[MEncoder-users] Extra audio (dubbing) out of sync with video

[Tomasz Ksiezyk]

I have ripped a movie with 2 passes:

mencoder dvd://<title-number> -dvd-device <video-ts-dir> -oac copy -vf 
crop=720:448:0:14 -ovc lavc -lavcopts 
vcodec=mpeg4:vbitrate=1000:v4mv:mbd=2:trell:cmp=3:subcmp=3:mbcmp=3:autoaspect:vpass=1 
-o /dev/null -aid 128

mencoder dvd://<title-number> -dvd-device <video-ts-dir> -oac copy -vf 
crop=720:448:0:14 -ovc lavc -lavcopts 
vcodec=mpeg4:vbitrate=1000:v4mv:mbd=2:trell:cmp=3:subcmp=3:mbcmp=3:autoaspect:vpass=2 
-o <film-name>.avi -aid 128

which went fine. In particular, the audio and the video were in perfect 
sync.

Then, I extracted the dubbing audio for this film with:

mencoder dvd://<title-number> -dvd-device <video-ts-dir> -oac copy -ovc 
copy -o temp.avi -aid 132
mplayer -quiet -vo null -ao pcm -ao pcm:file=audio.wav temp.avi
lame --silent audio.wav dubbing.mp3

When I played the movie with the option:

-audiofile dubbing.mp3

the dubbing audio was out of sync with the video. The discrepancy was 
getting bigger with time: at minute 106 the audio was 6 sec ahead of the 
video.

When I have ripped the movie again using the 2 passes as above, but 
setting the value of -aid to 132 (dubbing channel), the result was fine 
again: the dubbing audio was in sync with the video.

Reimar Döffinger suggested to use the options -mc 0 -noskip when ripping 
the video. Unfortunately, when I followed his advise, only a fraction of 
the film got ripped: out of the 128 minutes I got only the first 23 minutes.

Could somebody explain this behavior and suggest a solution to my problem.

Thanks,

Tomasz Ksiezyk