[Ffmpeg-devel] avi out is buggy

Michael Niedermayer michaelni
Mon May 9 12:25:07 CEST 2005


On Monday 09 May 2005 12:08, Thomas Herrmann wrote:
> Hi,
> it seems the avi output of ffmpeg is buggy in the way that AC3 sound gets
> out of sync over time. The sound just drifts apart from the video. This is
> true too with AAC coded sound, while MP2 seems to be fine.
> To reproduce this I take a MPEG sample containing a MPEG2 video stream and
> an AC3 audio stream and do:
> ffmpeg -i sample_w_ac3.mpg -vcodec copy -acodec copy out.avi
> While playing this file with mplayer, the sound starts in time with the
> video, but drifts away quickly.

stream copy from mpeg to avi isnt synchronizable, mpeg has timestamps, avi 
does not, so frame drop / audio resampling might be needed but its not 
possible with stream copy

-> bug closed / invalid



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