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Issue 2021403002: Update libpng to 1.6.22 (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Rearrange pnglibconf.h Created 4 years, 6 months ago
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1 README for libpng version 1.2.56 - December 17, 2015 (shared library 12.0) 1 README for libpng version 1.6.22 - May 26, 2016 (shared library 16.0)
2 See the note about version numbers near the top of png.h 2 See the note about version numbers near the top of png.h
3 3
4 See INSTALL for instructions on how to install libpng. 4 See INSTALL for instructions on how to install libpng.
5 5
6 Libpng comes in several distribution formats. Get libpng-*.tar.gz or 6 Libpng comes in several distribution formats. Get libpng-*.tar.gz or
7 libpng-*.tar.xz if you want UNIX-style line 7 libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
8 endings in the text files, or lpng*.7z or lpng*.zip if you want DOS-style 8 or lpng*.7z or lpng*.zip if you want DOS-style line endings.
9 line endings. You can get UNIX-style line endings from the *.zip file
10 by using "unzip -a" but there seems to be no simple way to recover
11 UNIX-style line endings from the *.7z file. The *.tar.xz file is
12 recommended for *NIX users instead.
13 9
14 Version 0.89 was the first official release of libpng. Don't let the 10 Version 0.89 was the first official release of libpng. Don't let the
15 fact that it's the first release fool you. The libpng library has been in 11 fact that it's the first release fool you. The libpng library has been in
16 extensive use and testing since mid-1995. By late 1997 it had 12 extensive use and testing since mid-1995. By late 1997 it had
17 finally gotten to the stage where there hadn't been significant 13 finally gotten to the stage where there hadn't been significant
18 changes to the API in some time, and people have a bad feeling about 14 changes to the API in some time, and people have a bad feeling about
19 libraries with versions < 1.0. Version 1.0.0 was released in 15 libraries with versions < 1.0. Version 1.0.0 was released in
20 March 1998. 16 March 1998.
21 17
22 **** 18 ****
23 Note that some of the changes to the png_info structure render this 19 Note that some of the changes to the png_info structure render this
24 version of the library binary incompatible with libpng-0.89 or 20 version of the library binary incompatible with libpng-0.89 or
25 earlier versions if you are using a shared library. The type of the 21 earlier versions if you are using a shared library. The type of the
26 "filler" parameter for png_set_filler() has changed from png_byte to 22 "filler" parameter for png_set_filler() has changed from png_byte to
27 png_uint_32, which will affect shared-library applications that use 23 png_uint_32, which will affect shared-library applications that use
28 this function. 24 this function.
29 25
30 To avoid problems with changes to the internals of png_info_struct, 26 To avoid problems with changes to the internals of png info_struct,
31 new APIs have been made available in 0.95 to avoid direct application 27 new APIs have been made available in 0.95 to avoid direct application
32 access to info_ptr. These functions are the png_set_<chunk> and 28 access to info_ptr. These functions are the png_set_<chunk> and
33 png_get_<chunk> functions. These functions should be used when 29 png_get_<chunk> functions. These functions should be used when
34 accessing/storing the info_struct data, rather than manipulating it 30 accessing/storing the info_struct data, rather than manipulating it
35 directly, to avoid such problems in the future. 31 directly, to avoid such problems in the future.
36 32
37 It is important to note that the APIs do not make current programs 33 It is important to note that the APIs did not make current programs
38 that access the info struct directly incompatible with the new 34 that access the info struct directly incompatible with the new
39 library. However, it is strongly suggested that new programs use 35 library, through libpng-1.2.x. In libpng-1.4.x, which was meant to
40 the new APIs (as shown in example.c and pngtest.c), and older programs 36 be a transitional release, members of the png_struct and the
41 be converted to the new format, to facilitate upgrades in the future. 37 info_struct can still be accessed, but the compiler will issue a
38 warning about deprecated usage. Since libpng-1.5.0, direct access
39 to these structs is not allowed, and the definitions of the structs
40 reside in private pngstruct.h and pnginfo.h header files that are not
41 accessible to applications. It is strongly suggested that new
42 programs use the new APIs (as shown in example.c and pngtest.c), and
43 older programs be converted to the new format, to facilitate upgrades
44 in the future.
42 **** 45 ****
43 46
44 Additions since 0.90 include the ability to compile libpng as a 47 Additions since 0.90 include the ability to compile libpng as a
45 Windows DLL, and new APIs for accessing data in the info struct. 48 Windows DLL, and new APIs for accessing data in the info struct.
46 Experimental functions include the ability to set weighting and cost 49 Experimental functions include the ability to set weighting and cost
47 factors for row filter selection, direct reads of integers from buffers 50 factors for row filter selection, direct reads of integers from buffers
48 on big-endian processors that support misaligned data access, faster 51 on big-endian processors that support misaligned data access, faster
49 methods of doing alpha composition, and more accurate 16->8 bit color 52 methods of doing alpha composition, and more accurate 16->8 bit color
50 conversion. 53 conversion.
51 54
52 The additions since 0.89 include the ability to read from a PNG stream 55 The additions since 0.89 include the ability to read from a PNG stream
53 which has had some (or all) of the signature bytes read by the calling 56 which has had some (or all) of the signature bytes read by the calling
54 application. This also allows the reading of embedded PNG streams that 57 application. This also allows the reading of embedded PNG streams that
55 do not have the PNG file signature. As well, it is now possible to set 58 do not have the PNG file signature. As well, it is now possible to set
56 the library action on the detection of chunk CRC errors. It is possible 59 the library action on the detection of chunk CRC errors. It is possible
57 to set different actions based on whether the CRC error occurred in a 60 to set different actions based on whether the CRC error occurred in a
58 critical or an ancillary chunk. 61 critical or an ancillary chunk.
59 62
60 The changes made to the library, and bugs fixed are based on discussions 63 The changes made to the library, and bugs fixed are based on discussions
61 on the png-mng-implement mailing list and not on material submitted 64 on the PNG-implement mailing list and not on material submitted
62 privately to Guy, Andreas, or Glenn. They will forward any good 65 privately to Guy, Andreas, or Glenn. They will forward any good
63 suggestions to the list. 66 suggestions to the list.
64 67
65 For a detailed description on using libpng, read libpng.txt. For 68 For a detailed description on using libpng, read libpng-manual.txt. For
66 examples of libpng in a program, see example.c and pngtest.c. For usage 69 examples of libpng in a program, see example.c and pngtest.c. For usage
67 information and restrictions (what little they are) on libpng, see 70 information and restrictions (what little they are) on libpng, see
68 png.h. For a description on using zlib (the compression library used by 71 png.h. For a description on using zlib (the compression library used by
69 libpng) and zlib's restrictions, see zlib.h 72 libpng) and zlib's restrictions, see zlib.h
70 73
71 I have included a general makefile, as well as several machine and 74 I have included a general makefile, as well as several machine and
72 compiler specific ones, but you may have to modify one for your own needs. 75 compiler specific ones, but you may have to modify one for your own needs.
73 76
74 You should use zlib 1.0.4 or later to run this, but it MAY work with 77 You should use zlib 1.0.4 or later to run this, but it MAY work with
75 versions as old as zlib 0.95. Even so, there are bugs in older zlib 78 versions as old as zlib 0.95. Even so, there are bugs in older zlib
76 versions which can cause the output of invalid compression streams for 79 versions which can cause the output of invalid compression streams for
77 some images. You will definitely need zlib 1.0.4 or later if you are 80 some images. You will definitely need zlib 1.0.4 or later if you are
78 taking advantage of the MS-DOS "far" structure allocation for the small 81 taking advantage of the MS-DOS "far" structure allocation for the small
79 and medium memory models. You should also note that zlib is a 82 and medium memory models. You should also note that zlib is a
80 compression library that is useful for more things than just PNG files. 83 compression library that is useful for more things than just PNG files.
81 You can use zlib as a drop-in replacement for fread() and fwrite() if 84 You can use zlib as a drop-in replacement for fread() and fwrite() if
82 you are so inclined. 85 you are so inclined.
83 86
84 zlib should be available at the same place that libpng is, or at 87 zlib should be available at the same place that libpng is, or at zlib.net.
85 ftp://ftp.simplesystems.org/pub/png/src/
86 88
87 You may also want a copy of the PNG specification. It is available 89 You may also want a copy of the PNG specification. It is available
88 as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find 90 as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
89 these at http://www.libpng.org/pub/png/pngdocs.html 91 these at http://www.libpng.org/pub/png/documents/
90 92
91 This code is currently being archived at libpng.sf.net in the 93 This code is currently being archived at libpng.sf.net in the
92 [DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT) 94 [DOWNLOAD] area, and at ftp://ftp.simplesystems.org. If you can't find it
93 at GO GRAPHSUP. If you can't find it in any of those places, 95 in any of those places, e-mail me, and I'll help you find it.
94 e-mail me, and I'll help you find it.
95 96
96 I am not a lawyer, but I believe that the Export Control Classification 97 I am not a lawyer, but I believe that the Export Control Classification
97 Number (ECCN) for libpng is EAR99, which means not subject to export 98 Number (ECCN) for libpng is EAR99, which means not subject to export
98 controls or International Traffic in Arms Regulations (ITAR) because it 99 controls or International Traffic in Arms Regulations (ITAR) because it
99 is open source, publicly available software, that does not contain any 100 is open source, publicly available software, that does not contain any
100 encryption software. See the EAR, paragraphs 734.3(b)(3) and 734.7(b). 101 encryption software. See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
101 102
102 If you have any code changes, requests, problems, etc., please e-mail 103 If you have any code changes, requests, problems, etc., please e-mail
103 them to me. Also, I'd appreciate any make files or project files, 104 them to me. Also, I'd appreciate any make files or project files,
104 and any modifications you needed to make to get libpng to compile, 105 and any modifications you needed to make to get libpng to compile,
105 along with a #define variable to tell what compiler/system you are on. 106 along with a #define variable to tell what compiler/system you are on.
106 If you needed to add transformations to libpng, or wish libpng would 107 If you needed to add transformations to libpng, or wish libpng would
107 provide the image in a different way, drop me a note (and code, if 108 provide the image in a different way, drop me a note (and code, if
108 possible), so I can consider supporting the transformation. 109 possible), so I can consider supporting the transformation.
109 Finally, if you get any warning messages when compiling libpng 110 Finally, if you get any warning messages when compiling libpng
110 (note: not zlib), and they are easy to fix, I'd appreciate the 111 (note: not zlib), and they are easy to fix, I'd appreciate the
111 fix. Please mention "libpng" somewhere in the subject line. Thanks. 112 fix. Please mention "libpng" somewhere in the subject line. Thanks.
112 113
113 This release was created and will be supported by myself (of course 114 This release was created and will be supported by myself (of course
114 based in a large way on Guy's and Andreas' earlier work), and the PNG 115 based in a large way on Guy's and Andreas' earlier work), and the PNG
115 development group. 116 development group.
116 117
117 Send comments/corrections/commendations to png-mng-implement at lists.sf.net 118 Send comments/corrections/commendations to png-mng-implement at
118 (subscription required; visit 119 lists.sourceforge.net (subscription required; visit
119 https://lists.sourceforge.net/lists/listinfo/png-mng-implement 120 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
120 to subscribe) or to glennrp at users.sourceforge.net 121 to subscribe) or to glennrp at users.sourceforge.net
121 122
122 You can't reach Guy, the original libpng author, at the addresses 123 You can't reach Guy, the original libpng author, at the addresses
123 given in previous versions of this document. He and Andreas will 124 given in previous versions of this document. He and Andreas will
124 read mail addressed to the png-mng-implement list, however. 125 read mail addressed to the png-implement list, however.
125 126
126 Please do not send general questions about PNG. Send them to 127 Please do not send general questions about PNG. Send them to
127 the (png-mng-misc at lists.sourceforge.net, subscription required, visit 128 png-mng-misc at lists.sf.net (subscription required; visit
128 https://lists.sourceforge.net/lists/listinfo/png-mng-misc to 129 https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
129 subscribe). On the other hand, please do not send libpng questions to 130 subscribe). If you have a question about something
130 that address, send them to me or to the png-mng-implement list. I'll
131 get them in the end anyway. If you have a question about something
132 in the PNG specification that is related to using libpng, send it 131 in the PNG specification that is related to using libpng, send it
133 to me. Send me any questions that start with "I was using libpng, 132 to me. Send me any questions that start with "I was using libpng,
134 and ...". If in doubt, send questions to me. I'll bounce them 133 and ...". If in doubt, send questions to me. I'll bounce them
135 to others, if necessary. 134 to others, if necessary.
136 135
137 Please do not send suggestions on how to change PNG. We have 136 Please do not send suggestions on how to change PNG. We have
138 been discussing PNG for twenty years now, and it is official and 137 been discussing PNG for twenty years now, and it is official and
139 finished. If you have suggestions for libpng, however, I'll 138 finished. If you have suggestions for libpng, however, I'll
140 gladly listen. Even if your suggestion is not used immediately, 139 gladly listen. Even if your suggestion is not used immediately,
141 it may be used later. 140 it may be used later.
142 141
143 Files in this distribution: 142 Files in this distribution:
144 143
145 ANNOUNCE => Announcement of this version, with recent changes 144 ANNOUNCE => Announcement of this version, with recent changes
146 CHANGES => Description of changes between libpng versions 145 CHANGES => Description of changes between libpng versions
147 KNOWNBUG => List of known bugs and deficiencies 146 KNOWNBUG => List of known bugs and deficiencies
148 LICENSE => License to use and redistribute libpng 147 LICENSE => License to use and redistribute libpng
149 README => This file 148 README => This file
150 TODO => Things not implemented in the current library 149 TODO => Things not implemented in the current library
151 Y2KINFO => Statement of Y2K compliance 150 Y2KINFO => Statement of Y2K compliance
152 example.c => Example code for using libpng functions 151 example.c => Example code for using libpng functions
153 libpng-*-*-diff.txt => Diff from previous release 152 libpng.3 => manual page for libpng (includes libpng-manual.txt)
154 libpng.3 => manual page for libpng (includes libpng.txt) 153 libpng-manual.txt => Description of libpng and its functions
155 libpng.txt => Description of libpng and its functions
156 libpngpf.3 => manual page for libpng's private functions 154 libpngpf.3 => manual page for libpng's private functions
157 png.5 => manual page for the PNG format 155 png.5 => manual page for the PNG format
158 png.c => Basic interface functions common to library 156 png.c => Basic interface functions common to library
159 png.h => Library function and interface declarations 157 png.h => Library function and interface declarations (public)
160 pngconf.h => System specific library configuration 158 pngpriv.h => Library function and interface declarations (private)
159 pngconf.h => System specific library configuration (public)
160 pngstruct.h => png_struct declaration (private)
161 pnginfo.h => png_info struct declaration (private)
162 pngdebug.h => debugging macros (private)
161 pngerror.c => Error/warning message I/O functions 163 pngerror.c => Error/warning message I/O functions
162 pngget.c => Functions for retrieving info from struct 164 pngget.c => Functions for retrieving info from struct
163 pngmem.c => Memory handling functions 165 pngmem.c => Memory handling functions
164 pngbar.png => PNG logo, 88x31 166 pngbar.png => PNG logo, 88x31
165 pngnow.png => PNG logo, 98x31 167 pngnow.png => PNG logo, 98x31
166 pngpread.c => Progressive reading functions 168 pngpread.c => Progressive reading functions
167 pngread.c => Read data/helper high-level functions 169 pngread.c => Read data/helper high-level functions
168 pngrio.c => Lowest-level data read I/O functions 170 pngrio.c => Lowest-level data read I/O functions
169 pngrtran.c => Read data transformation functions 171 pngrtran.c => Read data transformation functions
170 pngrutil.c => Read data utility functions 172 pngrutil.c => Read data utility functions
171 pngset.c => Functions for storing data into the info_struct 173 pngset.c => Functions for storing data into the info_struct
172 pngtest.c => Library test program 174 pngtest.c => Library test program
173 pngtest.png => Library test sample image 175 pngtest.png => Library test sample image
174 pngtrans.c => Common data transformation functions 176 pngtrans.c => Common data transformation functions
175 pngwio.c => Lowest-level write I/O functions 177 pngwio.c => Lowest-level write I/O functions
176 pngwrite.c => High-level write functions 178 pngwrite.c => High-level write functions
177 pngwtran.c => Write data transformations 179 pngwtran.c => Write data transformations
178 pngwutil.c => Write utility functions 180 pngwutil.c => Write utility functions
181 arm => Contains optimized code for the ARM platform
179 contrib => Contributions 182 contrib => Contributions
183 examples => Example programs
180 gregbook => source code for PNG reading and writing, from 184 gregbook => source code for PNG reading and writing, from
181 Greg Roelofs' "PNG: The Definitive Guide", 185 Greg Roelofs' "PNG: The Definitive Guide",
182 O'Reilly, 1999 186 O'Reilly, 1999
183 pngminim => Minimal pnm2pngm and png2pnmm programs 187 libtests => Test programs
184 pngminus => Simple pnm2png and png2pnm programs 188 pngminim => Minimal decoder, encoder, and progressive decoder
185 pngsuite => Test images 189 programs demonstrating use of pngusr.dfa
186 visupng => Contains a MSVC workspace for VisualPng 190 pngminus => Simple pnm2png and png2pnm programs
191 pngsuite => Test images
192 tools => Various tools
193 visupng => Contains a MSVC workspace for VisualPng
187 projects => Contains project files and workspaces for 194 projects => Contains project files and workspaces for
188 building a DLL 195 building a DLL
189 beos => Contains a Beos workspace for building libpng 196 owatcom => Contains a WATCOM project for building libpng
190 c5builder => Contains a Borland workspace for building
191 libpng and zlib
192 MacOSX => Contains a MacOSX workspace for building libpng
193 netware.txt => Contains instructions for downloading a set
194 of project files for building libpng and
195 zlib on Netware.
196 visualc6 => Contains a Microsoft Visual C++ (MSVC)
197 workspace for building libpng and zlib
198 visualc71 => Contains a Microsoft Visual C++ (MSVC) 197 visualc71 => Contains a Microsoft Visual C++ (MSVC)
199 workspace for building libpng and zlib 198 workspace for building libpng and zlib
200 wince.txt => Contains instructions for downloading a 199 vstudio => Contains a Microsoft Visual C++ (MSVC)
201 Microsoft Visual C++ (Windows CD Toolkit) 200 workspace for building libpng and zlib
202 workspace for building libpng and zlib on
203 WindowsCE
204 xcode => Contains xcode project files
205 scripts => Directory containing scripts for building libpng: 201 scripts => Directory containing scripts for building libpng:
206 descrip.mms => VMS makefile for MMS or MMK 202 (see scripts/README.txt for the list of scripts)
207 makefile.std => Generic UNIX makefile (cc, creates static
208 libpng.a)
209 makefile.elf => Linux/ELF gcc makefile symbol versioning,
210 creates libpng12.so.0.1.2.56)
211 makefile.linux => Linux/ELF makefile (gcc, creates
212 libpng12.so.0.1.2.56)
213 makefile.gcmmx => Linux/ELF makefile (gcc, creates
214 libpng12.so.0.1.2.56, previously
215 used assembler code tuned for Intel MMX
216 platform)
217 makefile.gcc => Generic makefile (gcc, creates static
218 libpng.a)
219 makefile.knr => Archaic UNIX Makefile that converts files
220 with ansi2knr (Requires ansi2knr.c from
221 ftp://ftp.cs.wisc.edu/ghost)
222 makefile.aix => AIX makefile
223 makefile.cygwin => Cygwin/gcc makefile
224 makefile.darwin => Darwin makefile
225 makefile.dec => DEC Alpha UNIX makefile
226 makefile.freebsd => FreeBSD makefile
227 makefile.hpgcc => HPUX makefile using gcc
228 makefile.hpux => HPUX (10.20 and 11.00) makefile
229 makefile.hp64 => HPUX (10.20 and 11.00) makefile, 64 bit
230 makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2
231 (static)
232 makefile.intel => Intel C/C++ version 4.0 and later
233 libpng.icc => Project file, IBM VisualAge/C++ 4.0 or later
234 makefile.netbsd => NetBSD/cc makefile, makes libpng.so.
235 makefile.ne12bsd => NetBSD/cc makefile, makes libpng12.so
236 makefile.openbsd => OpenBSD makefile
237 makefile.sgi => Silicon Graphics IRIX (cc, creates static lib)
238 makefile.sggcc => Silicon Graphics
239 (gcc, creates libpng12.so.0.1.2.56)
240 makefile.sunos => Sun makefile
241 makefile.solaris => Solaris 2.X makefile
242 (gcc, creates libpng12.so.0.1.2.56)
243 makefile.so9 => Solaris 9 makefile
244 (gcc, creates libpng12.so.0.1.2.56)
245 makefile.32sunu => Sun Ultra 32-bit makefile
246 makefile.64sunu => Sun Ultra 64-bit makefile
247 makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
248 makefile.mips => MIPS makefile
249 makefile.acorn => Acorn makefile
250 makefile.amiga => Amiga makefile
251 smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC
252 compiler (Requires SCOPTIONS, copied from
253 scripts/SCOPTIONS.ppc)
254 makefile.atari => Atari makefile
255 makefile.beos => BEOS makefile for X86
256 makefile.bor => Borland makefile (uses bcc)
257 makefile.bc32 => 32-bit Borland C++ (all modules compiled in C mode)
258 makefile.tc3 => Turbo C 3.0 makefile
259 makefile.dj2 => DJGPP 2 makefile
260 makefile.msc => Microsoft C makefile
261 makefile.vcawin32=> makefile for Microsoft Visual C++ 5.0 and
262 later (previously used assembler code tuned
263 for Intel MMX platform)
264 makefile.vcwin32 => makefile for Microsoft Visual C++ 4.0 and
265 later (does not use assembler code)
266 makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def)
267 pngos2.def => OS/2 module definition file used by makefile.os2
268 makefile.watcom => Watcom 10a+ Makefile, 32-bit flat memory model
269 makevms.com => VMS build script
270 SCOPTIONS.ppc => Used with smakefile.ppc
271 203
272 Good luck, and happy coding. 204 Good luck, and happy coding.
273 205
274 -Glenn Randers-Pehrson (current maintainer, since 1998) 206 -Glenn Randers-Pehrson (current maintainer, since 1998)
275 Internet: glennrp at users.sourceforge.net 207 Internet: glennrp at users.sourceforge.net
276 208
277 -Andreas Eric Dilger (former maintainer, 1996-1997) 209 -Andreas Eric Dilger (former maintainer, 1996-1997)
278 Internet: adilger at enel.ucalgary.ca 210 Internet: adilger at enel.ucalgary.ca
279 Web: http://members.shaw.ca/adilger/ 211 Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
280 212
281 -Guy Eric Schalnat (original author and former maintainer, 1995-1996) 213 -Guy Eric Schalnat (original author and former maintainer, 1995-1996)
282 (formerly of Group 42, Inc) 214 (formerly of Group 42, Inc)
283 Internet: gschal at infinet.com 215 Internet: gschal at infinet.com
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