[FFmpeg-trac] #769(undetermined:new): png gray8 alpha decodes incorrectly

[FFmpeg]

#769: png gray8 alpha decodes incorrectly
-------------------------------------+-------------------------------------
             Reporter:  ami_stuff    |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
              Version:  unspecified  |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------

Comment (by ami_stuff):

 {{{
 C:\>ffmpeg -i basi4a08.png ffmpeg.bmp
 ffmpeg version N-35709-g7d531e8, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Dec 12 2011 13:50:00 with gcc 4.6.2
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-ru
 ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-
 libope
 ncore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-
 libgsm --en
 able-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-
 libschroedinger -
 -enable-libspeex --enable-libtheora --enable-libvo-aacenc --enable-libvo-
 amrwben
 c --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs
 --enable-
 libxvid --enable-zlib
   libavutil    51. 32. 0 / 51. 32. 0
   libavcodec   53. 43. 0 / 53. 43. 0
   libavformat  53. 24. 0 / 53. 24. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 53. 0 /  2. 53. 0
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 Input #0, image2, from 'basi4a08.png':
   Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: png, gray8a, 32x32, 25 tbr, 25 tbn, 25 tbc
 Incompatible pixel format 'gray8a' for codec 'bmp', auto-selecting format
 'bgr24
 '
 [buffer @ 020D1700] w:32 h:32 pixfmt:gray8a tb:1/1000000 sar:0/1
 sws_param:
 [buffersink @ 020D1980] auto-inserting filter 'auto-inserted scale 0'
 between th
 e filter 'src' and the filter 'out'
 [scale @ 020D1D80] w:32 h:32 fmt:gray8a -> w:32 h:32 fmt:bgr24 flags:0x4
 Output #0, image2, to 'ffmpeg.bmp':
   Metadata:
     encoder         : Lavf53.24.0
     Stream #0:0: Video: bmp, bgr24, 32x32, q=2-31, 200 kb/s, 90k tbn, 25
 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (png -> bmp)
 Press [q] to stop, [?] for help
 frame=    1 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.04 bitrate=
 0.0kbits/
 s
 video:3kB audio:0kB global headers:0kB muxing overhead -100.000000%
 }}}

 {{{
 C:\>ffplay basi4a08.png
 ffplay version N-35709-g7d531e8, Copyright (c) 2003-2011 the FFmpeg
 developers
   built on Dec 12 2011 13:50:00 with gcc 4.6.2
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-ru
 ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-
 libope
 ncore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-
 libgsm --en
 able-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-
 libschroedinger -
 -enable-libspeex --enable-libtheora --enable-libvo-aacenc --enable-libvo-
 amrwben
 c --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs
 --enable-
 libxvid --enable-zlib
   libavutil    51. 32. 0 / 51. 32. 0
   libavcodec   53. 43. 0 / 53. 43. 0
   libavformat  53. 24. 0 / 53. 24. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 53. 0 /  2. 53. 0
   libswscale    2.  1. 0 /  2.  1. 0
   libpostproc  51.  2. 0 / 51.  2. 0
 Input #0, image2, from 'basi4a08.png':
   Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: png, gray8a, 32x32, 25 tbr, 25 tbn, 25 tbc
 [buffersink @ 020D2880] auto-inserting filter 'auto-inserted scale 0'
 between th
 e filter 'src' and the filter 'out'
 [scale @ 020D2CA0] w:32 h:32 fmt:gray8a -> w:32 h:32 fmt:yuv420p flags:0x4
    1.44 A-V:  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/769#comment:3>
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