[MPlayer-dev-eng] Re: [RFC] change lacv's MPEG-4 encoding options defaults

[Michael Niedermayer]

Hi

On Thu, Dec 29, 2005 at 07:23:21PM +0100, Alexander Strasser wrote:
> [...]
> > >>>The default number of b-frames for x264 is currently 0 while most
> > >>>people use 2/3 as standard. Fair enough b-frames stored in avi aren't
> > >>>perfect, but standalones can play the produced files, most if not all
> > >>>software can play the produced files, so is this a real problem?
> > >>>     
> > >>Like I said: mencoder is broken so B frames cause a/v desync!!
> > >
> > >??
> > >That's only true under some circumstances. Normally mencoder + bframes 
> > >works very well. Additionally B-frames have been recommended for the 
> > >doom9 codec comparison. I don't think Corey made this to make mencoder 
> > >look bad :-)
> > 
> > depends on how many b-frames you use: in mpeg4 tipically only up to 2 
> > are used,
> > but in h264 people seem to even 5 and more.
> > The more there are the more audio and video will desync.
> 
>   Also note that there probably wasn't much need for a/v-sync at
> doom9's video codec comparison...

do i missunderstand something or wouldnt simply delaying the audio by
(1+b_frames)/fps or so fix the whole AV-sync issue with mencoder?
and yeah sure iam aware that b frames in avi are fundamentally wrong
and in mpeg-ps/ts which doesnt have pts per frame either they are less wrong

[...]
-- 
Michael