[FFmpeg-trac] #7978(undetermined:new): inaccurate conversion from YCbCr Narrow range to RGB Full range

[FFmpeg]

#7978: inaccurate conversion from YCbCr Narrow range to RGB Full range
-------------------------------------+-------------------------------------
             Reporter:  cepesh       |                     Type:  defect
               Status:  new          |                 Priority:  important
            Component:               |                  Version:  4.1
  undetermined                       |
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: inaccurate conversion from YCbCr Narrow range to RGB
 Full range
 How to reproduce:
 {{{
 Command line:
 "C:\\tools\\ffmpeg-4.1.3\\bin\\ffmpeg.exe" -loglevel debug -report -s
 3840x2160 -vcodec v210 -i YUV_pattern-2fr.v210 -vf
 "scale=in_color_matrix=bt2020:in_range=tv" -vframes 1 tiff_bug_00.tiff -y
 ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
   built with gcc 8.3.1 (GCC) 20190414
   configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
 fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
 libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-
 amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
 --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora
 --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp
 --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg
 --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-
 libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex
 --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-
 ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec
 --enable-dxva2 --enable-avisynth
   libavutil      56. 22.100 / 56. 22.100
   libavcodec     58. 35.100 / 58. 35.100
   libavformat    58. 20.100 / 58. 20.100
   libavdevice    58.  5.100 / 58.  5.100
   libavfilter     7. 40.101 /  7. 40.101
   libswscale      5.  3.100 /  5.  3.100
   libswresample   3.  3.100 /  3.  3.100
   libpostproc    55.  3.100 / 55.  3.100
 }}}

 100% White
 Source YCbCr value = 0x03ac, 0x0200, 0x0200 (940, 512, 512)
 Observed RGB value = 65283,  65283, 65283
 Expected RGB value = 65535, 65535, 65535


 58% White
 Source YCbCr value = 0x023c, 0x0200, 0x0200 (572, 512, 512)
 Observed RGB value = 37858, 37858, 37858
 Expected RGB value = 38004, 38004, 38004


 100% Magenta
 Source YCbCr value = 0x015a, 0x343, 0x039c
 Observed RGB value = 65280, 0, 65289
 Expected RGB value = 65533, 0, 65535

--
Ticket URL: <https://trac.ffmpeg.org/ticket/7978>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker