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Android.mk24-Aug-20163.9K
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arm/24-Aug-2016
autogen.sh24-Aug-20167.8K
CHANGES24-Aug-2016271.1K
CleanSpec.mk24-Aug-20162.2K
CMakeLists.txt24-Aug-201629.6K
configure.ac24-Aug-201611.5K
contrib/24-Aug-2016
example.c24-Aug-201639.4K
INSTALL24-Aug-201617.7K
libpng-config.in24-Aug-20162.3K
libpng-manual.txt24-Aug-2016222.6K
libpng.324-Aug-2016264.1K
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LICENSE24-Aug-20164.8K
Makefile.am24-Aug-201612.7K
MODULE_LICENSE_BSD_LIKE24-Aug-20160
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png.c24-Aug-2016149.9K
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pnginfo.h24-Aug-201612.1K
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pngread.c24-Aug-2016136.3K
pngrio.c24-Aug-20163.9K
pngrtran.c24-Aug-2016164.6K
pngrutil.c24-Aug-2016139.4K
pngset.c24-Aug-201648.7K
pngstruct.h24-Aug-201619.6K
pngtest.c24-Aug-201659.3K
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pngwrite.c24-Aug-201674.2K
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README24-Aug-201611K
README.android24-Aug-2016465
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TODO24-Aug-20161.2K

README

      1 README for libpng version 1.6.22beta03 - February 8, 2016 (shared library 16.0)
      2 See the note about version numbers near the top of png.h
      3 
      4 See INSTALL for instructions on how to install libpng.
      5 
      6 Libpng comes in several distribution formats.  Get libpng-*.tar.gz or
      7 libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
      8 or lpng*.7z or lpng*.zip if you want DOS-style line endings.
      9 
     10 Version 0.89 was the first official release of libpng.  Don't let the
     11 fact that it's the first release fool you.  The libpng library has been in
     12 extensive use and testing since mid-1995.  By late 1997 it had
     13 finally gotten to the stage where there hadn't been significant
     14 changes to the API in some time, and people have a bad feeling about
     15 libraries with versions < 1.0.  Version 1.0.0 was released in
     16 March 1998.
     17 
     18 ****
     19 Note that some of the changes to the png_info structure render this
     20 version of the library binary incompatible with libpng-0.89 or
     21 earlier versions if you are using a shared library.  The type of the
     22 "filler" parameter for png_set_filler() has changed from png_byte to
     23 png_uint_32, which will affect shared-library applications that use
     24 this function.
     25 
     26 To avoid problems with changes to the internals of png info_struct,
     27 new APIs have been made available in 0.95 to avoid direct application
     28 access to info_ptr.  These functions are the png_set_<chunk> and
     29 png_get_<chunk> functions.  These functions should be used when
     30 accessing/storing the info_struct data, rather than manipulating it
     31 directly, to avoid such problems in the future.
     32 
     33 It is important to note that the APIs did not make current programs
     34 that access the info struct directly incompatible with the new
     35 library, through libpng-1.2.x.  In libpng-1.4.x, which was meant to
     36 be a transitional release, members of the png_struct and the
     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.
     45 ****
     46 
     47 Additions since 0.90 include the ability to compile libpng as a
     48 Windows DLL, and new APIs for accessing data in the info struct.
     49 Experimental functions include the ability to set weighting and cost
     50 factors for row filter selection, direct reads of integers from buffers
     51 on big-endian processors that support misaligned data access, faster
     52 methods of doing alpha composition, and more accurate 16->8 bit color
     53 conversion.
     54 
     55 The additions since 0.89 include the ability to read from a PNG stream
     56 which has had some (or all) of the signature bytes read by the calling
     57 application.  This also allows the reading of embedded PNG streams that
     58 do not have the PNG file signature.  As well, it is now possible to set
     59 the library action on the detection of chunk CRC errors.  It is possible
     60 to set different actions based on whether the CRC error occurred in a
     61 critical or an ancillary chunk.
     62 
     63 The changes made to the library, and bugs fixed are based on discussions
     64 on the PNG-implement mailing list and not on material submitted
     65 privately to Guy, Andreas, or Glenn.  They will forward any good
     66 suggestions to the list.
     67 
     68 For a detailed description on using libpng, read libpng-manual.txt.  For
     69 examples of libpng in a program, see example.c and pngtest.c.  For usage
     70 information and restrictions (what little they are) on libpng, see
     71 png.h.  For a description on using zlib (the compression library used by
     72 libpng) and zlib's restrictions, see zlib.h
     73 
     74 I have included a general makefile, as well as several machine and
     75 compiler specific ones, but you may have to modify one for your own needs.
     76 
     77 You should use zlib 1.0.4 or later to run this, but it MAY work with
     78 versions as old as zlib 0.95.  Even so, there are bugs in older zlib
     79 versions which can cause the output of invalid compression streams for
     80 some images.  You will definitely need zlib 1.0.4 or later if you are
     81 taking advantage of the MS-DOS "far" structure allocation for the small
     82 and medium memory models.  You should also note that zlib is a
     83 compression library that is useful for more things than just PNG files.
     84 You can use zlib as a drop-in replacement for fread() and fwrite() if
     85 you are so inclined.
     86 
     87 zlib should be available at the same place that libpng is, or at zlib.net.
     88 
     89 You may also want a copy of the PNG specification.  It is available
     90 as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
     91 these at http://www.libpng.org/pub/png/documents/
     92 
     93 This code is currently being archived at libpng.sf.net in the
     94 [DOWNLOAD] area, and at ftp://ftp.simplesystems.org.  If you can't find it
     95 in any of those places, e-mail me, and I'll help you find it.
     96 
     97 I am not a lawyer, but I believe that the Export Control Classification
     98 Number (ECCN) for libpng is EAR99, which means not subject to export
     99 controls or International Traffic in Arms Regulations (ITAR) because it
    100 is open source, publicly available software, that does not contain any
    101 encryption software.  See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
    102 
    103 If you have any code changes, requests, problems, etc., please e-mail
    104 them to me.  Also, I'd appreciate any make files or project files,
    105 and any modifications you needed to make to get libpng to compile,
    106 along with a #define variable to tell what compiler/system you are on.
    107 If you needed to add transformations to libpng, or wish libpng would
    108 provide the image in a different way, drop me a note (and code, if
    109 possible), so I can consider supporting the transformation.
    110 Finally, if you get any warning messages when compiling libpng
    111 (note: not zlib), and they are easy to fix, I'd appreciate the
    112 fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
    113 
    114 This release was created and will be supported by myself (of course
    115 based in a large way on Guy's and Andreas' earlier work), and the PNG
    116 development group.
    117 
    118 Send comments/corrections/commendations to png-mng-implement at
    119 lists.sourceforge.net (subscription required; visit
    120 https://lists.sourceforge.net/lists/listinfo/png-mng-implement
    121 to subscribe) or to glennrp at users.sourceforge.net
    122 
    123 You can't reach Guy, the original libpng author, at the addresses
    124 given in previous versions of this document.  He and Andreas will
    125 read mail addressed to the png-implement list, however.
    126 
    127 Please do not send general questions about PNG.  Send them to
    128 png-mng-misc at lists.sf.net (subscription required; visit
    129 https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
    130 subscribe).  If you have a question about something
    131 in the PNG specification that is related to using libpng, send it
    132 to me.  Send me any questions that start with "I was using libpng,
    133 and ...".  If in doubt, send questions to me.  I'll bounce them
    134 to others, if necessary.
    135 
    136 Please do not send suggestions on how to change PNG.  We have
    137 been discussing PNG for twenty years now, and it is official and
    138 finished.  If you have suggestions for libpng, however, I'll
    139 gladly listen.  Even if your suggestion is not used immediately,
    140 it may be used later.
    141 
    142 Files in this distribution:
    143 
    144       ANNOUNCE      =>  Announcement of this version, with recent changes
    145       CHANGES       =>  Description of changes between libpng versions
    146       KNOWNBUG      =>  List of known bugs and deficiencies
    147       LICENSE       =>  License to use and redistribute libpng
    148       README        =>  This file
    149       TODO          =>  Things not implemented in the current library
    150       Y2KINFO       =>  Statement of Y2K compliance
    151       example.c     =>  Example code for using libpng functions
    152       libpng.3      =>  manual page for libpng (includes libpng-manual.txt)
    153       libpng-manual.txt  =>  Description of libpng and its functions
    154       libpngpf.3    =>  manual page for libpng's private functions
    155       png.5         =>  manual page for the PNG format
    156       png.c         =>  Basic interface functions common to library
    157       png.h         =>  Library function and interface declarations (public)
    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)
    163       pngerror.c    =>  Error/warning message I/O functions
    164       pngget.c      =>  Functions for retrieving info from struct
    165       pngmem.c      =>  Memory handling functions
    166       pngbar.png    =>  PNG logo, 88x31
    167       pngnow.png    =>  PNG logo, 98x31
    168       pngpread.c    =>  Progressive reading functions
    169       pngread.c     =>  Read data/helper high-level functions
    170       pngrio.c      =>  Lowest-level data read I/O functions
    171       pngrtran.c    =>  Read data transformation functions
    172       pngrutil.c    =>  Read data utility functions
    173       pngset.c      =>  Functions for storing data into the info_struct
    174       pngtest.c     =>  Library test program
    175       pngtest.png   =>  Library test sample image
    176       pngtrans.c    =>  Common data transformation functions
    177       pngwio.c      =>  Lowest-level write I/O functions
    178       pngwrite.c    =>  High-level write functions
    179       pngwtran.c    =>  Write data transformations
    180       pngwutil.c    =>  Write utility functions
    181       arm           =>  Contains optimized code for the ARM platform
    182       contrib       =>  Contributions
    183        examples         =>  Example programs
    184        gregbook         =>  source code for PNG reading and writing, from
    185                             Greg Roelofs' "PNG: The Definitive Guide",
    186                             O'Reilly, 1999
    187        libtests         =>  Test programs
    188        pngminim         =>  Minimal decoder, encoder, and progressive decoder
    189                             programs demonstrating use of pngusr.dfa
    190        pngminus         =>  Simple pnm2png and png2pnm programs
    191        pngsuite         =>  Test images
    192        tools            =>  Various tools
    193        visupng          =>  Contains a MSVC workspace for VisualPng
    194       projects      =>  Contains project files and workspaces for
    195                         building a DLL
    196        owatcom          =>  Contains a WATCOM project for building libpng
    197        visualc71        =>  Contains a Microsoft Visual C++ (MSVC)
    198                             workspace for building libpng and zlib
    199        vstudio          =>  Contains a Microsoft Visual C++ (MSVC)
    200                             workspace for building libpng and zlib
    201       scripts       =>  Directory containing scripts for building libpng:
    202                             (see scripts/README.txt for the list of scripts)
    203 
    204 Good luck, and happy coding.
    205 
    206 -Glenn Randers-Pehrson (current maintainer, since 1998)
    207  Internet: glennrp at users.sourceforge.net
    208 
    209 -Andreas Eric Dilger (former maintainer, 1996-1997)
    210  Internet: adilger at enel.ucalgary.ca
    211  Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
    212 
    213 -Guy Eric Schalnat (original author and former maintainer, 1995-1996)
    214  (formerly of Group 42, Inc)
    215  Internet: gschal at infinet.com
    216 

README.android

      1 Any Android specific modifications to upstream libpng (1.6.22beta) should
      2 be listed here:
      3 
      4 (1) Android has added the following files.
      5     pngusr.h
      6     Android.mk
      7     CleanSpec.mk
      8     MODULE_LICENSE_BSD_LIKE
      9     README.version
     10 
     11 (2) pnglibconf.h
     12     This is copied from scripts/pnglibconf.h.prebuilt.
     13     Android has undefined PNG_WARNINGS_SUPPORTED.
     14 
     15 (3) Removed contrib/testpngs/
     16     There is no reason to check in all of these files if we won't
     17     be using them.
     18 

README.version

      1 URL: https://sourceforge.net/projects/libpng/files/libpng16/1.6.22beta02/libpng-1.6.22beta02.tar.gz/download
      2 Version: 1.6.22beta
      3 BugComponent: 87896
      4