📄 libmng_chunk_io.c
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/** ************************************************************************* */
/* * For conditions of distribution and use, * */
/* * see copyright notice in libmng.h * */
/* ************************************************************************** */
/* * * */
/* * project : libmng * */
/* * file : libmng_chunk_io.c copyright (c) 2000-2004 G.Juyn * */
/* * version : 1.0.8 * */
/* * * */
/* * purpose : Chunk I/O routines (implementation) * */
/* * * */
/* * author : G.Juyn * */
/* * * */
/* * comment : implementation of chunk input/output routines * */
/* * * */
/* * changes : 0.5.1 - 05/01/2000 - G.Juyn * */
/* * - cleaned up left-over teststuff in the BACK chunk routine * */
/* * 0.5.1 - 05/04/2000 - G.Juyn * */
/* * - changed CRC initialization to use dynamic structure * */
/* * (wasn't thread-safe the old way !) * */
/* * 0.5.1 - 05/06/2000 - G.Juyn * */
/* * - filled in many missing sequence&length checks * */
/* * - filled in many missing chunk-store snippets * */
/* * 0.5.1 - 05/08/2000 - G.Juyn * */
/* * - added checks for running animations * */
/* * - filled some write routines * */
/* * - changed strict-ANSI stuff * */
/* * 0.5.1 - 05/10/2000 - G.Juyn * */
/* * - filled some more write routines * */
/* * 0.5.1 - 05/11/2000 - G.Juyn * */
/* * - filled remaining write routines * */
/* * - fixed read_pplt with regard to deltatype * */
/* * - added callback error-reporting support * */
/* * - added pre-draft48 support (short MHDR, frame_mode, LOOP) * */
/* * 0.5.1 - 05/12/2000 - G.Juyn * */
/* * - changed trace to macro for callback error-reporting * */
/* * - fixed chunk-storage bit in several routines * */
/* * 0.5.1 - 05/13/2000 - G.Juyn * */
/* * - added eMNGma hack (will be removed in 1.0.0 !!!) * */
/* * - added TERM animation object pointer (easier reference) * */
/* * - supplemented the SAVE & SEEK display processing * */
/* * * */
/* * 0.5.2 - 05/18/2000 - G.Juyn * */
/* * - B004 - fixed problem with MNG_SUPPORT_WRITE not defined * */
/* * also for MNG_SUPPORT_WRITE without MNG_INCLUDE_JNG * */
/* * 0.5.2 - 05/19/2000 - G.Juyn * */
/* * - cleaned up some code regarding mixed support * */
/* * 0.5.2 - 05/20/2000 - G.Juyn * */
/* * - implemented JNG support * */
/* * 0.5.2 - 05/24/2000 - G.Juyn * */
/* * - added support for global color-chunks in animation * */
/* * - added support for global PLTE,tRNS,bKGD in animation * */
/* * - added support for SAVE & SEEK in animation * */
/* * 0.5.2 - 05/29/2000 - G.Juyn * */
/* * - changed ani_create calls not returning object pointer * */
/* * - create ani objects always (not just inside TERM/LOOP) * */
/* * 0.5.2 - 05/30/2000 - G.Juyn * */
/* * - added support for delta-image processing * */
/* * 0.5.2 - 05/31/2000 - G.Juyn * */
/* * - fixed up punctuation (contributed by Tim Rowley) * */
/* * 0.5.2 - 06/02/2000 - G.Juyn * */
/* * - changed SWAP_ENDIAN to BIGENDIAN_SUPPORTED * */
/* * 0.5.2 - 06/03/2000 - G.Juyn * */
/* * - fixed makeup for Linux gcc compile * */
/* * * */
/* * 0.5.3 - 06/12/2000 - G.Juyn * */
/* * - added processing of color-info on delta-image * */
/* * 0.5.3 - 06/13/2000 - G.Juyn * */
/* * - fixed handling of empty SAVE chunk * */
/* * 0.5.3 - 06/17/2000 - G.Juyn * */
/* * - changed to support delta-images * */
/* * - added extra checks for delta-images * */
/* * 0.5.3 - 06/20/2000 - G.Juyn * */
/* * - fixed possible trouble if IEND display-process got * */
/* * broken up * */
/* * 0.5.3 - 06/21/2000 - G.Juyn * */
/* * - added processing of PLTE & tRNS for delta-images * */
/* * - added administration of imagelevel parameter * */
/* * 0.5.3 - 06/22/2000 - G.Juyn * */
/* * - implemented support for PPLT chunk * */
/* * 0.5.3 - 06/26/2000 - G.Juyn * */
/* * - added precaution against faulty iCCP chunks from PS * */
/* * 0.5.3 - 06/29/2000 - G.Juyn * */
/* * - fixed some 64-bit warnings * */
/* * * */
/* * 0.9.1 - 07/14/2000 - G.Juyn * */
/* * - changed pre-draft48 frame_mode=3 to frame_mode=1 * */
/* * 0.9.1 - 07/16/2000 - G.Juyn * */
/* * - fixed storage of images during mng_read() * */
/* * - fixed support for mng_display() after mng_read() * */
/* * 0.9.1 - 07/19/2000 - G.Juyn * */
/* * - fixed several chunk-writing routines * */
/* * 0.9.1 - 07/24/2000 - G.Juyn * */
/* * - fixed reading of still-images * */
/* * * */
/* * 0.9.2 - 08/05/2000 - G.Juyn * */
/* * - changed file-prefixes * */
/* * * */
/* * 0.9.3 - 08/07/2000 - G.Juyn * */
/* * - B111300 - fixup for improved portability * */
/* * 0.9.3 - 08/08/2000 - G.Juyn * */
/* * - fixed compiler-warnings from Mozilla * */
/* * 0.9.3 - 08/09/2000 - G.Juyn * */
/* * - added check for simplicity-bits in MHDR * */
/* * 0.9.3 - 08/12/2000 - G.Juyn * */
/* * - fixed check for simplicity-bits in MHDR (JNG) * */
/* * 0.9.3 - 08/12/2000 - G.Juyn * */
/* * - added workaround for faulty PhotoShop iCCP chunk * */
/* * 0.9.3 - 08/22/2000 - G.Juyn * */
/* * - fixed write-code for zTXt & iTXt * */
/* * - fixed read-code for iTXt * */
/* * 0.9.3 - 08/26/2000 - G.Juyn * */
/* * - added MAGN chunk * */
/* * 0.9.3 - 09/07/2000 - G.Juyn * */
/* * - added support for new filter_types * */
/* * 0.9.3 - 09/10/2000 - G.Juyn * */
/* * - fixed DEFI behavior * */
/* * 0.9.3 - 10/02/2000 - G.Juyn * */
/* * - fixed simplicity-check in compliance with draft 81/0.98a * */
/* * 0.9.3 - 10/10/2000 - G.Juyn * */
/* * - added support for alpha-depth prediction * */
/* * 0.9.3 - 10/11/2000 - G.Juyn * */
/* * - added support for nEED * */
/* * 0.9.3 - 10/16/2000 - G.Juyn * */
/* * - added support for JDAA * */
/* * 0.9.3 - 10/17/2000 - G.Juyn * */
/* * - fixed support for MAGN * */
/* * - implemented nEED "xxxx" (where "xxxx" is a chunkid) * */
/* * - added callback to process non-critical unknown chunks * */
/* * - fixed support for bKGD * */
/* * 0.9.3 - 10/23/2000 - G.Juyn * */
/* * - fixed bug in empty PLTE handling * */
/* * * */
/* * 0.9.4 - 11/20/2000 - G.Juyn * */
/* * - changed IHDR filter_method check for PNGs * */
/* * 0.9.4 - 1/18/2001 - G.Juyn * */
/* * - added errorchecking for MAGN methods * */
/* * - removed test filter-methods 1 & 65 * */
/* * * */
/* * 0.9.5 - 1/25/2001 - G.Juyn * */
/* * - fixed some small compiler warnings (thanks Nikki) * */
/* * * */
/* * 1.0.2 - 05/05/2000 - G.Juyn * */
/* * - B421427 - writes wrong format in bKGD and tRNS * */
/* * 1.0.2 - 06/20/2000 - G.Juyn * */
/* * - B434583 - compiler-warning if MNG_STORE_CHUNKS undefined * */
/* * * */
/* * 1.0.5 - 07/08/2002 - G.Juyn * */
/* * - B578572 - removed eMNGma hack (thanks Dimitri!) * */
/* * 1.0.5 - 08/07/2002 - G.Juyn * */
/* * - added test-option for PNG filter method 193 (=no filter) * */
/* * 1.0.5 - 08/15/2002 - G.Juyn * */
/* * - completed PROM support * */
/* * 1.0.5 - 08/19/2002 - G.Juyn * */
/* * - B597134 - libmng pollutes the linker namespace * */
/* * 1.0.5 - 09/07/2002 - G.Juyn * */
/* * - fixed reading of FRAM with just frame_mode and name * */
/* * 1.0.5 - 09/13/2002 - G.Juyn * */
/* * - fixed read/write of MAGN chunk * */
/* * 1.0.5 - 09/14/2002 - G.Juyn * */
/* * - added event handling for dynamic MNG * */
/* * 1.0.5 - 09/15/2002 - G.Juyn * */
/* * - fixed LOOP iteration=0 special case * */
/* * 1.0.5 - 09/19/2002 - G.Juyn * */
/* * - misplaced TERM is now treated as warning * */
/* * 1.0.5 - 09/20/2002 - G.Juyn * */
/* * - added support for PAST * */
/* * 1.0.5 - 10/03/2002 - G.Juyn * */
/* * - fixed chunk-storage for evNT chunk * */
/* * 1.0.5 - 10/07/2002 - G.Juyn * */
/* * - fixed DISC support * */
/* * - added another fix for misplaced TERM chunk * */
/* * 1.0.5 - 10/17/2002 - G.Juyn * */
/* * - fixed initializtion of pIds in dISC read routine * */
/* * 1.0.5 - 11/06/2002 - G.Juyn * */
/* * - added support for nEED "MNG 1.1" * */
/* * - added support for nEED "CACHEOFF" * */
/* * * */
/* * 1.0.6 - 05/25/2003 - G.R-P * */
/* * - added MNG_SKIPCHUNK_cHNK footprint optimizations * */
/* * 1.0.6 - 06/02/2003 - G.R-P * */
/* * - removed some redundant checks for iRawlen==0 * */
/* * 1.0.6 - 06/22/2003 - G.R-P * */
/* * - added MNG_NO_16BIT_SUPPORT, MNG_NO_DELTA_PNG reductions * */
/* * - optionally use zlib's crc32 function instead of * */
/* * local mng_update_crc * */
/* * 1.0.6 - 07/14/2003 - G.R-P * */
/* * - added MNG_NO_LOOP_SIGNALS_SUPPORTED conditional * */
/* * 1.0.6 - 07/29/2003 - G.R-P * */
/* * - added conditionals around PAST chunk support * */
/* * 1.0.6 - 08/17/2003 - G.R-P * */
/* * - added conditionals around non-VLC chunk support * */
/* * * */
/* * 1.0.7 - 10/29/2003 - G.R-P * */
/* * - revised JDAA and JDAT readers to avoid compiler bug * */
/* * 1.0.7 - 01/25/2004 - J.S * */
/* * - added premultiplied alpha canvas' for RGBA, ARGB, ABGR * */
/* * 1.0.7 - 01/27/2004 - J.S * */
/* * - fixed inclusion of IJNG chunk for non-JNG use * */
/* * 1.0.7 - 02/26/2004 - G.Juyn * */
/* * - fixed bug in chunk-storage of SHOW chunk (from == to) * */
/* * * */
/* * 1.0.8 - 04/02/2004 - G.Juyn * */
/* * - added CRC existence & checking flags * */
/* * 1.0.8 - 07/07/2004 - G.R-P * */
/* * - change worst-case iAlphadepth to 1 for standalone PNGs * */
/* * * */
/* ************************************************************************** */
#include "libmng.h"
#include "libmng_data.h"
#include "libmng_error.h"
#include "libmng_trace.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#include "libmng_objects.h"
#include "libmng_object_prc.h"
#include "libmng_chunks.h"
#ifdef MNG_CHECK_BAD_ICCP
#include "libmng_chunk_prc.h"
#endif
#include "libmng_memory.h"
#include "libmng_display.h"
#include "libmng_zlib.h"
#include "libmng_pixels.h"
#include "libmng_chunk_io.h"
#if defined(__BORLANDC__) && defined(MNG_STRICT_ANSI)
#pragma option -A /* force ANSI-C */
#endif
/* ************************************************************************** */
/* * * */
/* * CRC - Cyclic Redundancy Check * */
/* * * */
/* * The code below is taken directly from the sample provided with the * */
/* * PNG specification. * */
/* * (it is only adapted to the library's internal data-definitions) * */
/* * * */
/* ************************************************************************** */
/* Make the table for a fast CRC. */
#ifndef MNG_USE_ZLIB_CRC
MNG_LOCAL void make_crc_table (mng_datap pData)
{
mng_uint32 iC;
mng_int32 iN, iK;
for (iN = 0; iN < 256; iN++)
{
iC = (mng_uint32) iN;
for (iK = 0; iK < 8; iK++)
{
if (iC & 1)
iC = 0xedb88320U ^ (iC >> 1);
else
iC = iC >> 1;
}
pData->aCRCtable [iN] = iC;
}
pData->bCRCcomputed = MNG_TRUE;
}
#endif
/* Update a running CRC with the bytes buf[0..len-1]--the CRC
should be initialized to all 1's, and the transmitted value
is the 1's complement of the final running CRC (see the
crc() routine below). */
MNG_LOCAL mng_uint32 update_crc (mng_datap pData,
mng_uint32 iCrc,
mng_uint8p pBuf,
mng_int32 iLen)
{
#ifdef MNG_USE_ZLIB_CRC
return crc32 (iCrc, pBuf, iLen);
#else
mng_uint32 iC = iCrc;
mng_int32 iN;
if (!pData->bCRCcomputed)
make_crc_table (pData);
for (iN = 0; iN < iLen; iN++)
iC = pData->aCRCtable [(iC ^ pBuf [iN]) & 0xff] ^ (iC >> 8);
return iC;
#endif
}
/* Return the CRC of the bytes buf[0..len-1]. */
mng_uint32 mng_crc (mng_datap pData,
mng_uint8p pBuf,
mng_int32 iLen)
{
#ifdef MNG_USE_ZLIB_CRC
return update_crc (pData, 0, pBuf, iLen);
#else
return update_crc (pData, 0xffffffffU, pBuf, iLen) ^ 0xffffffffU;
#endif
}
/* ************************************************************************** */
/* * * */
/* * Routines for swapping byte-order from and to graphic files * */
/* * (This code is adapted from the libpng package) * */
/* * * */
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