[MPlayer-users] A/V sync problem when appending AVIs

[D Richard Felker III]

On Fri, Feb 06, 2004 at 09:18:22AM +0100, Daniele Forghieri wrote:
> Matthias Czapla wrote:
> 
> >Hello!
> >
> >I have created three AVI files with (for each one)
> >
> >mencoder -aid 128 -srate 44100 -oac mp3lame -lameopts cbr:br=112:aq=2 \
> >-ovc frameno -o frameno.avi -dvd-device some_image.bin dvd://1
> >for i in 1 2; do
> >	mencoder -oac copy -ovc lavc \
> >       -lavcopts vcodec=mpeg4:mbd=2:trell:vbitrate=509:vpass=$i \
> >	-sws 2 -vf crop=672:316:24:130,scale=544:240 \
> >	-dvd-device some_image.bin dvd://1
> >done
> >
> >Each one plays fine as usual, but when appending them via
> >
> >cat 1.avi 2.avi 3.avi | mencoder -noidx -oac copy -ovc copy -o bla.avi -
> >
> >I get A/V desyncronized after the point where the second file starts. 
> >Before
> >that point theres no problem. I already tried to append them with avidemux
> >but this produced exactly the same result (i.e. A/V desync). I have often
> >done this before without any problems but this time it strikes me.
> >
> >Regards
> >Matthias
> >
> >_______________________________________________
> >MPlayer-users mailing list
> >MPlayer-users at mplayerhq.hu
> >http://mplayerhq.hu/mailman/listinfo/mplayer-users
> >
> > 
> >
> mp3 uses packet of sound of, say, 250 millisec.

Nope, mp3 packet size is basically irrelevant unless you have lots of
files. It's about 1/40 of a second, i.e. 25 ms. The problem is more
likely that the source files just have wrong-length audio.

Rich