[MPlayer-users] A-V getting out of sync on external audio stream

Jan Knutar jknutar at nic.fi
Sat Jan 31 16:06:30 CET 2004

> way :)).  So I dumped the stream from dvd (-ao pcm) encoded it with
> lame (lame -h) and when I try to play it (with -audiofile option of
> mplayer) the a/v gradually gets out of sync (at the beginning of the
> movie there is 0 delay and at the end - after about an hour - it gets
> up to 3s so it is really unacceptable).

Despite what I said in another thread, I've also seen something like 

Except, that I dumped it to pcm with -ao pcm, then ran oggenc on it. 
Playing back the avi (which has -ovc copy'd audiotrack from dvd), with 
-audiofile aid128.ogg, mplayer plays back the video as fast as it can 
without dropping frames, seemingly totally ignoring audio sync and fps.

Using CVS as of a few days old...

Steps to reproduce:

DVD with multiple sound tracks.

$ mencoder dvd://1 -aid 128 -oac copy -ovc lavc -o movie.avi -lavcopts\ 
<insert your favourites>

$ mplayer dvd://1 -vc dummy -vo null -aid 129 -ao pcm
$ oggenc audiodump.wav
$ mplayer -audiofile audiodump.ogg movie.avi

=> mplayer ignores fps and audio sync, playing back video as fast as the 
computer can.
A-V in status line starts rolling to negative values, afaics, they 
accurately display how much audio and video are out of sync.

-mc 0, -autosync 0, -autosync 1, -autosync 10 and combinations have no 
apparent effect.

-mc 10 makes the video jerky, and the A-V doesn't fly out of sync as 
fast anymore, only about 1 second per second audio played :-)

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