[FFmpeg-user] Help: transform 'asyncts=first_pts=0' into new 'aresample' filter

Frank Häfemeier ffmpeg at frank.haefemeier.eu
Sun Feb 3 01:12:09 CET 2013


Am Samstag, den 02.02.2013, 23:01 +0000 schrieb Carl Eugen Hoyos:
> Frank Häfemeier <ffmpeg <at> frank.haefemeier.eu> writes:
> 
> > The sample itself is in sync, but after converting it into h.264/aac in
> > mp4 container the audio is out of sync. You can see and hear it if you
> > are around 20s when you see people talk.
> > As I currently understand, the first approx. 0.30s are the problem,
> > because I found out during my tests (to get the sample), if you skip the
> > first 0.40s or so (using -ss 00:00:00.40 after -i parameter) the audio
> > is in sync without using a filter.
> > 
> > 30s video sample:
> > http://www.datafilehost.com/download-c12482c8.html
> 
> I tested the following command lines:
> $ ffmpeg -async 1 -i video-sample.ts -qscale 2 out.avi
> $ ffmpeg -async 1 -i video-sample.ts -qscale 2 -vcodec mpeg4 -strict -2 out.mov
> 
> Both out.avi and out.mov play in-sync, both when encoded 
> with current FFmpeg and an older version.
What can I learn from your test?
> 
> Thank you for the sample, Carl Eugen
You are welcome.

-- Frank



More information about the ffmpeg-user mailing list