[MPlayer-users] introducing DVD-to-DivX approach that fixes A/V sync problems

[Rich Felker]

On Wed, Jul 06, 2005 at 11:10:58AM -0400, Giacomo Comes wrote:
> On Tue, Jul 05, 2005 at 01:34:31PM -0400, Rich Felker wrote:
> > On Sun, Jul 03, 2005 at 11:16:45PM +0100, Martin Collins wrote:
> > > On Sun, 3 Jul 2005 19:35:00 +0200
> > > Joachim Jautz <lists.mplayer-users at jay-jay.net> wrote:
> > > 
> > > > when converting a DVD into DivX using MEncoder it can (under
> > > > certain circumstances) happen that the resulting movie's audio and
> > > > video are out of sync. Usually the delay is about 300ms which is
> > > > enough to be annoying.
> > > 
> > > Isn't the main reason for this that you are using abr which avi can't
> > > handle very well?
> > 
> > No, this is a lie perpetuated by authors of stupid windows software.
> > VBR is the natural audio format for avi and always has been.
> > 
> > > Using cbr should fix this. Or use the matroska
> > > container instead of avi.
> > 
> > No. The a/v sync problems with vbr audio are caused by a bug in
> > mencoder combined with lame's excessive prebuffering of audio when
> > encoding vbr. It has nothing to do with avi container.
> 
> Is there any trick that can be used to avoid a/v sync problems 
> with vbr audio using mencoder (mencoder or lame options)?

Yes, several.

1. Encode with -oac copy or -oac pcm, then once you have your
   almost-final file, reencode it with -mc 0 -noskip -oac mp3lame -ovc
   copy. I _think_ this will work, but not sure.

2. Dump the audio with mplayer -ao pcm and encode it with external
   lame. Then run mencoder with -audiofile lame_output.mp3 -oac copy.

3. ??

IMO there are others but I can't think of them right now. I always use
#2 and it works very well.

Rich