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.
84 lines
2.8 KiB
84 lines
2.8 KiB
/* |
|
* jcinit.c |
|
* |
|
* Copyright (C) 1991-1997, Thomas G. Lane. |
|
* Modified 2003-2013 by Guido Vollbeding. |
|
* This file is part of the Independent JPEG Group's software. |
|
* For conditions of distribution and use, see the accompanying README file. |
|
* |
|
* This file contains initialization logic for the JPEG compressor. |
|
* This routine is in charge of selecting the modules to be executed and |
|
* making an initialization call to each one. |
|
* |
|
* Logically, this code belongs in jcmaster.c. It's split out because |
|
* linking this routine implies linking the entire compression library. |
|
* For a transcoding-only application, we want to be able to use jcmaster.c |
|
* without linking in the whole library. |
|
*/ |
|
|
|
#define JPEG_INTERNALS |
|
#include "jinclude.h" |
|
#include "jpeglib.h" |
|
|
|
|
|
/* |
|
* Master selection of compression modules. |
|
* This is done once at the start of processing an image. We determine |
|
* which modules will be used and give them appropriate initialization calls. |
|
*/ |
|
|
|
GLOBAL(void) |
|
jinit_compress_master (j_compress_ptr cinfo) |
|
{ |
|
long samplesperrow; |
|
JDIMENSION jd_samplesperrow; |
|
|
|
/* For now, precision must match compiled-in value... */ |
|
if (cinfo->data_precision != BITS_IN_JSAMPLE) |
|
ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); |
|
|
|
/* Sanity check on image dimensions */ |
|
if (cinfo->image_height <= 0 || cinfo->image_width <= 0 || |
|
cinfo->input_components <= 0) |
|
ERREXIT(cinfo, JERR_EMPTY_IMAGE); |
|
|
|
/* Width of an input scanline must be representable as JDIMENSION. */ |
|
samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components; |
|
jd_samplesperrow = (JDIMENSION) samplesperrow; |
|
if ((long) jd_samplesperrow != samplesperrow) |
|
ERREXIT(cinfo, JERR_WIDTH_OVERFLOW); |
|
|
|
/* Initialize master control (includes parameter checking/processing) */ |
|
jinit_c_master_control(cinfo, FALSE /* full compression */); |
|
|
|
/* Preprocessing */ |
|
if (! cinfo->raw_data_in) { |
|
jinit_color_converter(cinfo); |
|
jinit_downsampler(cinfo); |
|
jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */); |
|
} |
|
/* Forward DCT */ |
|
jinit_forward_dct(cinfo); |
|
/* Entropy encoding: either Huffman or arithmetic coding. */ |
|
if (cinfo->arith_code) |
|
jinit_arith_encoder(cinfo); |
|
else { |
|
jinit_huff_encoder(cinfo); |
|
} |
|
|
|
/* Need a full-image coefficient buffer in any multi-pass mode. */ |
|
jinit_c_coef_controller(cinfo, |
|
(boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding)); |
|
jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */); |
|
|
|
jinit_marker_writer(cinfo); |
|
|
|
/* We can now tell the memory manager to allocate virtual arrays. */ |
|
(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo); |
|
|
|
/* Write the datastream header (SOI) immediately. |
|
* Frame and scan headers are postponed till later. |
|
* This lets application insert special markers after the SOI. |
|
*/ |
|
(*cinfo->marker->write_file_header) (cinfo); |
|
}
|
|
|