#9573: libx264 ignores color range flag for gray10 input
-------------------------------------+-------------------------------------
Reporter: Diederick | Owner: (none)
Niehorster |
Type: defect | Status: new
Priority: normal | Component: avcodec
Version: git-master | Resolution:
Keywords: libx264 | Blocked By:
gray10 |
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Comment (by Diederick Niehorster):
Thanks both!
It seems that the docs here https://trac.ffmpeg.org/wiki/Encode/H.264 are
wrong then, it says crf 0 is lossless.
I can indeed verify that
{{{
ffmpeg -y -i test.mkv -vf
"scale=in_range=pc:out_range=pc,format=yuv420p10" -c:v libx264 -preset
veryfast -qp 0 test3.mp4
}}}
leads to a losslessly encoded file (yields zero pixel intensity value
errors), super!
Using your commands i have furthermore found that the workaround is not
necessary. full-range gray10 is encoded correctly, it was a playback
issue:
{{{
ffmpeg -y -i test.mkv -c:v libx264 -preset veryfast -qp 0 test3.mp4
}}}
followed by reading in the file with either "-vf extractplanes=y" or "-vf
scale=in_range=pc" yields zero pixel intensity value errors in the output:
input and output are identical.
Note here that with reading in, i mean directly through the api
(demux+decode). Its annoying that the pc scale info is lost by the
automatically inserted filter turning the yuv420p10 back into gray10 /
some rgb format and "-vf scale=in_range=pc" is thus needed. I'll dig into
this to see if its set on the AVFrame delivered by the decoder, etc. Seems
to me like this info should not get lost if its available.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/9573#comment:10>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker_______________________________________________
FFmpeg-trac mailing list
[email protected]
https://ffmpeg.org/mailman/listinfo/ffmpeg-trac
To unsubscribe, visit link above, or email
[email protected] with subject "unsubscribe".
