[FFmpeg-trac] #3028(avformat:new): broken conversion yuv444p to bgr24/rgb24

[FFmpeg]

#3028: broken conversion yuv444p to bgr24/rgb24
----------------------------------+--------------------------------------
             Reporter:  chronek   |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avformat  |                  Version:  git-master
             Keywords:  yuv444p   |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
----------------------------------+--------------------------------------
 I found that capturing game and recording with OBS lossless x264 yuv444p
 then converting it with ffmpeg to rgb24 huffyuv or other codec i losing
 color information, with some test i found that problem lies in ffmpeg
 converse yuv444p to rgb24/bgr24 (trying do the same with avisynth script
 gives me colours the same as in game, doing with ffmpeg gives not)

 for reproduce that problem i'll bring something simpler , yuv444p should
 cover all rgb24 colors so doing convert to yuv444p and back to rgb24/bgr24
 should be visual the same, but it is not, i attached 2 samples sc1.bmp and
 sc2.bmp

 ffmpeg -loglevel verbose -i sc1.bmp -vf
 [in]format=yuv444p,format=bgr24[out] out.bmp
 ffmpeg version N-56793-g01e3340 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Sep 30 2013 18:07:49 with gcc 4.8.1 (GCC)
   configuration: --enable-gpl --enable-version3 --disable-w32threads
 --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
 --enable-gnutls --enab
 le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-
 libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-
 libmp3lame --ena
 ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
 --enable-libopus --enable-librtmp --enable-libschroedinger --enable-
 libsoxr --enable-libsp
 eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-
 libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
 --enable-libwavp
 ack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
   libavutil      52. 46.100 / 52. 46.100
   libavcodec     55. 33.101 / 55. 33.101
   libavformat    55. 18.104 / 55. 18.104
   libavdevice    55.  3.100 / 55.  3.100
   libavfilter     3. 88.100 /  3. 88.100
   libswscale      2.  5.100 /  2.  5.100
   libswresample   0. 17.103 /  0. 17.103
   libpostproc    52.  3.100 / 52.  3.100
 Input #0, image2, from 'sc1.bmp':
   Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: bmp, bgr24, 182x188, 25 tbr, 25 tbn, 25 tbc
 File 'out.bmp' already exists. Overwrite ? [y/N] y
 [graph 0 input from stream 0:0 @ 00000000027978a0] w:182 h:188
 pixfmt:bgr24 tb:1/25 fr:25/1 sar:0/1 sws_param:flags=2
 [auto-inserted scaler 0 @ 0000000004614400] w:iw h:ih flags:'0x4' interl:0
 [Parsed_format_0 @ 0000000004628d60] auto-inserting filter 'auto-inserted
 scaler 0' between the filter 'graph 0 input from stream 0:0' and the
 filter 'Parsed_fo
 rmat_0'
 [auto-inserted scaler 1 @ 00000000046146a0] w:iw h:ih flags:'0x4' interl:0
 [Parsed_format_1 @ 0000000002796c60] auto-inserting filter 'auto-inserted
 scaler 1' between the filter 'Parsed_format_0' and the filter
 'Parsed_format_1'
 [auto-inserted scaler 0 @ 0000000004614400] w:182 h:188 fmt:bgr24 sar:0/1
 -> w:182 h:188 fmt:yuv444p sar:0/1 flags:0x4
 [auto-inserted scaler 1 @ 00000000046146a0] w:182 h:188 fmt:yuv444p
 sar:0/1 -> w:182 h:188 fmt:bgr24 sar:0/1 flags:0x4
 Output #0, image2, to 'out.bmp':
   Metadata:
     encoder         : Lavf55.18.104
     Stream #0:0: Video: bmp, bgr24, 182x188, q=2-31, 200 kb/s, 90k tbn, 25
 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (bmp -> bmp)
 Press [q] to stop, [?] for help
 No more output streams to write to, finishing.
 frame=    1 fps=0.0 q=-1.0 Lsize=N/A time=00:00:00.04 bitrate=N/A
 video:101kB audio:0kB subtitle:0 global headers:0kB muxing overhead
 -100.021343%

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/3028>
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