[FFmpeg-user] Comments about audio sync invited

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Jul 9 14:00:45 CEST 2013

James Linder <jam <at> tigger.ws> writes:

> ffmpeg version 1.0.6

This is old, please update to current git head.

> Input #0, pulse, from 'default':
>   Duration: N/A, start: 0.636342, bitrate: 1536 kb/s

> Input #1, video4linux2,v4l2, from '/dev/video0':
>   Duration: N/A, start: 1373359581.412447, bitrate: 23040 kb/s

> [avi at 0x6ae480] st:0 PTS: 352982 DTS: 
> 352982 < 353004 invalid, clipping

These are the culprits (note the different start 
times apart from the warning).

Please try -use_wallclock_as_timestamps (it is 
possible that this only works with alsa).


> > is the problem also reproducible with ffmpeg 
> > alone (without the pipe to ffplay)?
> Hmmm without the ffplay display all looks good.

Maybe somebody who knows more about pipes can comment.

> I watch cpu usage at 50% odd.

What happens if you significantly reduce the load by 
using a much smaller resolution?

Carl Eugen

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