[FFmpeg-trac] #7476(undetermined:new): Invalid pts and duration generated for mp4 when converting from webm
FFmpeg
trac at avcodec.org
Mon Oct 8 12:07:26 EEST 2018
#7476: Invalid pts and duration generated for mp4 when converting from webm
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Reporter: jyavenard | Owner:
Type: defect | Status: new
Priority: normal | Component:
Version: unspecified | undetermined
Keywords: | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
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Comment (by Gyan):
WebM files, especially when geenerated via WebRTC, often show the
reciprocal of the timebase as their framerate. The timebase for
Matroska/WebM files is 1/1000.
The MP4 muxer defaults to constant frame rate, so with your first command,
ffmpeg will duplicate frames to achieve a 1000 fps output. In this output,
each frame will obviously have duration 1/1000 s.
Use
`ffmpeg -i MozilleTest -vsync 0 -c:v libx264 test.mp4`
to preserve original timestamps with no frame duplication. The resulting
file will have an avg rate of 30.04.
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Ticket URL: <https://trac.ffmpeg.org/ticket/7476#comment:2>
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