[FFmpeg-trac] #911(undetermined:closed): ffplay can't handle timecodes of WMV2 video correctly
FFmpeg
trac at avcodec.org
Thu Jan 12 00:14:33 CET 2012
#911: ffplay can't handle timecodes of WMV2 video correctly
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Reporter: | Owner:
zhushisongzhu | Status: closed
Type: defect | Component:
Priority: important | undetermined
Version: git-master | Resolution:
Keywords: asf wmv2 | worksforme
seeking | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
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Comment (by cehoyos):
Let me try it differently:
For most videos, media players can only seek to keyframes ("I-frames"),
they cannot seek to non-keyframes (all other frames), if they seem to
allow to seek to non-keyframes, they do it by seeking further back and not
displaying the frames in-between (this can be different for H264, but your
sample is WMV2). The behaviour of not showing some frames can lead to a
kind of freeze while the user is waiting for the frame with the specified
timestamp, this is typically not intended behaviour and ffplay does not
support this.
Your sample contains two such I-frames (keyframes), one at the beginning,
one after ten seconds, you can find out yourself with mplayer hzvideo.wmv
-lavdopts skipframe=nonkey
ffplay -ss 1 until -ss 9 seeks to the last keyframe that comes before the
specified timestamp, that is the first frame for your sample, ffplay -ss
10 and above seeks to the second keyframe of the video.
Is that more understandable?
--
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/911#comment:4>
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