[MPlayer-users] mkv to divx audio sync issues

[Nico Sabbi]

Il Saturday 24 November 2007 12:25:17 Bart de Boer ha scritto:
> Dear mplayer people,
>
> Sorry if I'm double-posting. I think something went wrong with my
> previous post. So here I go (again):
>
> I have a P4 2.8Ghz Celeron that isn't powerful enough to decode my
> 720p H.264 mkv's. So I'm using mencoder to convert them to MPEG4
> Divx. This works nicely performancewise. They only take up around
> 30% CPU to decode on that machine now. :)
>
> I am however having another issue. There always seems to be a
> slight A/V sync problem. (The original mkv's run perfectly in
> sync.) I tried different mkv's. I also tried numerous parameters
> without success. One thing that seemed to work (in most cases) is
> to seek 1 second into the video using -ss 0:00:01 and start
> converting from there. Therefore I conclude something goes wrong at
> the beginning few frames of the video.
>
> These are the commands I'm currently using:
>
> mencoder ${inputFile} -ss 0:00:01 -oac copy -nosound -mc 0 -noskip
> -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=4000:turbo:vpass=1
> -passlogfile ${logFile} -o /dev/null
>
> mencoder ${inputFile} -ss 0:00:01 -oac copy -mc 0 -noskip -ovc lavc
> -lavcopts vcodec=mpeg4:mbd=2:trell:v4mv:vbitrate=4000:vpass=2
> -passlogfile ${logFile} -o $outputFile
>
> Is this an issue with mencoder or am I using the wrong method?
>

copying one or more of the streams with -mc 0 -noskip is generally
a recipe for disaster. remove -mc 0 -noskip and try also -demuxer lavf