[FFmpeg-trac] #351(undetermined:open): ffv1 frames are not marked as keyframes in mkv

[FFmpeg]

#351: ffv1 frames are not marked as keyframes in mkv
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Reporter:  dericed                        |       Owner:
    Type:  defect                         |      Status:  open
Priority:  normal                         |   Component:  undetermined
 Version:  unspecified                    |  Resolution:
Keywords:  ffv1 mkv matroska mkvalidator  |  Blocked By:
Blocking:                                 |  Reproduced:  0
Analyzed:  0                              |
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Comment (by dericed):

 Replying to [comment:5 reimar]:
 > > aren't all ffv1 frames keyframes
 >
 > No, they depend on the arithmetic coding state of previous frames unless
 you use -g 1.
 > The matroska encoder opens a new cluster at the latest after 5 MB of
 data. Since your ffv1 frames are very large it can't do that without
 creating some clusters without keyframes.
 > This could probably be improved/made configurable in the muxer, but
 those are only warnings after all.

 Thanks for the explanation of the 5MB limit. For now, I'll looking into
 using '-g 1' or 'mkclean --remux' on the result.

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Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/351#comment:6>
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