[FFmpeg-trac] #5704(avformat:new): Wrong timestamps muxing theora into ogg when theora decoder is disabled

[FFmpeg]

#5704: Wrong timestamps muxing theora into ogg when theora decoder is disabled
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             Reporter:  jamrial     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by jamrial):

 This technically would also happen with other video codecs muxed into Ogg,
 like VP8 and Daala, since all of them store timestamps using the least
 common multiple framerate, where pts increases by 1 per frame.
 Based on that, fixing this moving the relevant code from the Theora
 decoder to the parser, assuming it's possible, wouldn't solve the core
 issue of the muxer allowing any kind of timestamp and time base.

 One solution could be using the lowest common multiple framerate if it
 differs from st->time_base, then rebase all the timestamps as the frames
 are muxed.
 For Theora (and in the future Daala) this is as simple as using the time
 base reported by the stream header in st->codecpar->extradata, but for
 other codecs using st->r_frame_rate or similar will be necessary.

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Ticket URL: <https://trac.ffmpeg.org/ticket/5704#comment:1>
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