[MEncoder-users] Audio Sync issues

[Bill Crockett]

> It's a lot closer, though the audio seems to be leading the video by a
> small, but progressively increasing amount.
>
> Here's the revised command:
> mencoder infile.mpg -noodml -ffourcc XVID -vf
> scale=720:480,tinterlace=4,filmdint=io=30:24/fast=0 -aspect 16:9 -ovc lavc
> -lavcopts
> vcodec=mpeg4:threads=8:vbitrate=4000:cmp=2:subcmp=2:trell=yes:v4mv=yes:mbd=2
> :/aspect=16/9:top=0 -oac pcm -channels 2 -noskip -fps 60000/1001 -ofps
> /24000/1001 -o outfile.avi
>
> This may be related to Andrew's earlier suggested solution.  I'm going to
> re-add the -vf harddup option and see if that cures the remaining sync
> issues.
>
> -----------------
>
> One difference I notice is that you start out with an mpeg container. I have
> always used the transport stream container (.TS) which might be something to
> try. I doubt that the harddup will make a lot of difference.
>
> One thing I notice is that you are converting to PCM. Any particular reason
> why you are keeping the original audio? You are certainly not getting a
> quality boost here - just a bigger file. The PVR captures either in AAC or
> AC3, both lossy formats and doing an -oac copy will give you a smaller file
> with equal quality. But maybe this is a limitation of your playback device?
> ------------------------------------------------------------------------

About the -noskip option:  maximum A-V sync correction per frame (in 
seconds) -mc 0 should always be combined with -noskip for mencoder, 
otherwise it will almost certainly cause A-V desync.  I don't know if 
that will help.  All you can do is try it.

Bill