[MPlayer-users] Audio Lag and Index Problem

[ras2]

On 2003-01-19 at 00:57:18 -0500, Oliver Strutynski <olistrut at gmx.net> wrote:
> 
> With a full three-pass encoding the sound is totally off - delay is more than 
> five seconds after the first few minutes and several scenes at the end of the 
> movie. Here are the commands I used:
[...] 
> mencoder -dvd 1 -alang en -o test1.avi -oac mp3lame -lameopts vbr=3:vol=8 \
> - -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1527:vhq:vqmin=2:keyint=10:vpass=2 \
> vlelim=-4:vcelim=9:lumi_mask=0.05:dark_mask=0.01  -vop \
> scale=720:336,crop=710:350:8:64 -ofps 23.976 -zoom -aspect 4:3
> 
> Anything wrong here?

If you have duplicated video frames, you will get audio desync if you
use -ofps when you encode; when you captured/copied/whatever the original
file, extra video frames were inserted to keep the audio in sync, so if
you then try to re-encode the file with correct FPS value, the audio will
lag.
 
> I noticed that mencoder showed far less "duplicate frame" messages (just 2
> and some skipped frames) when using the three-pass method.

Not surprising. That should also be the case with a single pass with
-ofps.


-R.