[MEncoder-users] Audio sync problem

[Reimar Döffinger]

On Thu, Sep 10, 2009 at 04:21:36PM +0100, Owen Williams wrote:
> On Wed, 2009-09-09 at 23:15 +0200, Reimar Döffinger wrote:
> > On Wed, Sep 09, 2009 at 03:07:10PM +0100, Owen Williams wrote:
> > > On Wed, 2009-09-09 at 14:33 +0200, belcampo wrote:
> > > > > Freeview can/will have multiple aspect ratios in the recording so no
> > > > > matter what which format I'd like to have the picture centered in
> > > > the
> > > > > image with appropriate black borders for that aspect ratio at that
> > > > > moment in the stream.
> > > > I don't think that is possible. AFAIK all encoders detect aspect
> > > > ratio 
> > > > and use that from start till end. If you want 4:3 in 16:9 aspect
> > > > you'll 
> > > > have to add blackborders explicitely.
> > > 
> > > I thought I had the magic right but this is the result after subsequent
> > > aspect ratio changes (for each advert in the film:
> > > 
> > > http://ocean.blue.dmu.ac.uk/~williams/Film4/01.jpg
> > > http://ocean.blue.dmu.ac.uk/~williams/Film4/02.jpg
> > 
> > Please someone try attached patch.
> 
> That worked beautifully.  Correct borders and centred correctly.  I'm
> just running it again against:
> 
> -vf yadif,expand=::0:0::4/3,scale=640:480,harddup",

Good, patch applied.
Note that for improved readability I'd suggest that instead of
expand=::0:0::4/3
you use the equivalent
expand=aspect=4/3