[FFmpeg-trac] #5548(avcodec:open): FFV1 encoder creates invalid stream with -level 3 if width or height is between 1 and 3 (was: FFV1 encoder creates invalid stream with -level 3 if width or height is 1 or 2)

[FFmpeg]

#5548: FFV1 encoder creates invalid stream with -level 3 if width or height is
between 1 and 3
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             Reporter:  Zenitram    |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  FFV1        |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |
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Comment (by Zenitram):

 I slightly change the report:
 - with width or height of 1, there is no valid slice so there is an error
 from FFmpeg during decode
 - with width or height of 2 or 3, the last slice (horizontal or vertical)
 is invalid so discarded and the first slice is the only one decoded.

 with:
 - ffmpeg -y -f lavfi -i "color=c=white" -t 10 -filter:v scale="3:3"
 -vcodec ffv1 -level 3 3x3.mkv then playback in e.g. VLC it is yellow on
 the top left and black right and bottom.
 - ffmpeg -y -f lavfi -i "color=c=white" -t 10 -filter:v scale="4:4"
 -vcodec ffv1 -level 3 4x4.mkv then playback in e.g. VLC it is white
 everywhere.

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Ticket URL: <https://trac.ffmpeg.org/ticket/5548#comment:2>
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