Libpng 1.5.7rc02 - December 5, 2011 This is not intended to be a public release. It will be replaced within a few weeks by a public version or by another test version. Files available for download: Source files with LF line endings (for Unix/Linux) and with a "configure" script 1.5.7rc02.tar.xz (LZMA-compressed, recommended) 1.5.7rc02.tar.gz 1.5.7rc02.tar.bz2 Source files with CRLF line endings (for Windows), without the "configure" script lp157r02.7z (LZMA-compressed, recommended) lp157r02.zip Other information: 1.5.7rc02-README.txt 1.5.7rc02-LICENSE.txt Changes since the last public release (1.5.6): Version 1.5.7beta01 [November 4, 2011] Added support for ARM processor (Mans Rullgard) Fixed bug in pngvalid on early allocation failure; fixed type cast in pngmem.c; pngvalid would attempt to call png_error() if the allocation of a png_struct or png_info failed. This would probably have led to a crash. The pngmem.c implementation of png_malloc() included a cast to png_size_t which would fail on large allocations on 16-bit systems. Fix for the preprocessor of the Intel C compiler. The preprocessor splits adjacent @ signs with a space; this changes the concatentation token from @-@-@ to PNG_JOIN; that should work with all compiler preprocessors. Paeth filter speed improvements from work by Siarhei Siamashka. This changes the 'Paeth' reconstruction function to improve the GCC code generation on x86. The changes are only part of the suggested ones; just the changes that definitely improve speed and remain simple. The changes also slightly increase the clarity of the code. Version 1.5.7beta02 [November 11, 2011] Check compression_type parameter in png_get_iCCP and remove spurious casts. The compression_type parameter is always assigned to, so must be non-NULL. The cast of the profile length potentially truncated the value unnecessarily on a 16-bit int system, so the cast of the (byte) compression type to (int) is specified by ANSI-C anyway. Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left the sBIT fields in the test pixel as 0, which resulted in a floating point division by zero which was irrelevant but causes systems where FP exceptions cause a crash. Added code to pngvalid to turn on FP exceptions if the appropriate glibc support is there to ensure this is tested in the future. Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the new PNG_JOIN macro. Added versioning to pnglibconf.h comments. Simplified read/write API initial version; basic read/write tested on a variety of images, limited documentation (in the header file.) Installed more accurate linear to sRGB conversion tables. The slightly modified tables reduce the number of 16-bit values that convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used to generate the tables is now in a contrib/sRGBtables sub-directory. Version 1.5.7beta03 [November 17, 2011] Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c Added run-time detection of NEON support. Added contrib/libtests; includes simplified API test and timing test and a color conversion utility for rapid checking of failed 'pngstest' results. Multiple transform bug fixes plus a work-round for double gamma correction. libpng does not support more than one transform that requires linear data at once - if this is tried typically the results is double gamma correction. Since the simplified APIs can need rgb to gray combined with a compose operation it is necessary to do one of these outside the main libpng transform code. This check-in also contains fixes to various bugs in the simplified APIs themselves and to some bugs in compose and rgb to gray (on palette) itself. Fixes for C++ compilation using g++ When libpng source is compiled using g++. The compiler imposes C++ rules on the C source; thus it is desireable to make the source work with either C or C++ rules without throwing away useful error information. This change adds png_voidcast to allow C semantic (void*) cases or the corresponding C++ static_cast operation, as appropriate. Added --noexecstack to assembler file compilation. GCC does not set this on assembler compilation, even though it does on C compilation. This creates security issues if assembler code is enabled; the work-around is to set it by default in the flags for $(CCAS) Work around compilers that don't support declaration of const data. Some compilers fault 'extern const' data declarations (because the data is not initialized); this turns on const-ness only for compilers where this is known to work. Version 1.5.7beta04 [November 17, 2011] Since the gcc driver does not recognize the --noexecstack flag, we must use the -Wa prefix to have it passed through to the assembler. Also removed a duplicate setting of this flag. Added files that were omitted from the libpng-1.5.7beta03 zip distribution. Version 1.5.7beta05 [November 25, 2011] Removed "zTXt" from warning in generic chunk decompression function. Validate time settings passed to pngset() and png_convert_to_rfc1123() (Frank Busse). Added MINGW support to CMakeLists.txt Reject invalid compression flag or method when reading the iTXt chunk. Backed out 'simplified' API changes. The API seems too complex and there is a lack of consensus or enthusiasm for the proposals. The API also reveals significant bugs inside libpng (double gamma correction and the known bug of being unable to retrieve a corrected palette). It seems better to wait until the bugs, at least, are corrected. Moved pngvalid.c into contrib/libtests Rebuilt Makefile.in, configure, etc., with autoconf-2.68 Version 1.5.7rc01 [December 1, 2011] Replaced an "#if" with "#ifdef" in pngrtran.c Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else) Version 1.5.7rc02 [December 5, 2011] Revised project files and contrib/pngvalid/pngvalid.c to account for the relocation of pngvalid into contrib/libtests. Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400, as in libpng-1.5.4. Put CRLF line endings in the owatcom project files. Send comments/corrections/commendations to png-mng-implement at lists.sf.net: (subscription required; visit https://lists.sourceforge.net/lists/listinfo/png-mng-implement to subscribe) or to glennrp at users.sourceforge.net Glenn R-P