[MPlayer-users] Re: [-] Re: slightly confused by mencoder output

[Matthias Wieser]

Am Mittwoch, 14. September 2005 18:22 schrieb Rich Felker:
> On Wed, Sep 14, 2005 at 10:58:30AM +0200, Matthias Wieser wrote:
> > > NTSC just happens to be 3:2, whereas PAL is 2:2
> >
> > That's the reason I wrote "but sometimes it would be better to use
> > ivtc" [for NTSC].
> > I wrote "sometimes" because not every broadcast your TV Card receives
> > is a film with 3:2 pulldown.
> >
> > The disadvantage of ntsc is that you nearly always need to process
> > the video. For PAL you only have to use a deinterlacer if it's not
> > film content.
>
> This is exactly what I was saying is false. PAL can be
> 2:2:2:2:2:2:2:2:2:2:2:3 pulldown, or sometimes even field-blended to 
> convert from 24 fps to 50 field/sec. You're right that fairly often
> you get lucky and it's just sped up with 2:2 pulldown, but it has
> nothing to do with relative advantage/disadvantage of PAL versus NTSC.

The 
>
> > > (with horrible speed-up)
> >
> > That's a bit esoteric because there are filters which are able to
> > speed up the audio without changing the pitch.
>
> However this invariably damages the audio quality.

Maybe my dog or my cat will hear the distortions caused by 4% speedup. I 
don't hear a difference when I use a xmms plugin to speed up sound by 4%. 
And broadcasting studios probably have even higher quality equippment.

> > > or 2:2:2:2:2:2:2:2:2:2:2:3. :) Also there's no guarantee
> > > that 2:2 PAL is in phase with the field pairing of the capture
> > > device.
> >
> > There is no formal guarantee but it works for 99,...% of all cases.
> > To be precise: I have never had any captured video which was out of
> > phase. Oh,
>
> It's been reported on the list fairly often, and was important enough
> that someone even made a filter for it..

I think, those were caused by buggy kernel modules or video cameras.