[MPlayer-users] deinterlace+horiz scale

[D Richard Felker III]

On Sat, Jun 05, 2004 at 09:42:17PM -0700, rcooley wrote:
> On Sat, 5 Jun 2004 14:13:44 -0400
> D Richard Felker III <dalias at aerifal.cx> wrote:
> 
> > And it also has ghosts whenever there was motion!! VERY VERY BAD!!
> > (Same thing as pp=lb :) 
> 
> Blur isn't good, but I think you over-state it.  With deinterlacers, I
> use pp=lb because it's the only one that doesn't produce
> terrible-looking output.  pp=md looks bad on most material, and
> absolutely terrible on high-contrast material like animation, on-screen
> text, etc.
> 
> I guess I should go try this on some animation to see what artifacts
> I can pick-out...
> 
> > It's especially bad if your video happens to
> > be telecined rather than 50/60 fps interlaced, since the ghosts will
> > flicker in and out and be 2.5x as large when they do appear.
> 
> Hmm.  I don't understand why they would be 2.5X as large.

Because frames are 1/24 sec apart instead of 1/60 sec.

> Anyhow,
> wouldn't adding -vf ivtc take care of that?

Yes but some people stupidly deinterlace telecined material, e.g. if
it's mixed in with interlaced.

> 
> > No, it's a "bug" in the brains of the idiot engineers who designed
> > interlacing. Interlacing is inherently flawed because both fields are
> > undersampled (and thus they alias) 
> 
> Well, it's just that I would have thought that -vf field would have done
> a bit more to improve the quality...

Huh? vf_field does exactly what it's name suggests: EXTRACT ONE FIELD.
It doesn't modify it at all. It uses 0% cpu. If you want to perform
modifications on it, write a separate filter.

Rich