this); |
|
|
|
/* Introduce the correct read function. */ |
|
if (d.pm->this.progressive) |
|
{ |
|
/* Share the row function with the standard implementation. */ |
|
png_set_progressive_read_fn(pp, &d, gamma_info, progressive_row, |
|
gamma_end); |
|
|
|
/* Now feed data into the reader until we reach the end: */ |
|
modifier_progressive_read(d.pm, pp, pi); |
|
} |
|
else |
|
{ |
|
/* modifier_read expects a png_modifier* */ |
|
png_set_read_fn(pp, d.pm, modifier_read); |
|
|
|
/* Check the header values: */ |
|
png_read_info(pp, pi); |
|
|
|
/* Process the 'info' requirements. Only one image is generated */ |
|
gamma_info_imp(&d, pp, pi); |
|
|
|
sequential_row(&d.this, pp, pi, -1, 0); |
|
|
|
if (!d.this.speed) |
|
gamma_image_validate(&d, pp, pi); |
|
else |
|
d.this.ps->validated = 1; |
|
} |
|
|
|
modifier_reset(d.pm); |
|
|
|
if (d.pm->log && !d.threshold_test && !d.this.speed) |
|
fprintf(stderr, "%d bit %s %s: max error %f (%.2g, %2g%%)\n", |
|
d.this.bit_depth, colour_types[d.this.colour_type], name, |
|
d.maxerrout, d.maxerrabs, 100*d.maxerrpc); |
|
|
|
/* Log the summary values too. */ |
|
if (d.this.colour_type == 0 || d.this.colour_type == 4) |
|
{ |
|
switch (d.this.bit_depth) |
|
{ |
|
case 1: |
|
break; |
|
|
|
case 2: |
|
if (d.maxerrout > d.pm->error_gray_2) |
|
d.pm->error_gray_2 = d.maxerrout; |
|
|
|
break; |
|
|
|
case 4: |
|
if (d.maxerrout > d.pm->error_gray_4) |
|
d.pm->error_gray_4 = d.maxerrout; |
|
|
|
break; |
|
|
|
case 8: |
|
if (d.maxerrout > d.pm->error_gray_8) |
|
d.pm->error_gray_8 = d.maxerrout; |
|
|
|
break; |
|
|
|
case 16: |
|
if (d.maxerrout > d.pm->error_gray_16) |
|
d.pm->error_gray_16 = d.maxerrout; |
|
|
|
break; |
|
|
|
default: |
|
png_error(pp, "bad bit depth (internal: 1)"); |
|
} |
|
} |
|
|
|
else if (d.this.colour_type == 2 || d.this.colour_type == 6) |
|
{ |
|
switch (d.this.bit_depth) |
|
{ |
|
case 8: |
|
|
|
if (d.maxerrout > d.pm->error_color_8) |
|
d.pm->error_color_8 = d.maxerrout; |
|
|
|
break; |
|
|
|
case 16: |
|
|
|
if (d.maxerrout > d.pm->error_color_16) |
|
d.pm->error_color_16 = d.maxerrout; |
|
|
|
break; |
|
|
|
default: |
|
png_error(pp, "bad bit depth (internal: 2)"); |
|
} |
|
} |
|
|
|
else if (d.this.colour_type == 3) |
|
{ |
|
if (d.maxerrout > d.pm->error_indexed) |
|
d.pm->error_indexed = d.maxerrout; |
|
} |
|
} |
|
|
|
Catch(fault) |
|
modifier_reset(voidcast(png_modifier*,(void*)fault)); |
|
} |
|
|
|
static void gamma_threshold_test(png_modifier *pm, png_byte colour_type, |
|
png_byte bit_depth, int interlace_type, double file_gamma, |
|
double screen_gamma) |
|
{ |
|
size_t pos = 0; |
|
char name[64]; |
|
pos = safecat(name, sizeof name, pos, "threshold "); |
|
pos = safecatd(name, sizeof name, pos, file_gamma, 3); |
|
pos = safecat(name, sizeof name, pos, "/"); |
|
pos = safecatd(name, sizeof name, pos, screen_gamma, 3); |
|
|
|
(void)gamma_test(pm, colour_type, bit_depth, 0/*palette*/, interlace_type, |
|
file_gamma, screen_gamma, 0/*sBIT*/, 1/*threshold test*/, name, |
|
0 /*no input precision*/, |
|
0 /*no scale16*/, 0 /*no expand16*/, 0 /*no background*/, 0 /*hence*/, |
|
0 /*no background gamma*/); |
|
} |
|
|
|
static void |
|
perform_gamma_threshold_tests(png_modifier *pm) |
|
{ |
|
png_byte colour_type = 0; |
|
png_byte bit_depth = 0; |
|
unsigned int palette_number = 0; |
|
|
|
/* Don't test more than one instance of each palette - it's pointless, in |
|
* fact this test is somewhat excessive since libpng doesn't make this |
|
* decision based on colour type or bit depth! |
|
* |
|
* CHANGED: now test two palettes and, as a side effect, images with and |
|
* without tRNS. |
|
*/ |
|
while (next_format(&colour_type, &bit_depth, &palette_number, |
|
pm->test_lbg_gamma_threshold, pm->test_tRNS)) |
|
if (palette_number < 2) |
|
{ |
|
double test_gamma = 1.0; |
|
while (test_gamma >= .4) |
|
{ |
|
/* There's little point testing the interlacing vs non-interlacing, |
|
* but this can be set from the command line. |
|
*/ |
|
gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, |
|
test_gamma, 1/test_gamma); |
|
test_gamma *= .95; |
|
} |
|
|
|
/* And a special test for sRGB */ |
|
gamma_threshold_test(pm, colour_type, bit_depth, pm->interlace_type, |
|
.45455, 2.2); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
} |
|
|
|
static void gamma_transform_test(png_modifier *pm, |
|
png_byte colour_type, png_byte bit_depth, |
|
int palette_number, |
|
int interlace_type, const double file_gamma, |
|
const double screen_gamma, png_byte sbit, |
|
int use_input_precision, int scale16) |
|
{ |
|
size_t pos = 0; |
|
char name[64]; |
|
|
|
if (sbit != bit_depth && sbit != 0) |
|
{ |
|
pos = safecat(name, sizeof name, pos, "sbit("); |
|
pos = safecatn(name, sizeof name, pos, sbit); |
|
pos = safecat(name, sizeof name, pos, ") "); |
|
} |
|
|
|
else |
|
pos = safecat(name, sizeof name, pos, "gamma "); |
|
|
|
if (scale16) |
|
pos = safecat(name, sizeof name, pos, "16to8 "); |
|
|
|
pos = safecatd(name, sizeof name, pos, file_gamma, 3); |
|
pos = safecat(name, sizeof name, pos, "->"); |
|
pos = safecatd(name, sizeof name, pos, screen_gamma, 3); |
|
|
|
gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, |
|
file_gamma, screen_gamma, sbit, 0, name, use_input_precision, |
|
scale16, pm->test_gamma_expand16, 0 , 0, 0); |
|
} |
|
|
|
static void perform_gamma_transform_tests(png_modifier *pm) |
|
{ |
|
png_byte colour_type = 0; |
|
png_byte bit_depth = 0; |
|
unsigned int palette_number = 0; |
|
|
|
while (next_format(&colour_type, &bit_depth, &palette_number, |
|
pm->test_lbg_gamma_transform, pm->test_tRNS)) |
|
{ |
|
unsigned int i, j; |
|
|
|
for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) |
|
if (i != j) |
|
{ |
|
gamma_transform_test(pm, colour_type, bit_depth, palette_number, |
|
pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], 0/*sBIT*/, |
|
pm->use_input_precision, 0 /*do not scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
} |
|
} |
|
|
|
static void perform_gamma_sbit_tests(png_modifier *pm) |
|
{ |
|
png_byte sbit; |
|
|
|
/* The only interesting cases are colour and grayscale, alpha is ignored here |
|
* for overall speed. Only bit depths where sbit is less than the bit depth |
|
* are tested. |
|
*/ |
|
for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit) |
|
{ |
|
png_byte colour_type = 0, bit_depth = 0; |
|
unsigned int npalette = 0; |
|
|
|
while (next_format(&colour_type, &bit_depth, &npalette, |
|
pm->test_lbg_gamma_sbit, pm->test_tRNS)) |
|
if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 && |
|
((colour_type == 3 && sbit < 8) || |
|
(colour_type != 3 && sbit < bit_depth))) |
|
{ |
|
unsigned int i; |
|
|
|
for (i=0; i<pm->ngamma_tests; ++i) |
|
{ |
|
unsigned int j; |
|
|
|
for (j=0; j<pm->ngamma_tests; ++j) if (i != j) |
|
{ |
|
gamma_transform_test(pm, colour_type, bit_depth, npalette, |
|
pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], |
|
sbit, pm->use_input_precision_sbit, 0 /*scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
} |
|
} |
|
} |
|
} |
|
|
|
/* Note that this requires a 16 bit source image but produces 8 bit output, so |
|
* we only need the 16bit write support, but the 16 bit images are only |
|
* generated if DO_16BIT is defined. |
|
*/ |
|
#ifdef DO_16BIT |
|
static void perform_gamma_scale16_tests(png_modifier *pm) |
|
{ |
|
# ifndef PNG_MAX_GAMMA_8 |
|
# define PNG_MAX_GAMMA_8 11 |
|
# endif |
|
# if defined PNG_MAX_GAMMA_8 || PNG_LIBPNG_VER < 10700 |
|
# define SBIT_16_TO_8 PNG_MAX_GAMMA_8 |
|
# else |
|
# define SBIT_16_TO_8 16 |
|
# endif |
|
/* Include the alpha cases here. Note that sbit matches the internal value |
|
* used by the library - otherwise we will get spurious errors from the |
|
* internal sbit style approximation. |
|
* |
|
* The threshold test is here because otherwise the 16 to 8 conversion will |
|
* proceed *without* gamma correction, and the tests above will fail (but not |
|
* by much) - this could be fixed, it only appears with the -g option. |
|
*/ |
|
unsigned int i, j; |
|
for (i=0; i<pm->ngamma_tests; ++i) |
|
{ |
|
for (j=0; j<pm->ngamma_tests; ++j) |
|
{ |
|
if (i != j && |
|
fabs(pm->gammas[j]/pm->gammas[i]-1) >= PNG_GAMMA_THRESHOLD) |
|
{ |
|
gamma_transform_test(pm, 0, 16, 0, pm->interlace_type, |
|
1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, |
|
pm->use_input_precision_16to8, 1 /*scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
|
|
gamma_transform_test(pm, 2, 16, 0, pm->interlace_type, |
|
1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, |
|
pm->use_input_precision_16to8, 1 /*scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
|
|
gamma_transform_test(pm, 4, 16, 0, pm->interlace_type, |
|
1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, |
|
pm->use_input_precision_16to8, 1 /*scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
|
|
gamma_transform_test(pm, 6, 16, 0, pm->interlace_type, |
|
1/pm->gammas[i], pm->gammas[j], SBIT_16_TO_8, |
|
pm->use_input_precision_16to8, 1 /*scale16*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
} |
|
} |
|
} |
|
#endif /* 16 to 8 bit conversion */ |
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
|
defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
|
static void gamma_composition_test(png_modifier *pm, |
|
png_byte colour_type, png_byte bit_depth, |
|
int palette_number, |
|
int interlace_type, const double file_gamma, |
|
const double screen_gamma, |
|
int use_input_precision, int do_background, |
|
int expand_16) |
|
{ |
|
size_t pos = 0; |
|
png_const_charp base; |
|
double bg; |
|
char name[128]; |
|
png_color_16 background; |
|
|
|
/* Make up a name and get an appropriate background gamma value. */ |
|
switch (do_background) |
|
{ |
|
default: |
|
base = ""; |
|
bg = 4; /* should not be used */ |
|
break; |
|
case PNG_BACKGROUND_GAMMA_SCREEN: |
|
base = " bckg(Screen):"; |
|
bg = 1/screen_gamma; |
|
break; |
|
case PNG_BACKGROUND_GAMMA_FILE: |
|
base = " bckg(File):"; |
|
bg = file_gamma; |
|
break; |
|
case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
base = " bckg(Unique):"; |
|
/* This tests the handling of a unique value, the math is such that the |
|
* value tends to be <1, but is neither screen nor file (even if they |
|
* match!) |
|
*/ |
|
bg = (file_gamma + screen_gamma) / 3; |
|
break; |
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_PNG: |
|
base = " alpha(PNG)"; |
|
bg = 4; /* should not be used */ |
|
break; |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: |
|
base = " alpha(Porter-Duff)"; |
|
bg = 4; /* should not be used */ |
|
break; |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: |
|
base = " alpha(Optimized)"; |
|
bg = 4; /* should not be used */ |
|
break; |
|
case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: |
|
base = " alpha(Broken)"; |
|
bg = 4; /* should not be used */ |
|
break; |
|
#endif |
|
} |
|
|
|
/* Use random background values - the background is always presented in the |
|
* output space (8 or 16 bit components). |
|
*/ |
|
if (expand_16 || bit_depth == 16) |
|
{ |
|
png_uint_32 r = random_32(); |
|
|
|
background.red = (png_uint_16)r; |
|
background.green = (png_uint_16)(r >> 16); |
|
r = random_32(); |
|
background.blue = (png_uint_16)r; |
|
background.gray = (png_uint_16)(r >> 16); |
|
|
|
/* In earlier libpng versions, those where DIGITIZE is set, any background |
|
* gamma correction in the expand16 case was done using 8-bit gamma |
|
* correction tables, resulting in larger errors. To cope with those |
|
* cases use a 16-bit background value which will handle this gamma |
|
* correction. |
|
*/ |
|
# if DIGITIZE |
|
if (expand_16 && (do_background == PNG_BACKGROUND_GAMMA_UNIQUE || |
|
do_background == PNG_BACKGROUND_GAMMA_FILE) && |
|
fabs(bg*screen_gamma-1) > PNG_GAMMA_THRESHOLD) |
|
{ |
|
/* The background values will be looked up in an 8-bit table to do |
|
* the gamma correction, so only select values which are an exact |
|
* match for the 8-bit table entries: |
|
*/ |
|
background.red = (png_uint_16)((background.red >> 8) * 257); |
|
background.green = (png_uint_16)((background.green >> 8) * 257); |
|
background.blue = (png_uint_16)((background.blue >> 8) * 257); |
|
background.gray = (png_uint_16)((background.gray >> 8) * 257); |
|
} |
|
# endif |
|
} |
|
|
|
else /* 8 bit colors */ |
|
{ |
|
png_uint_32 r = random_32(); |
|
|
|
background.red = (png_byte)r; |
|
background.green = (png_byte)(r >> 8); |
|
background.blue = (png_byte)(r >> 16); |
|
background.gray = (png_byte)(r >> 24); |
|
} |
|
|
|
background.index = 193; /* rgb(193,193,193) to detect errors */ |
|
|
|
if (!(colour_type & PNG_COLOR_MASK_COLOR)) |
|
{ |
|
/* Because, currently, png_set_background is always called with |
|
* 'need_expand' false in this case and because the gamma test itself |
|
* doesn't cause an expand to 8-bit for lower bit depths the colour must |
|
* be reduced to the correct range. |
|
*/ |
|
if (bit_depth < 8) |
|
background.gray &= (png_uint_16)((1U << bit_depth)-1); |
|
|
|
/* Grayscale input, we do not convert to RGB (TBD), so we must set the |
|
* background to gray - else libpng seems to fail. |
|
*/ |
|
background.red = background.green = background.blue = background.gray; |
|
} |
|
|
|
pos = safecat(name, sizeof name, pos, "gamma "); |
|
pos = safecatd(name, sizeof name, pos, file_gamma, 3); |
|
pos = safecat(name, sizeof name, pos, "->"); |
|
pos = safecatd(name, sizeof name, pos, screen_gamma, 3); |
|
|
|
pos = safecat(name, sizeof name, pos, base); |
|
if (do_background < ALPHA_MODE_OFFSET) |
|
{ |
|
/* Include the background color and gamma in the name: */ |
|
pos = safecat(name, sizeof name, pos, "("); |
|
/* This assumes no expand gray->rgb - the current code won't handle that! |
|
*/ |
|
if (colour_type & PNG_COLOR_MASK_COLOR) |
|
{ |
|
pos = safecatn(name, sizeof name, pos, background.red); |
|
pos = safecat(name, sizeof name, pos, ","); |
|
pos = safecatn(name, sizeof name, pos, background.green); |
|
pos = safecat(name, sizeof name, pos, ","); |
|
pos = safecatn(name, sizeof name, pos, background.blue); |
|
} |
|
else |
|
pos = safecatn(name, sizeof name, pos, background.gray); |
|
pos = safecat(name, sizeof name, pos, ")^"); |
|
pos = safecatd(name, sizeof name, pos, bg, 3); |
|
} |
|
|
|
gamma_test(pm, colour_type, bit_depth, palette_number, interlace_type, |
|
file_gamma, screen_gamma, 0/*sBIT*/, 0, name, use_input_precision, |
|
0/*strip 16*/, expand_16, do_background, &background, bg); |
|
} |
|
|
|
|
|
static void |
|
perform_gamma_composition_tests(png_modifier *pm, int do_background, |
|
int expand_16) |
|
{ |
|
png_byte colour_type = 0; |
|
png_byte bit_depth = 0; |
|
unsigned int palette_number = 0; |
|
|
|
/* Skip the non-alpha cases - there is no setting of a transparency colour at |
|
* present. |
|
* |
|
* TODO: incorrect; the palette case sets tRNS and, now RGB and gray do, |
|
* however the palette case fails miserably so is commented out below. |
|
*/ |
|
while (next_format(&colour_type, &bit_depth, &palette_number, |
|
pm->test_lbg_gamma_composition, pm->test_tRNS)) |
|
if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0 |
|
#if 0 /* TODO: FIXME */ |
|
/*TODO: FIXME: this should work */ |
|
|| colour_type == 3 |
|
#endif |
|
|| (colour_type != 3 && palette_number != 0)) |
|
{ |
|
unsigned int i, j; |
|
|
|
/* Don't skip the i==j case here - it's relevant. */ |
|
for (i=0; i<pm->ngamma_tests; ++i) for (j=0; j<pm->ngamma_tests; ++j) |
|
{ |
|
gamma_composition_test(pm, colour_type, bit_depth, palette_number, |
|
pm->interlace_type, 1/pm->gammas[i], pm->gammas[j], |
|
pm->use_input_precision, do_background, expand_16); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
} |
|
} |
|
#endif /* READ_BACKGROUND || READ_ALPHA_MODE */ |
|
|
|
static void |
|
init_gamma_errors(png_modifier *pm) |
|
{ |
|
/* Use -1 to catch tests that were not actually run */ |
|
pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = -1.; |
|
pm->error_color_8 = -1.; |
|
pm->error_indexed = -1.; |
|
pm->error_gray_16 = pm->error_color_16 = -1.; |
|
} |
|
|
|
static void |
|
print_one(const char *leader, double err) |
|
{ |
|
if (err != -1.) |
|
printf(" %s %.5f\n", leader, err); |
|
} |
|
|
|
static void |
|
summarize_gamma_errors(png_modifier *pm, png_const_charp who, int low_bit_depth, |
|
int indexed) |
|
{ |
|
fflush(stderr); |
|
|
|
if (who) |
|
printf("\nGamma correction with %s:\n", who); |
|
|
|
else |
|
printf("\nBasic gamma correction:\n"); |
|
|
|
if (low_bit_depth) |
|
{ |
|
print_one(" 2 bit gray: ", pm->error_gray_2); |
|
print_one(" 4 bit gray: ", pm->error_gray_4); |
|
print_one(" 8 bit gray: ", pm->error_gray_8); |
|
print_one(" 8 bit color:", pm->error_color_8); |
|
if (indexed) |
|
print_one(" indexed: ", pm->error_indexed); |
|
} |
|
|
|
print_one("16 bit gray: ", pm->error_gray_16); |
|
print_one("16 bit color:", pm->error_color_16); |
|
|
|
fflush(stdout); |
|
} |
|
|
|
static void |
|
perform_gamma_test(png_modifier *pm, int summary) |
|
{ |
|
/*TODO: remove this*/ |
|
/* Save certain values for the temporary overrides below. */ |
|
unsigned int calculations_use_input_precision = |
|
pm->calculations_use_input_precision; |
|
# ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
double maxout8 = pm->maxout8; |
|
# endif |
|
|
|
/* First some arbitrary no-transform tests: */ |
|
if (!pm->this.speed && pm->test_gamma_threshold) |
|
{ |
|
perform_gamma_threshold_tests(pm); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
|
|
/* Now some real transforms. */ |
|
if (pm->test_gamma_transform) |
|
{ |
|
if (summary) |
|
{ |
|
fflush(stderr); |
|
printf("Gamma correction error summary\n\n"); |
|
printf("The printed value is the maximum error in the pixel values\n"); |
|
printf("calculated by the libpng gamma correction code. The error\n"); |
|
printf("is calculated as the difference between the output pixel\n"); |
|
printf("value (always an integer) and the ideal value from the\n"); |
|
printf("libpng specification (typically not an integer).\n\n"); |
|
|
|
printf("Expect this value to be less than .5 for 8 bit formats,\n"); |
|
printf("less than 1 for formats with fewer than 8 bits and a small\n"); |
|
printf("number (typically less than 5) for the 16 bit formats.\n"); |
|
printf("For performance reasons the value for 16 bit formats\n"); |
|
printf("increases when the image file includes an sBIT chunk.\n"); |
|
fflush(stdout); |
|
} |
|
|
|
init_gamma_errors(pm); |
|
/*TODO: remove this. Necessary because the current libpng |
|
* implementation works in 8 bits: |
|
*/ |
|
if (pm->test_gamma_expand16) |
|
pm->calculations_use_input_precision = 1; |
|
perform_gamma_transform_tests(pm); |
|
if (!calculations_use_input_precision) |
|
pm->calculations_use_input_precision = 0; |
|
|
|
if (summary) |
|
summarize_gamma_errors(pm, 0/*who*/, 1/*low bit depth*/, 1/*indexed*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
|
|
/* The sbit tests produce much larger errors: */ |
|
if (pm->test_gamma_sbit) |
|
{ |
|
init_gamma_errors(pm); |
|
perform_gamma_sbit_tests(pm); |
|
|
|
if (summary) |
|
summarize_gamma_errors(pm, "sBIT", pm->sbitlow < 8U, 1/*indexed*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
|
|
#ifdef DO_16BIT /* Should be READ_16BIT_SUPPORTED */ |
|
if (pm->test_gamma_scale16) |
|
{ |
|
/* The 16 to 8 bit strip operations: */ |
|
init_gamma_errors(pm); |
|
perform_gamma_scale16_tests(pm); |
|
|
|
if (summary) |
|
{ |
|
fflush(stderr); |
|
printf("\nGamma correction with 16 to 8 bit reduction:\n"); |
|
printf(" 16 bit gray: %.5f\n", pm->error_gray_16); |
|
printf(" 16 bit color: %.5f\n", pm->error_color_16); |
|
fflush(stdout); |
|
} |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_BACKGROUND_SUPPORTED |
|
if (pm->test_gamma_background) |
|
{ |
|
init_gamma_errors(pm); |
|
|
|
/*TODO: remove this. Necessary because the current libpng |
|
* implementation works in 8 bits: |
|
*/ |
|
if (pm->test_gamma_expand16) |
|
{ |
|
pm->calculations_use_input_precision = 1; |
|
pm->maxout8 = .499; /* because the 16 bit background is smashed */ |
|
} |
|
perform_gamma_composition_tests(pm, PNG_BACKGROUND_GAMMA_UNIQUE, |
|
pm->test_gamma_expand16); |
|
if (!calculations_use_input_precision) |
|
pm->calculations_use_input_precision = 0; |
|
pm->maxout8 = maxout8; |
|
|
|
if (summary) |
|
summarize_gamma_errors(pm, "background", 1, 0/*indexed*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
#endif |
|
|
|
#ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
|
if (pm->test_gamma_alpha_mode) |
|
{ |
|
int do_background; |
|
|
|
init_gamma_errors(pm); |
|
|
|
/*TODO: remove this. Necessary because the current libpng |
|
* implementation works in 8 bits: |
|
*/ |
|
if (pm->test_gamma_expand16) |
|
pm->calculations_use_input_precision = 1; |
|
for (do_background = ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD; |
|
do_background <= ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN && !fail(pm); |
|
++do_background) |
|
perform_gamma_composition_tests(pm, do_background, |
|
pm->test_gamma_expand16); |
|
if (!calculations_use_input_precision) |
|
pm->calculations_use_input_precision = 0; |
|
|
|
if (summary) |
|
summarize_gamma_errors(pm, "alpha mode", 1, 0/*indexed*/); |
|
|
|
if (fail(pm)) |
|
return; |
|
} |
|
#endif |
|
} |
|
#endif /* PNG_READ_GAMMA_SUPPORTED */ |
|
#endif /* PNG_READ_SUPPORTED */ |
|
|
|
/* INTERLACE MACRO VALIDATION */ |
|
/* This is copied verbatim from the specification, it is simply the pass |
|
* number in which each pixel in each 8x8 tile appears. The array must |
|
* be indexed adam7[y][x] and notice that the pass numbers are based at |
|
* 1, not 0 - the base libpng uses. |
|
*/ |
|
static const |
|
png_byte adam7[8][8] = |
|
{ |
|
{ 1,6,4,6,2,6,4,6 }, |
|
{ 7,7,7,7,7,7,7,7 }, |
|
{ 5,6,5,6,5,6,5,6 }, |
|
{ 7,7,7,7,7,7,7,7 }, |
|
{ 3,6,4,6,3,6,4,6 }, |
|
{ 7,7,7,7,7,7,7,7 }, |
|
{ 5,6,5,6,5,6,5,6 }, |
|
{ 7,7,7,7,7,7,7,7 } |
|
}; |
|
|
|
/* This routine validates all the interlace support macros in png.h for |
|
* a variety of valid PNG widths and heights. It uses a number of similarly |
|
* named internal routines that feed off the above array. |
|
*/ |
|
static png_uint_32 |
|
png_pass_start_row(int pass) |
|
{ |
|
int x, y; |
|
++pass; |
|
for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) |
|
return y; |
|
return 0xf; |
|
} |
|
|
|
static png_uint_32 |
|
png_pass_start_col(int pass) |
|
{ |
|
int x, y; |
|
++pass; |
|
for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) |
|
return x; |
|
return 0xf; |
|
} |
|
|
|
static int |
|
png_pass_row_shift(int pass) |
|
{ |
|
int x, y, base=(-1), inc=8; |
|
++pass; |
|
for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) |
|
{ |
|
if (base == (-1)) |
|
base = y; |
|
else if (base == y) |
|
{} |
|
else if (inc == y-base) |
|
base=y; |
|
else if (inc == 8) |
|
inc = y-base, base=y; |
|
else if (inc != y-base) |
|
return 0xff; /* error - more than one 'inc' value! */ |
|
} |
|
|
|
if (base == (-1)) return 0xfe; /* error - no row in pass! */ |
|
|
|
/* The shift is always 1, 2 or 3 - no pass has all the rows! */ |
|
switch (inc) |
|
{ |
|
case 2: return 1; |
|
case 4: return 2; |
|
case 8: return 3; |
|
default: break; |
|
} |
|
|
|
/* error - unrecognized 'inc' */ |
|
return (inc << 8) + 0xfd; |
|
} |
|
|
|
static int |
|
png_pass_col_shift(int pass) |
|
{ |
|
int x, y, base=(-1), inc=8; |
|
++pass; |
|
for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) |
|
{ |
|
if (base == (-1)) |
|
base = x; |
|
else if (base == x) |
|
{} |
|
else if (inc == x-base) |
|
base=x; |
|
else if (inc == 8) |
|
inc = x-base, base=x; |
|
else if (inc != x-base) |
|
return 0xff; /* error - more than one 'inc' value! */ |
|
} |
|
|
|
if (base == (-1)) return 0xfe; /* error - no row in pass! */ |
|
|
|
/* The shift is always 1, 2 or 3 - no pass has all the rows! */ |
|
switch (inc) |
|
{ |
|
case 1: return 0; /* pass 7 has all the columns */ |
|
case 2: return 1; |
|
case 4: return 2; |
|
case 8: return 3; |
|
default: break; |
|
} |
|
|
|
/* error - unrecognized 'inc' */ |
|
return (inc << 8) + 0xfd; |
|
} |
|
|
|
static png_uint_32 |
|
png_row_from_pass_row(png_uint_32 yIn, int pass) |
|
{ |
|
/* By examination of the array: */ |
|
switch (pass) |
|
{ |
|
case 0: return yIn * 8; |
|
case 1: return yIn * 8; |
|
case 2: return yIn * 8 + 4; |
|
case 3: return yIn * 4; |
|
case 4: return yIn * 4 + 2; |
|
case 5: return yIn * 2; |
|
case 6: return yIn * 2 + 1; |
|
default: break; |
|
} |
|
|
|
return 0xff; /* bad pass number */ |
|
} |
|
|
|
static png_uint_32 |
|
png_col_from_pass_col(png_uint_32 xIn, int pass) |
|
{ |
|
/* By examination of the array: */ |
|
switch (pass) |
|
{ |
|
case 0: return xIn * 8; |
|
case 1: return xIn * 8 + 4; |
|
case 2: return xIn * 4; |
|
case 3: return xIn * 4 + 2; |
|
case 4: return xIn * 2; |
|
case 5: return xIn * 2 + 1; |
|
case 6: return xIn; |
|
default: break; |
|
} |
|
|
|
return 0xff; /* bad pass number */ |
|
} |
|
|
|
static int |
|
png_row_in_interlace_pass(png_uint_32 y, int pass) |
|
{ |
|
/* Is row 'y' in pass 'pass'? */ |
|
int x; |
|
y &= 7; |
|
++pass; |
|
for (x=0; x<8; ++x) if (adam7[y][x] == pass) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
static int |
|
png_col_in_interlace_pass(png_uint_32 x, int pass) |
|
{ |
|
/* Is column 'x' in pass 'pass'? */ |
|
int y; |
|
x &= 7; |
|
++pass; |
|
for (y=0; y<8; ++y) if (adam7[y][x] == pass) |
|
return 1; |
|
|
|
return 0; |
|
} |
|
|
|
static png_uint_32 |
|
png_pass_rows(png_uint_32 height, int pass) |
|
{ |
|
png_uint_32 tiles = height>>3; |
|
png_uint_32 rows = 0; |
|
unsigned int x, y; |
|
|
|
height &= 7; |
|
++pass; |
|
for (y=0; y<8; ++y) for (x=0; x<8; ++x) if (adam7[y][x] == pass) |
|
{ |
|
rows += tiles; |
|
if (y < height) ++rows; |
|
break; /* i.e. break the 'x', column, loop. */ |
|
} |
|
|
|
return rows; |
|
} |
|
|
|
static png_uint_32 |
|
png_pass_cols(png_uint_32 width, int pass) |
|
{ |
|
png_uint_32 tiles = width>>3; |
|
png_uint_32 cols = 0; |
|
unsigned int x, y; |
|
|
|
width &= 7; |
|
++pass; |
|
for (x=0; x<8; ++x) for (y=0; y<8; ++y) if (adam7[y][x] == pass) |
|
{ |
|
cols += tiles; |
|
if (x < width) ++cols; |
|
break; /* i.e. break the 'y', row, loop. */ |
|
} |
|
|
|
return cols; |
|
} |
|
|
|
static void |
|
perform_interlace_macro_validation(void) |
|
{ |
|
/* The macros to validate, first those that depend only on pass: |
|
* |
|
* PNG_PASS_START_ROW(pass) |
|
* PNG_PASS_START_COL(pass) |
|
* PNG_PASS_ROW_SHIFT(pass) |
|
* PNG_PASS_COL_SHIFT(pass) |
|
*/ |
|
int pass; |
|
|
|
for (pass=0; pass<7; ++pass) |
|
{ |
|
png_uint_32 m, f, v; |
|
|
|
m = PNG_PASS_START_ROW(pass); |
|
f = png_pass_start_row(pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_START_ROW(%d) = %u != %x\n", pass, m, f); |
|
exit(99); |
|
} |
|
|
|
m = PNG_PASS_START_COL(pass); |
|
f = png_pass_start_col(pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_START_COL(%d) = %u != %x\n", pass, m, f); |
|
exit(99); |
|
} |
|
|
|
m = PNG_PASS_ROW_SHIFT(pass); |
|
f = png_pass_row_shift(pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_ROW_SHIFT(%d) = %u != %x\n", pass, m, f); |
|
exit(99); |
|
} |
|
|
|
m = PNG_PASS_COL_SHIFT(pass); |
|
f = png_pass_col_shift(pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_COL_SHIFT(%d) = %u != %x\n", pass, m, f); |
|
exit(99); |
|
} |
|
|
|
/* Macros that depend on the image or sub-image height too: |
|
* |
|
* PNG_PASS_ROWS(height, pass) |
|
* PNG_PASS_COLS(width, pass) |
|
* PNG_ROW_FROM_PASS_ROW(yIn, pass) |
|
* PNG_COL_FROM_PASS_COL(xIn, pass) |
|
* PNG_ROW_IN_INTERLACE_PASS(y, pass) |
|
* PNG_COL_IN_INTERLACE_PASS(x, pass) |
|
*/ |
|
for (v=0;;) |
|
{ |
|
/* The first two tests overflow if the pass row or column is outside |
|
* the possible range for a 32-bit result. In fact the values should |
|
* never be outside the range for a 31-bit result, but checking for 32 |
|
* bits here ensures that if an app uses a bogus pass row or column |
|
* (just so long as it fits in a 32 bit integer) it won't get a |
|
* possibly dangerous overflow. |
|
*/ |
|
/* First the base 0 stuff: */ |
|
if (v < png_pass_rows(0xFFFFFFFFU, pass)) |
|
{ |
|
m = PNG_ROW_FROM_PASS_ROW(v, pass); |
|
f = png_row_from_pass_row(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_ROW_FROM_PASS_ROW(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
} |
|
|
|
if (v < png_pass_cols(0xFFFFFFFFU, pass)) |
|
{ |
|
m = PNG_COL_FROM_PASS_COL(v, pass); |
|
f = png_col_from_pass_col(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_COL_FROM_PASS_COL(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
} |
|
|
|
m = PNG_ROW_IN_INTERLACE_PASS(v, pass); |
|
f = png_row_in_interlace_pass(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_ROW_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
|
|
m = PNG_COL_IN_INTERLACE_PASS(v, pass); |
|
f = png_col_in_interlace_pass(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_COL_IN_INTERLACE_PASS(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
|
|
/* Then the base 1 stuff: */ |
|
++v; |
|
m = PNG_PASS_ROWS(v, pass); |
|
f = png_pass_rows(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_ROWS(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
|
|
m = PNG_PASS_COLS(v, pass); |
|
f = png_pass_cols(v, pass); |
|
if (m != f) |
|
{ |
|
fprintf(stderr, "PNG_PASS_COLS(%u, %d) = %u != %x\n", |
|
v, pass, m, f); |
|
exit(99); |
|
} |
|
|
|
/* Move to the next v - the stepping algorithm starts skipping |
|
* values above 1024. |
|
*/ |
|
if (v > 1024) |
|
{ |
|
if (v == PNG_UINT_31_MAX) |
|
break; |
|
|
|
v = (v << 1) ^ v; |
|
if (v >= PNG_UINT_31_MAX) |
|
v = PNG_UINT_31_MAX-1; |
|
} |
|
} |
|
} |
|
} |
|
|
|
/* Test color encodings. These values are back-calculated from the published |
|
* chromaticities. The values are accurate to about 14 decimal places; 15 are |
|
* given. These values are much more accurate than the ones given in the spec, |
|
* which typically don't exceed 4 decimal places. This allows testing of the |
|
* libpng code to its theoretical accuracy of 4 decimal places. (If pngvalid |
|
* used the published errors the 'slack' permitted would have to be +/-.5E-4 or |
|
* more.) |
|
* |
|
* The png_modifier code assumes that encodings[0] is sRGB and treats it |
|
* specially: do not change the first entry in this list! |
|
*/ |
|
static const color_encoding test_encodings[] = |
|
{ |
|
/* sRGB: must be first in this list! */ |
|
/*gamma:*/ { 1/2.2, |
|
/*red: */ { 0.412390799265959, 0.212639005871510, 0.019330818715592 }, |
|
/*green:*/ { 0.357584339383878, 0.715168678767756, 0.119194779794626 }, |
|
/*blue: */ { 0.180480788401834, 0.072192315360734, 0.950532152249660} }, |
|
/* Kodak ProPhoto (wide gamut) */ |
|
/*gamma:*/ { 1/1.6 /*approximate: uses 1.8 power law compared to sRGB 2.4*/, |
|
/*red: */ { 0.797760489672303, 0.288071128229293, 0.000000000000000 }, |
|
/*green:*/ { 0.135185837175740, 0.711843217810102, 0.000000000000000 }, |
|
/*blue: */ { 0.031349349581525, 0.000085653960605, 0.825104602510460} }, |
|
/* Adobe RGB (1998) */ |
|
/*gamma:*/ { 1/(2+51./256), |
|
/*red: */ { 0.576669042910131, 0.297344975250536, 0.027031361386412 }, |
|
/*green:*/ { 0.185558237906546, 0.627363566255466, 0.070688852535827 }, |
|
/*blue: */ { 0.188228646234995, 0.075291458493998, 0.991337536837639} }, |
|
/* Adobe Wide Gamut RGB */ |
|
/*gamma:*/ { 1/(2+51./256), |
|
/*red: */ { 0.716500716779386, 0.258728243040113, 0.000000000000000 }, |
|
/*green:*/ { 0.101020574397477, 0.724682314948566, 0.051211818965388 }, |
|
/*blue: */ { 0.146774385252705, 0.016589442011321, 0.773892783545073} }, |
|
/* Fake encoding which selects just the green channel */ |
|
/*gamma:*/ { 1.45/2.2, /* the 'Mac' gamma */ |
|
/*red: */ { 0.716500716779386, 0.000000000000000, 0.000000000000000 }, |
|
/*green:*/ { 0.101020574397477, 1.000000000000000, 0.051211818965388 }, |
|
/*blue: */ { 0.146774385252705, 0.000000000000000, 0.773892783545073} }, |
|
}; |
|
|
|
/* signal handler |
|
* |
|
* This attempts to trap signals and escape without crashing. It needs a |
|
* context pointer so that it can throw an exception (call longjmp) to recover |
|
* from the condition; this is handled by making the png_modifier used by 'main' |
|
* into a global variable. |
|
*/ |
|
static png_modifier pm; |
|
|
|
static void signal_handler(int signum) |
|
{ |
|
|
|
size_t pos = 0; |
|
char msg[64]; |
|
|
|
pos = safecat(msg, sizeof msg, pos, "caught signal: "); |
|
|
|
switch (signum) |
|
{ |
|
case SIGABRT: |
|
pos = safecat(msg, sizeof msg, pos, "abort"); |
|
break; |
|
|
|
case SIGFPE: |
|
pos = safecat(msg, sizeof msg, pos, "floating point exception"); |
|
break; |
|
|
|
case SIGILL: |
|
pos = safecat(msg, sizeof msg, pos, "illegal instruction"); |
|
break; |
|
|
|
case SIGINT: |
|
pos = safecat(msg, sizeof msg, pos, "interrupt"); |
|
break; |
|
|
|
case SIGSEGV: |
|
pos = safecat(msg, sizeof msg, pos, "invalid memory access"); |
|
break; |
|
|
|
case SIGTERM: |
|
pos = safecat(msg, sizeof msg, pos, "termination request"); |
|
break; |
|
|
|
default: |
|
pos = safecat(msg, sizeof msg, pos, "unknown "); |
|
pos = safecatn(msg, sizeof msg, pos, signum); |
|
break; |
|
} |
|
|
|
store_log(&pm.this, NULL/*png_structp*/, msg, 1/*error*/); |
|
|
|
/* And finally throw an exception so we can keep going, unless this is |
|
* SIGTERM in which case stop now. |
|
*/ |
|
if (signum != SIGTERM) |
|
{ |
|
struct exception_context *the_exception_context = |
|
&pm.this.exception_context; |
|
|
|
Throw &pm.this; |
|
} |
|
|
|
else |
|
exit(1); |
|
} |
|
|
|
/* main program */ |
|
int main(int argc, char **argv) |
|
{ |
|
int summary = 1; /* Print the error summary at the end */ |
|
int memstats = 0; /* Print memory statistics at the end */ |
|
|
|
/* Create the given output file on success: */ |
|
const char *touch = NULL; |
|
|
|
/* This is an array of standard gamma values (believe it or not I've seen |
|
* every one of these mentioned somewhere.) |
|
* |
|
* In the following list the most useful values are first! |
|
*/ |
|
static double |
|
gammas[]={2.2, 1.0, 2.2/1.45, 1.8, 1.5, 2.4, 2.5, 2.62, 2.9}; |
|
|
|
/* This records the command and arguments: */ |
|
size_t cp = 0; |
|
char command[1024]; |
|
|
|
anon_context(&pm.this); |
|
|
|
gnu_volatile(summary) |
|
gnu_volatile(memstats) |
|
gnu_volatile(touch) |
|
|
|
/* Add appropriate signal handlers, just the ANSI specified ones: */ |
|
signal(SIGABRT, signal_handler); |
|
signal(SIGFPE, signal_handler); |
|
signal(SIGILL, signal_handler); |
|
signal(SIGINT, signal_handler); |
|
signal(SIGSEGV, signal_handler); |
|
signal(SIGTERM, signal_handler); |
|
|
|
#ifdef HAVE_FEENABLEEXCEPT |
|
/* Only required to enable FP exceptions on platforms where they start off |
|
* disabled; this is not necessary but if it is not done pngvalid will likely |
|
* end up ignoring FP conditions that other platforms fault. |
|
*/ |
|
feenableexcept(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW); |
|
#endif |
|
|
|
modifier_init(&pm); |
|
|
|
/* Preallocate the image buffer, because we know how big it needs to be, |
|
* note that, for testing purposes, it is deliberately mis-aligned by tag |
|
* bytes either side. All rows have an additional five bytes of padding for |
|
* overwrite checking. |
|
*/ |
|
store_ensure_image(&pm.this, NULL, 2, TRANSFORM_ROWMAX, TRANSFORM_HEIGHTMAX); |
|
|
|
/* Don't give argv[0], it's normally some horrible libtool string: */ |
|
cp = safecat(command, sizeof command, cp, "pngvalid"); |
|
|
|
/* Default to error on warning: */ |
|
pm.this.treat_warnings_as_errors = 1; |
|
|
|
/* Default assume_16_bit_calculations appropriately; this tells the checking |
|
* code that 16-bit arithmetic is used for 8-bit samples when it would make a |
|
* difference. |
|
*/ |
|
pm.assume_16_bit_calculations = PNG_LIBPNG_VER >= 10700; |
|
|
|
/* Currently 16 bit expansion happens at the end of the pipeline, so the |
|
* calculations are done in the input bit depth not the output. |
|
* |
|
* TODO: fix this |
|
*/ |
|
pm.calculations_use_input_precision = 1U; |
|
|
|
/* Store the test gammas */ |
|
pm.gammas = gammas; |
|
pm.ngammas = ARRAY_SIZE(gammas); |
|
pm.ngamma_tests = 0; /* default to off */ |
|
|
|
/* Low bit depth gray images don't do well in the gamma tests, until |
|
* this is fixed turn them off for some gamma cases: |
|
*/ |
|
# ifdef PNG_WRITE_tRNS_SUPPORTED |
|
pm.test_tRNS = 1; |
|
# endif |
|
pm.test_lbg = PNG_LIBPNG_VER >= 10600; |
|
pm.test_lbg_gamma_threshold = 1; |
|
pm.test_lbg_gamma_transform = PNG_LIBPNG_VER >= 10600; |
|
pm.test_lbg_gamma_sbit = 1; |
|
pm.test_lbg_gamma_composition = PNG_LIBPNG_VER >= 10700; |
|
|
|
/* And the test encodings */ |
|
pm.encodings = test_encodings; |
|
pm.nencodings = ARRAY_SIZE(test_encodings); |
|
|
|
# if PNG_LIBPNG_VER < 10700 |
|
pm.sbitlow = 8U; /* because libpng doesn't do sBIT below 8! */ |
|
# else |
|
pm.sbitlow = 1U; |
|
# endif |
|
|
|
/* The following allows results to pass if they correspond to anything in the |
|
* transformed range [input-.5,input+.5]; this is is required because of the |
|
* way libpng treates the 16_TO_8 flag when building the gamma tables in |
|
* releases up to 1.6.0. |
|
* |
|
* TODO: review this |
|
*/ |
|
pm.use_input_precision_16to8 = 1U; |
|
pm.use_input_precision_sbit = 1U; /* because libpng now rounds sBIT */ |
|
|
|
/* Some default values (set the behavior for 'make check' here). |
|
* These values simply control the maximum error permitted in the gamma |
|
* transformations. The practical limits for human perception are described |
|
* below (the setting for maxpc16), however for 8 bit encodings it isn't |
|
* possible to meet the accepted capabilities of human vision - i.e. 8 bit |
|
* images can never be good enough, regardless of encoding. |
|
*/ |
|
pm.maxout8 = .1; /* Arithmetic error in *encoded* value */ |
|
pm.maxabs8 = .00005; /* 1/20000 */ |
|
pm.maxcalc8 = 1./255; /* +/-1 in 8 bits for compose errors */ |
|
pm.maxpc8 = .499; /* I.e., .499% fractional error */ |
|
pm.maxout16 = .499; /* Error in *encoded* value */ |
|
pm.maxabs16 = .00005;/* 1/20000 */ |
|
pm.maxcalc16 =1./65535;/* +/-1 in 16 bits for compose errors */ |
|
# if PNG_LIBPNG_VER < 10700 |
|
pm.maxcalcG = 1./((1<<PNG_MAX_GAMMA_8)-1); |
|
# else |
|
pm.maxcalcG = 1./((1<<16)-1); |
|
# endif |
|
|
|
/* NOTE: this is a reasonable perceptual limit. We assume that humans can |
|
* perceive light level differences of 1% over a 100:1 range, so we need to |
|
* maintain 1 in 10000 accuracy (in linear light space), which is what the |
|
* following guarantees. It also allows significantly higher errors at |
|
* higher 16 bit values, which is important for performance. The actual |
|
* maximum 16 bit error is about +/-1.9 in the fixed point implementation but |
|
* this is only allowed for values >38149 by the following: |
|
*/ |
|
pm.maxpc16 = .005; /* I.e., 1/200% - 1/20000 */ |
|
|
|
/* Now parse the command line options. */ |
|
while (--argc >= 1) |
|
{ |
|
int catmore = 0; /* Set if the argument has an argument. */ |
|
|
|
/* Record each argument for posterity: */ |
|
cp = safecat(command, sizeof command, cp, " "); |
|
cp = safecat(command, sizeof command, cp, *++argv); |
|
|
|
if (strcmp(*argv, "-v") == 0) |
|
pm.this.verbose = 1; |
|
|
|
else if (strcmp(*argv, "-l") == 0) |
|
pm.log = 1; |
|
|
|
else if (strcmp(*argv, "-q") == 0) |
|
summary = pm.this.verbose = pm.log = 0; |
|
|
|
else if (strcmp(*argv, "-w") == 0 || |
|
strcmp(*argv, "--strict") == 0) |
|
pm.this.treat_warnings_as_errors = 1; /* NOTE: this is the default! */ |
|
|
|
else if (strcmp(*argv, "--nostrict") == 0) |
|
pm.this.treat_warnings_as_errors = 0; |
|
|
|
else if (strcmp(*argv, "--speed") == 0) |
|
pm.this.speed = 1, pm.ngamma_tests = pm.ngammas, pm.test_standard = 0, |
|
summary = 0; |
|
|
|
else if (strcmp(*argv, "--memory") == 0) |
|
memstats = 1; |
|
|
|
else if (strcmp(*argv, "--size") == 0) |
|
pm.test_size = 1; |
|
|
|
else if (strcmp(*argv, "--nosize") == 0) |
|
pm.test_size = 0; |
|
|
|
else if (strcmp(*argv, "--standard") == 0) |
|
pm.test_standard = 1; |
|
|
|
else if (strcmp(*argv, "--nostandard") == 0) |
|
pm.test_standard = 0; |
|
|
|
else if (strcmp(*argv, "--transform") == 0) |
|
pm.test_transform = 1; |
|
|
|
else if (strcmp(*argv, "--notransform") == 0) |
|
pm.test_transform = 0; |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
else if (strncmp(*argv, "--transform-disable=", |
|
sizeof "--transform-disable") == 0) |
|
{ |
|
pm.test_transform = 1; |
|
transform_disable(*argv + sizeof "--transform-disable"); |
|
} |
|
|
|
else if (strncmp(*argv, "--transform-enable=", |
|
sizeof "--transform-enable") == 0) |
|
{ |
|
pm.test_transform = 1; |
|
transform_enable(*argv + sizeof "--transform-enable"); |
|
} |
|
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
|
|
else if (strcmp(*argv, "--gamma") == 0) |
|
{ |
|
/* Just do two gamma tests here (2.2 and linear) for speed: */ |
|
pm.ngamma_tests = 2U; |
|
pm.test_gamma_threshold = 1; |
|
pm.test_gamma_transform = 1; |
|
pm.test_gamma_sbit = 1; |
|
pm.test_gamma_scale16 = 1; |
|
pm.test_gamma_background = 1; /* composition */ |
|
pm.test_gamma_alpha_mode = 1; |
|
} |
|
|
|
else if (strcmp(*argv, "--nogamma") == 0) |
|
pm.ngamma_tests = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-threshold") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_threshold = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-threshold") == 0) |
|
pm.test_gamma_threshold = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-transform") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_transform = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-transform") == 0) |
|
pm.test_gamma_transform = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-sbit") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_sbit = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-sbit") == 0) |
|
pm.test_gamma_sbit = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-16-to-8") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_scale16 = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-16-to-8") == 0) |
|
pm.test_gamma_scale16 = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-background") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_background = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-background") == 0) |
|
pm.test_gamma_background = 0; |
|
|
|
else if (strcmp(*argv, "--gamma-alpha-mode") == 0) |
|
pm.ngamma_tests = 2U, pm.test_gamma_alpha_mode = 1; |
|
|
|
else if (strcmp(*argv, "--nogamma-alpha-mode") == 0) |
|
pm.test_gamma_alpha_mode = 0; |
|
|
|
else if (strcmp(*argv, "--expand16") == 0) |
|
pm.test_gamma_expand16 = 1; |
|
|
|
else if (strcmp(*argv, "--noexpand16") == 0) |
|
pm.test_gamma_expand16 = 0; |
|
|
|
else if (strcmp(*argv, "--low-depth-gray") == 0) |
|
pm.test_lbg = pm.test_lbg_gamma_threshold = |
|
pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit = |
|
pm.test_lbg_gamma_composition = 1; |
|
|
|
else if (strcmp(*argv, "--nolow-depth-gray") == 0) |
|
pm.test_lbg = pm.test_lbg_gamma_threshold = |
|
pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit = |
|
pm.test_lbg_gamma_composition = 0; |
|
|
|
# ifdef PNG_WRITE_tRNS_SUPPORTED |
|
else if (strcmp(*argv, "--tRNS") == 0) |
|
pm.test_tRNS = 1; |
|
# endif |
|
|
|
else if (strcmp(*argv, "--notRNS") == 0) |
|
pm.test_tRNS = 0; |
|
|
|
else if (strcmp(*argv, "--more-gammas") == 0) |
|
pm.ngamma_tests = 3U; |
|
|
|
else if (strcmp(*argv, "--all-gammas") == 0) |
|
pm.ngamma_tests = pm.ngammas; |
|
|
|
else if (strcmp(*argv, "--progressive-read") == 0) |
|
pm.this.progressive = 1; |
|
|
|
else if (strcmp(*argv, "--use-update-info") == 0) |
|
++pm.use_update_info; /* Can call multiple times */ |
|
|
|
else if (strcmp(*argv, "--interlace") == 0) |
|
{ |
|
# if CAN_WRITE_INTERLACE |
|
pm.interlace_type = PNG_INTERLACE_ADAM7; |
|
# else /* !CAN_WRITE_INTERLACE */ |
|
fprintf(stderr, "pngvalid: no write interlace support\n"); |
|
return SKIP; |
|
# endif /* !CAN_WRITE_INTERLACE */ |
|
} |
|
|
|
else if (strcmp(*argv, "--use-input-precision") == 0) |
|
pm.use_input_precision = 1U; |
|
|
|
else if (strcmp(*argv, "--use-calculation-precision") == 0) |
|
pm.use_input_precision = 0; |
|
|
|
else if (strcmp(*argv, "--calculations-use-input-precision") == 0) |
|
pm.calculations_use_input_precision = 1U; |
|
|
|
else if (strcmp(*argv, "--assume-16-bit-calculations") == 0) |
|
pm.assume_16_bit_calculations = 1U; |
|
|
|
else if (strcmp(*argv, "--calculations-follow-bit-depth") == 0) |
|
pm.calculations_use_input_precision = |
|
pm.assume_16_bit_calculations = 0; |
|
|
|
else if (strcmp(*argv, "--exhaustive") == 0) |
|
pm.test_exhaustive = 1; |
|
|
|
else if (argc > 1 && strcmp(*argv, "--sbitlow") == 0) |
|
--argc, pm.sbitlow = (png_byte)atoi(*++argv), catmore = 1; |
|
|
|
else if (argc > 1 && strcmp(*argv, "--touch") == 0) |
|
--argc, touch = *++argv, catmore = 1; |
|
|
|
else if (argc > 1 && strncmp(*argv, "--max", 5) == 0) |
|
{ |
|
--argc; |
|
|
|
if (strcmp(5+*argv, "abs8") == 0) |
|
pm.maxabs8 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "abs16") == 0) |
|
pm.maxabs16 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "calc8") == 0) |
|
pm.maxcalc8 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "calc16") == 0) |
|
pm.maxcalc16 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "out8") == 0) |
|
pm.maxout8 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "out16") == 0) |
|
pm.maxout16 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "pc8") == 0) |
|
pm.maxpc8 = atof(*++argv); |
|
|
|
else if (strcmp(5+*argv, "pc16") == 0) |
|
pm.maxpc16 = atof(*++argv); |
|
|
|
else |
|
{ |
|
fprintf(stderr, "pngvalid: %s: unknown 'max' option\n", *argv); |
|
exit(99); |
|
} |
|
|
|
catmore = 1; |
|
} |
|
|
|
else if (strcmp(*argv, "--log8") == 0) |
|
--argc, pm.log8 = atof(*++argv), catmore = 1; |
|
|
|
else if (strcmp(*argv, "--log16") == 0) |
|
--argc, pm.log16 = atof(*++argv), catmore = 1; |
|
|
|
#ifdef PNG_SET_OPTION_SUPPORTED |
|
else if (strncmp(*argv, "--option=", 9) == 0) |
|
{ |
|
/* Syntax of the argument is <option>:{on|off} */ |
|
const char *arg = 9+*argv; |
|
unsigned char option=0, setting=0; |
|
|
|
#ifdef PNG_ARM_NEON |
|
if (strncmp(arg, "arm-neon:", 9) == 0) |
|
option = PNG_ARM_NEON, arg += 9; |
|
|
|
else |
|
#endif |
|
#ifdef PNG_EXTENSIONS |
|
if (strncmp(arg, "extensions:", 11) == 0) |
|
option = PNG_EXTENSIONS, arg += 11; |
|
|
|
else |
|
#endif |
|
#ifdef PNG_MAXIMUM_INFLATE_WINDOW |
|
if (strncmp(arg, "max-inflate-window:", 19) == 0) |
|
option = PNG_MAXIMUM_INFLATE_WINDOW, arg += 19; |
|
|
|
else |
|
#endif |
|
{ |
|
fprintf(stderr, "pngvalid: %s: %s: unknown option\n", *argv, arg); |
|
exit(99); |
|
} |
|
|
|
if (strcmp(arg, "off") == 0) |
|
setting = PNG_OPTION_OFF; |
|
|
|
else if (strcmp(arg, "on") == 0) |
|
setting = PNG_OPTION_ON; |
|
|
|
else |
|
{ |
|
fprintf(stderr, |
|
"pngvalid: %s: %s: unknown setting (use 'on' or 'off')\n", |
|
*argv, arg); |
|
exit(99); |
|
} |
|
|
|
pm.this.options[pm.this.noptions].option = option; |
|
pm.this.options[pm.this.noptions++].setting = setting; |
|
} |
|
#endif /* PNG_SET_OPTION_SUPPORTED */ |
|
|
|
else |
|
{ |
|
fprintf(stderr, "pngvalid: %s: unknown argument\n", *argv); |
|
exit(99); |
|
} |
|
|
|
if (catmore) /* consumed an extra *argv */ |
|
{ |
|
cp = safecat(command, sizeof command, cp, " "); |
|
cp = safecat(command, sizeof command, cp, *argv); |
|
} |
|
} |
|
|
|
/* If pngvalid is run with no arguments default to a reasonable set of the |
|
* tests. |
|
*/ |
|
if (pm.test_standard == 0 && pm.test_size == 0 && pm.test_transform == 0 && |
|
pm.ngamma_tests == 0) |
|
{ |
|
/* Make this do all the tests done in the test shell scripts with the same |
|
* parameters, where possible. The limitation is that all the progressive |
|
* read and interlace stuff has to be done in separate runs, so only the |
|
* basic 'standard' and 'size' tests are done. |
|
*/ |
|
pm.test_standard = 1; |
|
pm.test_size = 1; |
|
pm.test_transform = 1; |
|
pm.ngamma_tests = 2U; |
|
} |
|
|
|
if (pm.ngamma_tests > 0 && |
|
pm.test_gamma_threshold == 0 && pm.test_gamma_transform == 0 && |
|
pm.test_gamma_sbit == 0 && pm.test_gamma_scale16 == 0 && |
|
pm.test_gamma_background == 0 && pm.test_gamma_alpha_mode == 0) |
|
{ |
|
pm.test_gamma_threshold = 1; |
|
pm.test_gamma_transform = 1; |
|
pm.test_gamma_sbit = 1; |
|
pm.test_gamma_scale16 = 1; |
|
pm.test_gamma_background = 1; |
|
pm.test_gamma_alpha_mode = 1; |
|
} |
|
|
|
else if (pm.ngamma_tests == 0) |
|
{ |
|
/* Nothing to test so turn everything off: */ |
|
pm.test_gamma_threshold = 0; |
|
pm.test_gamma_transform = 0; |
|
pm.test_gamma_sbit = 0; |
|
pm.test_gamma_scale16 = 0; |
|
pm.test_gamma_background = 0; |
|
pm.test_gamma_alpha_mode = 0; |
|
} |
|
|
|
Try |
|
{ |
|
/* Make useful base images */ |
|
make_transform_images(&pm); |
|
|
|
/* Perform the standard and gamma tests. */ |
|
if (pm.test_standard) |
|
{ |
|
perform_interlace_macro_validation(); |
|
perform_formatting_test(&pm.this); |
|
# ifdef PNG_READ_SUPPORTED |
|
perform_standard_test(&pm); |
|
# endif |
|
perform_error_test(&pm); |
|
} |
|
|
|
/* Various oddly sized images: */ |
|
if (pm.test_size) |
|
{ |
|
make_size_images(&pm.this); |
|
# ifdef PNG_READ_SUPPORTED |
|
perform_size_test(&pm); |
|
# endif |
|
} |
|
|
|
#ifdef PNG_READ_TRANSFORMS_SUPPORTED |
|
/* Combinatorial transforms: */ |
|
if (pm.test_transform) |
|
perform_transform_test(&pm); |
|
#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ |
|
|
|
#ifdef PNG_READ_GAMMA_SUPPORTED |
|
if (pm.ngamma_tests > 0) |
|
perform_gamma_test(&pm, summary); |
|
#endif |
|
} |
|
|
|
Catch_anonymous |
|
{ |
|
fprintf(stderr, "pngvalid: test aborted (probably failed in cleanup)\n"); |
|
if (!pm.this.verbose) |
|
{ |
|
if (pm.this.error[0] != 0) |
|
fprintf(stderr, "pngvalid: first error: %s\n", pm.this.error); |
|
|
|
fprintf(stderr, "pngvalid: run with -v to see what happened\n"); |
|
} |
|
exit(1); |
|
} |
|
|
|
if (summary) |
|
{ |
|
printf("%s: %s (%s point arithmetic)\n", |
|
(pm.this.nerrors || (pm.this.treat_warnings_as_errors && |
|
pm.this.nwarnings)) ? "FAIL" : "PASS", |
|
command, |
|
#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || PNG_LIBPNG_VER < 10500 |
|
"floating" |
|
#else |
|
"fixed" |
|
#endif |
|
); |
|
} |
|
|
|
if (memstats) |
|
{ |
|
printf("Allocated memory statistics (in bytes):\n" |
|
"\tread %lu maximum single, %lu peak, %lu total\n" |
|
"\twrite %lu maximum single, %lu peak, %lu total\n", |
|
(unsigned long)pm.this.read_memory_pool.max_max, |
|
(unsigned long)pm.this.read_memory_pool.max_limit, |
|
(unsigned long)pm.this.read_memory_pool.max_total, |
|
(unsigned long)pm.this.write_memory_pool.max_max, |
|
(unsigned long)pm.this.write_memory_pool.max_limit, |
|
(unsigned long)pm.this.write_memory_pool.max_total); |
|
} |
|
|
|
/* Do this here to provoke memory corruption errors in memory not directly |
|
* allocated by libpng - not a complete test, but better than nothing. |
|
*/ |
|
store_delete(&pm.this); |
|
|
|
/* Error exit if there are any errors, and maybe if there are any |
|
* warnings. |
|
*/ |
|
if (pm.this.nerrors || (pm.this.treat_warnings_as_errors && |
|
pm.this.nwarnings)) |
|
{ |
|
if (!pm.this.verbose) |
|
fprintf(stderr, "pngvalid: %s\n", pm.this.error); |
|
|
|
fprintf(stderr, "pngvalid: %d errors, %d warnings\n", pm.this.nerrors, |
|
pm.this.nwarnings); |
|
|
|
exit(1); |
|
} |
|
|
|
/* Success case. */ |
|
if (touch != NULL) |
|
{ |
|
FILE *fsuccess = fopen(touch, "wt"); |
|
|
|
if (fsuccess != NULL) |
|
{ |
|
int error = 0; |
|
fprintf(fsuccess, "PNG validation succeeded\n"); |
|
fflush(fsuccess); |
|
error = ferror(fsuccess); |
|
|
|
if (fclose(fsuccess) || error) |
|
{ |
|
fprintf(stderr, "%s: write failed\n", touch); |
|
exit(1); |
|
} |
|
} |
|
|
|
else |
|
{ |
|
fprintf(stderr, "%s: open failed\n", touch); |
|
exit(1); |
|
} |
|
} |
|
|
|
/* This is required because some very minimal configurations do not use it: |
|
*/ |
|
UNUSED(fail) |
|
return 0; |
|
} |
|
#else /* write or low level APIs not supported */ |
|
int main(void) |
|
{ |
|
fprintf(stderr, |
|
"pngvalid: no low level write support in libpng, all tests skipped\n"); |
|
/* So the test is skipped: */ |
|
return SKIP; |
|
} |
|
#endif
|
|
|