[FFmpeg-trac] #8195(undetermined:new): v210 encoding clips to 4-1019

FFmpeg trac at avcodec.org
Tue Sep 24 06:50:10 EEST 2019

#8195: v210 encoding clips to 4-1019
             Reporter:  pdr0         |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
 ffmpeg v210 encoding clips to 4-1019

 You could argue, that for AV equipment , 10bit values <4 , >1019 are
 usually reserved for sync . But I don't think it should clip
 automatically, it should be up to the user.

 I've prepared a 1 frame v210 test clip with Y = "0" and "1023" patches .
 (The patches in the leftmost and rightmost columns)

 ffmpeg -i belle_nuit_mod_10bit422_vdub.avi -c:v v210 -an


 The output file clips the patches to "4" and "1019" instead
 (Pixel values were checked in vapoursynth editor)

 At the very least, there seems to be some inconsistent handling.

 If you encode that v210 clip to ,say DNxHR, the patches are decoded as 0,

 ffmpeg -i belle_nuit_mod_10bit422_vdub.avi -c:v dnxhd -profile:v dnxhr_hqx
 -an ffmpeg_v210_to_dnxhr.mxf

 But if you decode/convert that dnxhr hqx to v210, it becomes 4 and 1019 .

 ffmpeg -i ffmpeg_v210_to_dnxhr.mxf -c:v v210 -an

 In other programs, e.g. Adobe, Resolve - there is no clipping unless you
 tell it to

Ticket URL: <https://trac.ffmpeg.org/ticket/8195>
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