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

[Rich Felker]

On Wed, Sep 14, 2005 at 07:15:31PM +0200, Matthias Wieser wrote:
> 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.

Well audiophiles seem to hear the difference between a digital signal
carried over $5 copper and a digital signal carried over $20000 solid
gold speaker cables... :P

> > > > 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.

A video camera does not do pulldown. It generates _VIDEO_, which is
interlaced...

Rich