[MPlayer-users] Advice on solving out of sync movie

D Richard Felker III dalias at aerifal.cx
Sat Mar 15 05:06:27 CET 2003


On Fri, Mar 14, 2003 at 10:28:59PM -0300, romildo at uber.com.br wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> On Thu, Mar 13, 2003 at 04:33:20AM -0800, Corey Hickey wrote:
> > 
> > Jose Romildo Malaquias wrote:
> > >
> > >I am having problems with mencoder producing movies
> > >with good synchronization between audio and video.
> > >I am running mencoder 0.90rc4-3.2 on a Red Hat Linux 8.0
> > >box. I have also tried mencoder CVS-021210-03:00-3.2
> > >with similar results.
> > >
> > >I need advice on how to proceed to solve this
> > >problem (even if that envolves using other tools
> > >besides mencoder).
> > >
> > 
> > I and others have had this problem too, where the video is just barely
> > out of sync with the audio, by less than 100ms in most cases. Somebody
> > posted to this list a day or two ago about using -mc 0 to correct that.
> > I've tried a couple samples, and found that adding -mc 0 to the encoding
> > command fixed the sync with my DVD that used to produce the worst sync,
> > and screwed up another DVD that had good sync before.
> > 
> > I sort of think using -mc 0 is a bad idea, but I haven't heard from any
> > of the gurus around here yet. Arpi, Richard, or somebody, could you
> > please elaborate?
> 
> Adding -mc 0 to the encoding command had no effect.

For some reason you also need -noskip to make it work. It still is
probably a bad idea though...

> > In any case, for this and a couple other reasons I've started using
> > ogmmerge, of Moritz Bunkus' Excellent OGMtools (TM) :-) to create ogm
> > files out of video encoded by mencoder and ogg vorbis audio. I haven't
> > seen any sync problems with that process yet.
> > http://www.bunkus.org/videotools/ogmtools/
> 
> I have tried the steps sugested in the ogmtools README file and
> created an ogm file out of the video encoded by mencoder. The
> out of sync persists in the ogm file.
> 
> I have done experiments withe mencoder, and found out that
> the out of sync is happening only with 3 passes encoding.
> With 2 passes and 1 pass encoding, I have obtained
> good avi files, without the problem. Maybe the
> developers should investigate what is going on wrong
> with the 3 pass encoding code.

Hmm. For now just use 2pass with -oac copy or -oac pcm -o /dev/null on
pass 1, then the real options on pass 2...

I agree this should be fixed though.

Rich



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