[FFmpeg-trac] #11182(undetermined:closed): testyuvsrc and yuv444p->rgba->yuv444p conversion result in huge difference

[FFmpeg]

#11182: testyuvsrc and yuv444p->rgba->yuv444p conversion result in huge difference
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             Reporter:  Andrew-R     |                    Owner:  (none)
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  unspecified  |               Resolution:  invalid
             Keywords:  colorspace   |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by Andrew-R):

 I was going for full range testing due to our (?) bug:

 https://www.cinelerra-gg.org/bugtracker/view.php?id=665

 I do not think we want to integrate zscale yet (I tried to do this some
 times ago and got crashes).

 For some reason with git ffmpeg I need to set
 /dev/shm/ffmpeg/ffmpeg -f lavfi -color_range 1 -i yuvtestsrc -frames 1 -r
 25 -vf scale=in_range=pc:out_range=tv -color_range 1 /dev/shm/yuv-mpeg-
 yuv444p.y4m -debug log

 in_range/out_range, not in_color_range/out_color_range.

 If I understand correctly swscale also doing internal rgb transfer if we
 try to change range on yuv data, so may be it exaggregates our problem
 when we exactly try to avoid yuv->rgba->yuv change by using yuva8
 internally ...
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Ticket URL: <https://trac.ffmpeg.org/ticket/11182#comment:4>
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