[FFmpeg-trac] #5181(undetermined:new): Video component range (mpeg/pc) not tracked properly between filters

[FFmpeg]

#5181: Video component range (mpeg/pc) not tracked properly between filters
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             Reporter:  Misaki        |                     Type:  defect
               Status:  new           |                 Priority:  normal
            Component:  undetermined  |                  Version:  2.7.3
             Keywords:                |               Blocked By:
             Blocking:                |  Reproduced by developer:  0
Analyzed by developer:  0             |
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 I apologize if some aspect of this report is done wrong.

  time nice ffmpeg -i "$in" $enc -vf
 trim=end_frame=1,scale=in_range=mpeg,format=yuv444p,crop=1890,showinfo,scale=1624:-1,showinfo,format=yuv420p,showinfo,crop=1600,showinfo
 -an -f null -

 input is yuvj420p (pc range). First scale leaves video unchanged. Second
 scale reduces the range, that is it assumes the video is pc range.
 (Possibly documented before regarding grayscale to yuv conversions for
 alphamerge, when input was yuvj?)


 same result, just more showinfos (and out_range=mpeg)

  time nice ffmpeg -i "$in" $enc -vf
 trim=end_frame=1,showinfo,scale=in_range=mpeg:out_range=mpeg,format=yuv444p,crop=1890,showinfo,scale=1624:-1,showinfo,format=yuv420p,showinfo,crop=1600,showinfo
 -an -f null -


 Fixed by using in_range=mpeg on second scale too.

 The relevant portions of -v 9 -loglevel 99:

 [Parsed_scale_2 @ 0xa26620] w:1920 h:1080 fmt:yuvj420p sar:0/1 -> w:1920
 h:1080 fmt:yuv444p sar:0/1 flags:0x4
 [...]
 [Parsed_scale_6 @ 0xa28900] w:1890 h:1080 fmt:yuv444p sar:0/1 -> w:1624
 h:928 fmt:yuv420p sar:0/1 flags:0x4

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Ticket URL: <https://trac.ffmpeg.org/ticket/5181>
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