[MPlayer-users] Conversion from avi to mpeg2 summary

[Giacomo Comes]

On Mon, Jun 27, 2005 at 12:17:22PM -0400, Rich Felker wrote:
> On Mon, Jun 27, 2005 at 05:23:31PM +0200, Guillaume POIRIER wrote:
> > Hej,
> > 
> > On 6/27/05, Giacomo Comes <comes at naic.edu> wrote:
> > > On Mon, Jun 27, 2005 at 03:09:12PM +0200, Nico Sabbi wrote:
> > > > Guillaume POIRIER wrote:
> > [...]
> > > > format=xsvcd.
> > > > In order to make the gop structure svcd compliant the keyint should be
> > > > 15 for pal and 18 for ntsc, although very often much longer gops play
> > > > correctly
> > > > (I always used 25 without problems).
> > > > Please, mention also that the resulting file
> > > > - is an extended svcd (that's why it's called xsvcd), mainly because it
> > > > doesn't
> > > > contain scan offsets
> > > > - it should be passed to vcdimager to generate the svcd image
> > > >
> > > 
> > > There should be a mention that PAL requires -ofps 25 and NTSC -ofps 30000/1001.
> > 
> > Fixed
> > 
> > 
> > > It it also necessary very often -vf harddup.
> > 
> > Is it safe to add it all the time?
> 
> Yes, and it should ALWAYS be used.

I forgot to mention in the previous mail that for (PAL) SVCD the resolution must
be 480x576 or 352x288. If the source video has a different resolution
then you must use -vf scale=480:576,harddup or -vf scale=352:288,harddup
(NTSC numbers are 480x480 and 352x240)

> 
> > > Question. Is -af lavcresample=44100 necessary? My experience shows that just -srate 44100
> > > is enough (althouth I always use it with -af-adv force=1).
> > 
> > I don't know, I've never tested it. What's the advantage of your
> > command line (with -af-adv force =1 on)? Better quality?
> 
> Isn't force=1 the default?? IMO -srate 44100 should be enough.
> If it's not default, can we change it?

No it isn't. force=2 is the default. And I have samples 
where the resampling introduces a distortion if I don't use force=1

I vote for force=1 as default.

Giacomo