[FFmpeg-trac] #225(undetermined:open): Converting from YUVJ to YUV lose contrast
FFmpeg
trac at avcodec.org
Sat May 21 09:51:24 CEST 2011
#225: Converting from YUVJ to YUV lose contrast
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Reporter: sghpunk | Owner:
Type: defect | Status: open
Priority: normal | Component: undetermined
Version: git-master | Resolution:
Keywords: YUV/YUVJ contrast | Blocked By:
Blocking: | Reproduced: 0
Analyzed: 0 |
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Comment (by sghpunk):
I do the same, as you described.
And I can say... It is more complicated, than I thought...
(ffmpeg -i out001.jpg out.png) - No differences, as you say.
And here (ffmpeg -i out001.jpg -qscale 2 out.avi) begins a ... gm ...
magic ))
When I play out.avi with mplayer2 (http://www.mplayer2.org/), there is
difference between jpg and avi (avi is less contrast), but when I play
out.avi with KMplayer, there is no contrast differences... Only little
white balance, but it is not so important.
So. I don't understand, maybe it is mlayer2 bug, or ffmpeg bug but not in
that place that I thought. (Because mplayer2 use the same ffmpeg for
decoding video).
I attached a screenshot with two opened mplayer2 windows (left - input
file with normal contrast, right - output file with low contrast), seems
like on this screenshot contrast differences looks good. (If not, you can
in gimp test a color value in same white places on image, and see the
difference).
But I still cannot understand, why when i use yuv4mpeg raw file for
encoding there is no contrast differences in mplayer2.
About compiler options, I not test it so deep, I do this later, and maybe
you can recommend what test I can perform to be sure is that options
efficient or not.
--
Ticket URL: <https://avcodec.org/trac/ffmpeg/ticket/225#comment:6>
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