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1143 lines
32 KiB
1143 lines
32 KiB
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/* pngpread.c - read a png file in push mode |
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* |
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* libpng 1.0.1 |
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* For conditions of distribution and use, see copyright notice in png.h |
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* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
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* Copyright (c) 1996, 1997 Andreas Dilger |
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* Copyright (c) 1998, Glenn Randers-Pehrson |
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* March 9, 1998 |
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*/ |
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|
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#define PNG_INTERNAL |
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#include "png.h" |
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|
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#ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
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|
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void |
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png_process_data(png_structp png_ptr, png_infop info_ptr, |
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png_bytep buffer, png_size_t buffer_size) |
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{ |
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png_push_restore_buffer(png_ptr, buffer, buffer_size); |
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|
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while (png_ptr->buffer_size) |
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{ |
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png_process_some_data(png_ptr, info_ptr); |
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} |
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} |
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|
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/* What we do with the incoming data depends on what we were previously |
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* doing before we ran out of data... |
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*/ |
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void |
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png_process_some_data(png_structp png_ptr, png_infop info_ptr) |
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{ |
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switch (png_ptr->process_mode) |
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{ |
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case PNG_READ_SIG_MODE: |
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{ |
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png_push_read_sig(png_ptr, info_ptr); |
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break; |
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} |
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case PNG_READ_CHUNK_MODE: |
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{ |
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png_push_read_chunk(png_ptr, info_ptr); |
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break; |
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} |
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case PNG_READ_IDAT_MODE: |
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{ |
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png_push_read_IDAT(png_ptr); |
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break; |
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} |
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#if defined(PNG_READ_tEXt_SUPPORTED) |
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case PNG_READ_tEXt_MODE: |
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{ |
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png_push_read_tEXt(png_ptr, info_ptr); |
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break; |
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} |
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#endif |
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#if defined(PNG_READ_zTXt_SUPPORTED) |
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case PNG_READ_zTXt_MODE: |
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{ |
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png_push_read_zTXt(png_ptr, info_ptr); |
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break; |
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} |
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#endif |
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case PNG_SKIP_MODE: |
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{ |
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png_push_crc_finish(png_ptr); |
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break; |
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} |
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default: |
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{ |
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png_ptr->buffer_size = 0; |
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break; |
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} |
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} |
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} |
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|
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/* Read any remaining signature bytes from the stream and compare them with |
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* the correct PNG signature. It is possible that this routine is called |
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* with bytes already read from the signature, whether because they have been |
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* checked by the calling application, or from multiple calls to this routine. |
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*/ |
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void |
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png_push_read_sig(png_structp png_ptr, png_infop info_ptr) |
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{ |
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png_size_t num_checked = png_ptr->sig_bytes, |
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num_to_check = 8 - num_checked; |
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|
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if (png_ptr->buffer_size < num_to_check) |
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{ |
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num_to_check = png_ptr->buffer_size; |
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} |
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png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), |
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num_to_check); |
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png_ptr->sig_bytes += num_to_check; |
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|
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if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) |
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{ |
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if (num_checked < 4 && |
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png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) |
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png_error(png_ptr, "Not a PNG file"); |
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else |
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png_error(png_ptr, "PNG file corrupted by ASCII conversion"); |
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} |
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else |
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{ |
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if (png_ptr->sig_bytes >= 8) |
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{ |
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png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
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} |
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} |
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} |
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|
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void |
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png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) |
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{ |
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/* First we make sure we have enough data for the 4 byte chunk name |
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* and the 4 byte chunk length before proceeding with decoding the |
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* chunk data. To fully decode each of these chunks, we also make |
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* sure we have enough data in the buffer for the 4 byte CRC at the |
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* end of every chunk (except IDAT, which is handled separately). |
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*/ |
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if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) |
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{ |
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png_byte chunk_length[4]; |
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|
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if (png_ptr->buffer_size < 8) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_push_fill_buffer(png_ptr, chunk_length, 4); |
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png_ptr->push_length = png_get_uint_32(chunk_length); |
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png_reset_crc(png_ptr); |
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png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
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png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; |
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} |
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|
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if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
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{ |
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/* If we reach an IDAT chunk, this means we have read all of the |
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* header chunks, and we can start reading the image (or if this |
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* is called after the image has been read - we have an error). |
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*/ |
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if (png_ptr->mode & PNG_HAVE_IDAT) |
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{ |
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if (png_ptr->push_length == 0) |
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return; |
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|
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if (png_ptr->mode & PNG_AFTER_IDAT) |
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png_error(png_ptr, "Too many IDAT's found"); |
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} |
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png_ptr->idat_size = png_ptr->push_length; |
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png_ptr->mode |= PNG_HAVE_IDAT; |
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png_ptr->process_mode = PNG_READ_IDAT_MODE; |
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png_push_have_info(png_ptr, info_ptr); |
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png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; |
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png_ptr->zstream.next_out = png_ptr->row_buf; |
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return; |
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} |
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else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); |
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png_ptr->process_mode = PNG_READ_DONE_MODE; |
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png_push_have_end(png_ptr, info_ptr); |
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} |
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#if defined(PNG_READ_gAMA_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_sBIT_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_cHRM_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_sRGB_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_tRNS_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_bKGD_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_hIST_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_pHYs_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_oFFs_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_pCAL_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_tIME_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) |
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{ |
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if (png_ptr->push_length + 4 > png_ptr->buffer_size) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_tEXt_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) |
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{ |
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png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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#if defined(PNG_READ_zTXt_SUPPORTED) |
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else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) |
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{ |
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png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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#endif |
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else |
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{ |
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png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
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} |
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|
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png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; |
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} |
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|
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void |
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png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) |
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{ |
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png_ptr->process_mode = PNG_SKIP_MODE; |
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png_ptr->skip_length = skip; |
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} |
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|
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void |
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png_push_crc_finish(png_structp png_ptr) |
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{ |
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if (png_ptr->skip_length && png_ptr->save_buffer_size) |
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{ |
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png_size_t save_size; |
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|
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if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size) |
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save_size = (png_size_t)png_ptr->skip_length; |
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else |
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save_size = png_ptr->save_buffer_size; |
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|
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png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
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|
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png_ptr->skip_length -= save_size; |
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png_ptr->buffer_size -= save_size; |
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png_ptr->save_buffer_size -= save_size; |
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png_ptr->save_buffer_ptr += save_size; |
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} |
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if (png_ptr->skip_length && png_ptr->current_buffer_size) |
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{ |
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png_size_t save_size; |
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|
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if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size) |
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save_size = (png_size_t)png_ptr->skip_length; |
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else |
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save_size = png_ptr->current_buffer_size; |
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|
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png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
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|
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png_ptr->skip_length -= save_size; |
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png_ptr->buffer_size -= save_size; |
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png_ptr->current_buffer_size -= save_size; |
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png_ptr->current_buffer_ptr += save_size; |
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} |
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if (!png_ptr->skip_length) |
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{ |
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if (png_ptr->buffer_size < 4) |
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{ |
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png_push_save_buffer(png_ptr); |
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return; |
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} |
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|
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png_crc_finish(png_ptr, 0); |
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png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
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} |
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} |
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|
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void |
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png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) |
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{ |
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png_bytep ptr; |
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|
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ptr = buffer; |
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if (png_ptr->save_buffer_size) |
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{ |
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png_size_t save_size; |
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|
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if (length < png_ptr->save_buffer_size) |
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save_size = length; |
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else |
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save_size = png_ptr->save_buffer_size; |
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|
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png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); |
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length -= save_size; |
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ptr += save_size; |
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png_ptr->buffer_size -= save_size; |
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png_ptr->save_buffer_size -= save_size; |
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png_ptr->save_buffer_ptr += save_size; |
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} |
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if (length && png_ptr->current_buffer_size) |
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{ |
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png_size_t save_size; |
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|
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if (length < png_ptr->current_buffer_size) |
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save_size = length; |
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else |
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save_size = png_ptr->current_buffer_size; |
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|
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png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); |
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png_ptr->buffer_size -= save_size; |
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png_ptr->current_buffer_size -= save_size; |
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png_ptr->current_buffer_ptr += save_size; |
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} |
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} |
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|
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void |
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png_push_save_buffer(png_structp png_ptr) |
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{ |
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if (png_ptr->save_buffer_size) |
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{ |
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if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) |
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{ |
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png_size_t i; |
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png_bytep sp; |
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png_bytep dp; |
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|
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for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; |
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i < png_ptr->save_buffer_size; |
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i++, sp++, dp++) |
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{ |
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*dp = *sp; |
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} |
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} |
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} |
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if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > |
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png_ptr->save_buffer_max) |
|
{ |
|
png_size_t new_max; |
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png_bytep old_buffer; |
|
|
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new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; |
|
old_buffer = png_ptr->save_buffer; |
|
png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, |
|
(png_uint_32)new_max); |
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png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); |
|
png_free(png_ptr, old_buffer); |
|
png_ptr->save_buffer_max = new_max; |
|
} |
|
if (png_ptr->current_buffer_size) |
|
{ |
|
png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, |
|
png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); |
|
png_ptr->save_buffer_size += png_ptr->current_buffer_size; |
|
png_ptr->current_buffer_size = 0; |
|
} |
|
png_ptr->save_buffer_ptr = png_ptr->save_buffer; |
|
png_ptr->buffer_size = 0; |
|
} |
|
|
|
void |
|
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, |
|
png_size_t buffer_length) |
|
{ |
|
png_ptr->current_buffer = buffer; |
|
png_ptr->current_buffer_size = buffer_length; |
|
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; |
|
png_ptr->current_buffer_ptr = png_ptr->current_buffer; |
|
} |
|
|
|
void |
|
png_push_read_IDAT(png_structp png_ptr) |
|
{ |
|
if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) |
|
{ |
|
png_byte chunk_length[4]; |
|
|
|
if (png_ptr->buffer_size < 8) |
|
{ |
|
png_push_save_buffer(png_ptr); |
|
return; |
|
} |
|
|
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png_push_fill_buffer(png_ptr, chunk_length, 4); |
|
png_ptr->push_length = png_get_uint_32(chunk_length); |
|
|
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png_reset_crc(png_ptr); |
|
png_crc_read(png_ptr, png_ptr->chunk_name, 4); |
|
png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; |
|
|
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if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
|
{ |
|
png_ptr->process_mode = PNG_READ_CHUNK_MODE; |
|
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) |
|
png_error(png_ptr, "Not enough compressed data"); |
|
return; |
|
} |
|
|
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png_ptr->idat_size = png_ptr->push_length; |
|
} |
|
if (png_ptr->idat_size && png_ptr->save_buffer_size) |
|
{ |
|
png_size_t save_size; |
|
|
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if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size) |
|
{ |
|
save_size = (png_size_t)png_ptr->idat_size; |
|
/* check for overflow */ |
|
if((png_uint_32)save_size != png_ptr->idat_size) |
|
png_error(png_ptr, "save_size overflowed in pngpread"); |
|
} |
|
else |
|
save_size = png_ptr->save_buffer_size; |
|
|
|
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
|
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); |
|
|
|
png_ptr->idat_size -= save_size; |
|
png_ptr->buffer_size -= save_size; |
|
png_ptr->save_buffer_size -= save_size; |
|
png_ptr->save_buffer_ptr += save_size; |
|
} |
|
if (png_ptr->idat_size && png_ptr->current_buffer_size) |
|
{ |
|
png_size_t save_size; |
|
|
|
if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size) |
|
{ |
|
save_size = (png_size_t)png_ptr->idat_size; |
|
/* check for overflow */ |
|
if((png_uint_32)save_size != png_ptr->idat_size) |
|
png_error(png_ptr, "save_size overflowed in pngpread"); |
|
} |
|
else |
|
save_size = png_ptr->current_buffer_size; |
|
|
|
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
|
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); |
|
|
|
png_ptr->idat_size -= save_size; |
|
png_ptr->buffer_size -= save_size; |
|
png_ptr->current_buffer_size -= save_size; |
|
png_ptr->current_buffer_ptr += save_size; |
|
} |
|
if (!png_ptr->idat_size) |
|
{ |
|
if (png_ptr->buffer_size < 4) |
|
{ |
|
png_push_save_buffer(png_ptr); |
|
return; |
|
} |
|
|
|
png_crc_finish(png_ptr, 0); |
|
png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; |
|
} |
|
} |
|
|
|
void |
|
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, |
|
png_size_t buffer_length) |
|
{ |
|
int ret; |
|
|
|
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length) |
|
png_error(png_ptr, "Extra compression data"); |
|
|
|
png_ptr->zstream.next_in = buffer; |
|
png_ptr->zstream.avail_in = (uInt)buffer_length; |
|
for(;;) |
|
{ |
|
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
|
if (ret == Z_STREAM_END) |
|
{ |
|
if (png_ptr->zstream.avail_in) |
|
png_error(png_ptr, "Extra compressed data"); |
|
if (!(png_ptr->zstream.avail_out)) |
|
{ |
|
png_push_process_row(png_ptr); |
|
} |
|
|
|
png_ptr->mode |= PNG_AFTER_IDAT; |
|
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
|
break; |
|
} |
|
else if (ret == Z_BUF_ERROR) |
|
break; |
|
else if (ret != Z_OK) |
|
png_error(png_ptr, "Decompression Error"); |
|
if (!(png_ptr->zstream.avail_out)) |
|
{ |
|
png_push_process_row(png_ptr); |
|
png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; |
|
png_ptr->zstream.next_out = png_ptr->row_buf; |
|
} |
|
else |
|
break; |
|
} |
|
} |
|
|
|
void |
|
png_push_process_row(png_structp png_ptr) |
|
{ |
|
png_ptr->row_info.color_type = png_ptr->color_type; |
|
png_ptr->row_info.width = png_ptr->iwidth; |
|
png_ptr->row_info.channels = png_ptr->channels; |
|
png_ptr->row_info.bit_depth = png_ptr->bit_depth; |
|
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; |
|
|
|
png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * |
|
(png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); |
|
|
|
png_read_filter_row(png_ptr, &(png_ptr->row_info), |
|
png_ptr->row_buf + 1, png_ptr->prev_row + 1, |
|
(int)(png_ptr->row_buf[0])); |
|
|
|
png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, |
|
png_ptr->rowbytes + 1); |
|
|
|
if (png_ptr->transformations) |
|
png_do_read_transformations(png_ptr); |
|
|
|
#if defined(PNG_READ_INTERLACING_SUPPORTED) |
|
/* blow up interlaced rows to full size */ |
|
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) |
|
{ |
|
if (png_ptr->pass < 6) |
|
png_do_read_interlace(&(png_ptr->row_info), |
|
png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); |
|
|
|
switch (png_ptr->pass) |
|
{ |
|
case 0: |
|
{ |
|
int i; |
|
for (i = 0; i < 8 && png_ptr->pass == 0; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
break; |
|
} |
|
case 1: |
|
{ |
|
int i; |
|
for (i = 0; i < 8 && png_ptr->pass == 1; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
if (png_ptr->pass == 2) |
|
{ |
|
for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
{ |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
} |
|
break; |
|
} |
|
case 2: |
|
{ |
|
int i; |
|
for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
|
{ |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
break; |
|
} |
|
case 3: |
|
{ |
|
int i; |
|
for (i = 0; i < 4 && png_ptr->pass == 3; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
if (png_ptr->pass == 4) |
|
{ |
|
for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
{ |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
} |
|
break; |
|
} |
|
case 4: |
|
{ |
|
int i; |
|
for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
|
{ |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
break; |
|
} |
|
case 5: |
|
{ |
|
int i; |
|
for (i = 0; i < 2 && png_ptr->pass == 5; i++) |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
if (png_ptr->pass == 6) |
|
{ |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
break; |
|
} |
|
case 6: |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
if (png_ptr->pass != 6) |
|
break; |
|
png_push_have_row(png_ptr, NULL); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
} |
|
} |
|
else |
|
#endif |
|
{ |
|
png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
|
png_read_push_finish_row(png_ptr); |
|
} |
|
} |
|
|
|
void |
|
png_read_push_finish_row(png_structp png_ptr) |
|
{ |
|
png_ptr->row_number++; |
|
if (png_ptr->row_number < png_ptr->num_rows) |
|
return; |
|
|
|
if (png_ptr->interlaced) |
|
{ |
|
png_ptr->row_number = 0; |
|
png_memset_check(png_ptr, png_ptr->prev_row, 0, |
|
png_ptr->rowbytes + 1); |
|
do |
|
{ |
|
png_ptr->pass++; |
|
if (png_ptr->pass >= 7) |
|
break; |
|
png_ptr->iwidth = (png_ptr->width + |
|
png_pass_inc[png_ptr->pass] - 1 - |
|
png_pass_start[png_ptr->pass]) / |
|
png_pass_inc[png_ptr->pass]; |
|
|
|
png_ptr->irowbytes = ((png_ptr->iwidth * |
|
png_ptr->pixel_depth + 7) >> 3) + 1; |
|
|
|
if (!(png_ptr->transformations & PNG_INTERLACE)) |
|
{ |
|
png_ptr->num_rows = (png_ptr->height + |
|
png_pass_yinc[png_ptr->pass] - 1 - |
|
png_pass_ystart[png_ptr->pass]) / |
|
png_pass_yinc[png_ptr->pass]; |
|
if (!(png_ptr->num_rows)) |
|
continue; |
|
} |
|
if (png_ptr->transformations & PNG_INTERLACE) |
|
break; |
|
} while (png_ptr->iwidth == 0); |
|
} |
|
} |
|
|
|
#if defined(PNG_READ_tEXt_SUPPORTED) |
|
void |
|
png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) |
|
{ |
|
png_error(png_ptr, "Out of place tEXt"); |
|
/* to quiet some compiler warnings */ |
|
if(info_ptr == NULL) return; |
|
} |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
png_ptr->skip_length = 0; /* This may not be necessary */ |
|
|
|
if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */ |
|
{ |
|
png_warning(png_ptr, "tEXt chunk too large to fit in memory"); |
|
png_ptr->skip_length = length - (png_uint_32)65535L; |
|
length = (png_uint_32)65535L; |
|
} |
|
#endif |
|
|
|
png_ptr->current_text = (png_charp)png_malloc(png_ptr, |
|
(png_uint_32)(length+1)); |
|
png_ptr->current_text[length] = '\0'; |
|
png_ptr->current_text_ptr = png_ptr->current_text; |
|
png_ptr->current_text_size = (png_size_t)length; |
|
png_ptr->current_text_left = (png_size_t)length; |
|
png_ptr->process_mode = PNG_READ_tEXt_MODE; |
|
} |
|
|
|
void |
|
png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) |
|
{ |
|
if (png_ptr->buffer_size && png_ptr->current_text_left) |
|
{ |
|
png_size_t text_size; |
|
|
|
if (png_ptr->buffer_size < png_ptr->current_text_left) |
|
text_size = png_ptr->buffer_size; |
|
else |
|
text_size = png_ptr->current_text_left; |
|
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); |
|
png_ptr->current_text_left -= text_size; |
|
png_ptr->current_text_ptr += text_size; |
|
} |
|
if (!(png_ptr->current_text_left)) |
|
{ |
|
png_textp text_ptr; |
|
png_charp text; |
|
png_charp key; |
|
|
|
if (png_ptr->buffer_size < 4) |
|
{ |
|
png_push_save_buffer(png_ptr); |
|
return; |
|
} |
|
|
|
png_push_crc_finish(png_ptr); |
|
|
|
#if defined(PNG_MAX_MALLOC_64K) |
|
if (png_ptr->skip_length) |
|
return; |
|
#endif |
|
|
|
key = png_ptr->current_text; |
|
png_ptr->current_text = 0; |
|
|
|
for (text = key; *text; text++) |
|
/* empty loop */ ; |
|
|
|
if (text != key + png_ptr->current_text_size) |
|
text++; |
|
|
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
|
text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
|
text_ptr->key = key; |
|
text_ptr->text = text; |
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1); |
|
|
|
png_free(png_ptr, text_ptr); |
|
} |
|
} |
|
#endif |
|
|
|
#if defined(PNG_READ_zTXt_SUPPORTED) |
|
void |
|
png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) |
|
{ |
|
png_error(png_ptr, "Out of place zTXt"); |
|
/* to quiet some compiler warnings */ |
|
if(info_ptr == NULL) return; |
|
} |
|
|
|
#ifdef PNG_MAX_MALLOC_64K |
|
/* We can't handle zTXt chunks > 64K, since we don't have enough space |
|
* to be able to store the uncompressed data. Actually, the threshold |
|
* is probably around 32K, but it isn't as definite as 64K is. |
|
*/ |
|
if (length > (png_uint_32)65535L) |
|
{ |
|
png_warning(png_ptr, "zTXt chunk too large to fit in memory"); |
|
png_push_crc_skip(png_ptr, length); |
|
return; |
|
} |
|
#endif |
|
|
|
png_ptr->current_text = (png_charp)png_malloc(png_ptr, |
|
(png_uint_32)(length+1)); |
|
png_ptr->current_text[length] = '\0'; |
|
png_ptr->current_text_ptr = png_ptr->current_text; |
|
png_ptr->current_text_size = (png_size_t)length; |
|
png_ptr->current_text_left = (png_size_t)length; |
|
png_ptr->process_mode = PNG_READ_zTXt_MODE; |
|
} |
|
|
|
void |
|
png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) |
|
{ |
|
if (png_ptr->buffer_size && png_ptr->current_text_left) |
|
{ |
|
png_size_t text_size; |
|
|
|
if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) |
|
text_size = png_ptr->buffer_size; |
|
else |
|
text_size = png_ptr->current_text_left; |
|
png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); |
|
png_ptr->current_text_left -= text_size; |
|
png_ptr->current_text_ptr += text_size; |
|
} |
|
if (!(png_ptr->current_text_left)) |
|
{ |
|
png_textp text_ptr; |
|
png_charp text; |
|
png_charp key; |
|
int ret; |
|
png_size_t text_size, key_size; |
|
|
|
if (png_ptr->buffer_size < 4) |
|
{ |
|
png_push_save_buffer(png_ptr); |
|
return; |
|
} |
|
|
|
png_push_crc_finish(png_ptr); |
|
|
|
key = png_ptr->current_text; |
|
png_ptr->current_text = 0; |
|
|
|
for (text = key; *text; text++) |
|
/* empty loop */ ; |
|
|
|
/* zTXt can't have zero text */ |
|
if (text == key + png_ptr->current_text_size) |
|
{ |
|
png_free(png_ptr, key); |
|
return; |
|
} |
|
|
|
text++; |
|
|
|
if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ |
|
{ |
|
png_free(png_ptr, key); |
|
return; |
|
} |
|
|
|
text++; |
|
|
|
png_ptr->zstream.next_in = (png_bytep )text; |
|
png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - |
|
(text - key)); |
|
png_ptr->zstream.next_out = png_ptr->zbuf; |
|
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
|
|
|
key_size = text - key; |
|
text_size = 0; |
|
text = NULL; |
|
ret = Z_STREAM_END; |
|
|
|
while (png_ptr->zstream.avail_in) |
|
{ |
|
ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
|
if (ret != Z_OK && ret != Z_STREAM_END) |
|
{ |
|
inflateReset(&png_ptr->zstream); |
|
png_ptr->zstream.avail_in = 0; |
|
png_free(png_ptr, key); |
|
png_free(png_ptr, text); |
|
return; |
|
} |
|
if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) |
|
{ |
|
if (text == NULL) |
|
{ |
|
text = (png_charp)png_malloc(png_ptr, |
|
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out + |
|
key_size + 1)); |
|
png_memcpy(text + key_size, png_ptr->zbuf, |
|
png_ptr->zbuf_size - png_ptr->zstream.avail_out); |
|
png_memcpy(text, key, key_size); |
|
text_size = key_size + png_ptr->zbuf_size - |
|
png_ptr->zstream.avail_out; |
|
*(text + text_size) = '\0'; |
|
} |
|
else |
|
{ |
|
png_charp tmp; |
|
|
|
tmp = text; |
|
text = (png_charp)png_malloc(png_ptr, text_size + |
|
(png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out |
|
+ 1)); |
|
png_memcpy(text, tmp, text_size); |
|
png_free(png_ptr, tmp); |
|
png_memcpy(text + text_size, png_ptr->zbuf, |
|
png_ptr->zbuf_size - png_ptr->zstream.avail_out); |
|
text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; |
|
*(text + text_size) = '\0'; |
|
} |
|
if (ret != Z_STREAM_END) |
|
{ |
|
png_ptr->zstream.next_out = png_ptr->zbuf; |
|
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
|
} |
|
} |
|
else |
|
{ |
|
break; |
|
} |
|
|
|
if (ret == Z_STREAM_END) |
|
break; |
|
} |
|
|
|
inflateReset(&png_ptr->zstream); |
|
png_ptr->zstream.avail_in = 0; |
|
|
|
if (ret != Z_STREAM_END) |
|
{ |
|
png_free(png_ptr, key); |
|
png_free(png_ptr, text); |
|
return; |
|
} |
|
|
|
png_free(png_ptr, key); |
|
key = text; |
|
text += key_size; |
|
|
|
text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); |
|
text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; |
|
text_ptr->key = key; |
|
text_ptr->text = text; |
|
|
|
png_set_text(png_ptr, info_ptr, text_ptr, 1); |
|
|
|
png_free(png_ptr, text_ptr); |
|
} |
|
} |
|
#endif |
|
|
|
/* This function is called when we haven't found a handler for this |
|
* chunk. In the future we will have code here which can handle |
|
* user-defined callback functions for unknown chunks before they are |
|
* ignored or cause an error. If there isn't a problem with the |
|
* chunk itself (ie a bad chunk name or a critical chunk), the chunk |
|
* is (currently) silently ignored. |
|
*/ |
|
void |
|
png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
|
{ |
|
png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
|
|
|
if (!(png_ptr->chunk_name[0] & 0x20)) |
|
{ |
|
png_chunk_error(png_ptr, "unknown critical chunk"); |
|
/* to quiet some compiler warnings */ |
|
if(info_ptr == NULL) return; |
|
} |
|
|
|
png_push_crc_skip(png_ptr, length); |
|
} |
|
|
|
void |
|
png_push_have_info(png_structp png_ptr, png_infop info_ptr) |
|
{ |
|
if (png_ptr->info_fn != NULL) |
|
(*(png_ptr->info_fn))(png_ptr, info_ptr); |
|
} |
|
|
|
void |
|
png_push_have_end(png_structp png_ptr, png_infop info_ptr) |
|
{ |
|
if (png_ptr->end_fn != NULL) |
|
(*(png_ptr->end_fn))(png_ptr, info_ptr); |
|
} |
|
|
|
void |
|
png_push_have_row(png_structp png_ptr, png_bytep row) |
|
{ |
|
if (png_ptr->row_fn != NULL) |
|
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, |
|
(int)png_ptr->pass); |
|
} |
|
|
|
void |
|
png_progressive_combine_row (png_structp png_ptr, |
|
png_bytep old_row, png_bytep new_row) |
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{ |
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if (new_row != NULL) |
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png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); |
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} |
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void |
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png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, |
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png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, |
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png_progressive_end_ptr end_fn) |
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{ |
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png_ptr->info_fn = info_fn; |
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png_ptr->row_fn = row_fn; |
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png_ptr->end_fn = end_fn; |
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|
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png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); |
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} |
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png_voidp |
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png_get_progressive_ptr(png_structp png_ptr) |
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{ |
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return png_ptr->io_ptr; |
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} |
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#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |
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