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84
README
84
README
@@ -4,12 +4,12 @@ See the note about version numbers near the top of png.h.
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See INSTALL for instructions on how to install libpng.
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Libpng comes in several distribution formats. Get libpng-*.tar.gz or
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libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
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or lpng*.7z or lpng*.zip if you want DOS-style line endings.
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libpng-*.tar.xz or if you want UNIX-style line endings in the text
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files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
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Version 0.89 was the first official release of libpng. Don't let the
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fact that it's the first release fool you. The libpng library has been in
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extensive use and testing since mid-1995. By late 1997 it had
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fact that it's the first release fool you. The libpng library has been
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in extensive use and testing since mid-1995. By late 1997 it had
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finally gotten to the stage where there hadn't been significant
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changes to the API in some time, and people have a bad feeling about
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libraries with versions < 1.0. Version 1.0.0 was released in
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@@ -60,84 +60,48 @@ the library action on the detection of chunk CRC errors. It is possible
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to set different actions based on whether the CRC error occurred in a
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critical or an ancillary chunk.
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The changes made to the library, and bugs fixed are based on discussions
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on the PNG-implement mailing list and not on material submitted
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privately to Guy, Andreas, or Glenn. They will forward any good
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suggestions to the list.
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For a detailed description on using libpng, read libpng-manual.txt. For
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examples of libpng in a program, see example.c and pngtest.c. For usage
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information and restrictions (what little they are) on libpng, see
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png.h. For a description on using zlib (the compression library used by
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libpng) and zlib's restrictions, see zlib.h
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For a detailed description on using libpng, read libpng-manual.txt.
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For examples of libpng in a program, see example.c and pngtest.c. For
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usage information and restrictions (what little they are) on libpng,
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see png.h. For a description on using zlib (the compression library
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used by libpng) and zlib's restrictions, see zlib.h
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I have included a general makefile, as well as several machine and
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compiler specific ones, but you may have to modify one for your own needs.
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compiler specific ones, but you may have to modify one for your own
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needs.
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You should use zlib 1.0.4 or later to run this, but it MAY work with
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versions as old as zlib 0.95. Even so, there are bugs in older zlib
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versions which can cause the output of invalid compression streams for
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some images. You will definitely need zlib 1.0.4 or later if you are
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taking advantage of the MS-DOS "far" structure allocation for the small
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and medium memory models. You should also note that zlib is a
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compression library that is useful for more things than just PNG files.
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You can use zlib as a drop-in replacement for fread() and fwrite() if
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you are so inclined.
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some images.
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zlib should be available at the same place that libpng is, or at zlib.net.
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You should also note that zlib is a compression library that is useful
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for more things than just PNG files. You can use zlib as a drop-in
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replacement for fread() and fwrite(), if you are so inclined.
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zlib should be available at the same place that libpng is, or at
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https://zlib.net.
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You may also want a copy of the PNG specification. It is available
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as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
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these at http://www.libpng.org/pub/png/pngdocs.html .
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This code is currently being archived at libpng.sourceforge.io in the
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[DOWNLOAD] area, and at http://libpng.download/src . If you
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can't find it in any of those places, e-mail me, and I'll help you find it.
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I am not a lawyer, but I believe that the Export Control Classification
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Number (ECCN) for libpng is EAR99, which means not subject to export
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controls or International Traffic in Arms Regulations (ITAR) because it
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is open source, publicly available software, that does not contain any
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encryption software. See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
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If you have any code changes, requests, problems, etc., please e-mail
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them to me. Also, I'd appreciate any make files or project files,
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and any modifications you needed to make to get libpng to compile,
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along with a #define variable to tell what compiler/system you are on.
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If you needed to add transformations to libpng, or wish libpng would
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provide the image in a different way, drop me a note (and code, if
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possible), so I can consider supporting the transformation.
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Finally, if you get any warning messages when compiling libpng
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(note: not zlib), and they are easy to fix, I'd appreciate the
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fix. Please mention "libpng" somewhere in the subject line. Thanks.
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[DOWNLOAD] area, and at http://libpng.download/src .
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This release was created and will be supported by myself (of course
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based in a large way on Guy's and Andreas' earlier work), and the PNG
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development group.
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based in a large way on Glenn's, Guy's and Andreas' earlier work), and
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the PNG development group.
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Send comments/corrections/commendations to png-mng-implement at
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lists.sourceforge.net (subscription required; visit
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https://lists.sourceforge.net/lists/listinfo/png-mng-implement
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to subscribe).
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You can't reach Guy, the original libpng author, at the addresses
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given in previous versions of this document. He and Andreas will
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read mail addressed to the png-implement list, however.
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Please do not send general questions about PNG. Send them to
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png-mng-misc at lists.sf.net (subscription required; visit
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Send general questions about the PNG specification to png-mng-misc
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at lists.sourceforge.net (subscription required; visit
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https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
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subscribe). If you have a question about something
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in the PNG specification that is related to using libpng, send it
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to me. Send me any questions that start with "I was using libpng,
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and ...". If in doubt, send questions to me. I'll bounce them
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to others, if necessary.
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Please do not send suggestions on how to change PNG. We have
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been discussing PNG for twenty years now, and it is official and
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finished. If you have suggestions for libpng, however, I'll
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gladly listen. Even if your suggestion is not used immediately,
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it may be used later.
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subscribe).
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Files in this distribution:
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