[MPlayer-users] Comparison of different deinterlace and denoise filters

D Richard Felker III dalias at aerifal.cx
Fri Oct 17 04:56:32 CEST 2003


On Thu, Oct 16, 2003 at 08:42:11PM +0200, Matthias Wieser wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Am Donnerstag, 16. Oktober 2003 20:12 schrieb D Richard Felker III:
> > > So is it right to say: If you have a bttv card, you have to record tv
> > > with "mencoder -tv outfmt=yuy2 -vf il=d:d,scale,format=yv12,il=i:i",
> > > but if you have a saa7134 card, you only need "mencoder -tv
> > > outfmt=yuy2"?
> >
> > No. All mpeg type codecs are 4:2:0 (aka yv12), so you must downsample
> > to 4:2:0 before encoding.
> 
> OK
> 
> > If you don't do it manually, then vf_scale
> > will get loaded automatically for format conversion, and it will
> > butcher the chroma planes (by blending the two fields).
> 
> That may be the case with a bttv card.
> But I see _no_ chroma errors when I record only with outfmt=yuy2.
> Maybe thats because of the saa7134 driver.

This is impossible by the nature of yuy2. It has 4:2:2 sampling. When
mencoder rescales the chroma to half height (4:2:0), it will be
ruined. Do you know what error you're looking for?

> > The only way to get around having to use
> > il=d:d,scale=format=vy12,il=i:i is if your card can natively capture
> > proper 4:2:0 video. (Unless you just want to capture at half-height to
> > begin with...)
> 
> Which cards can do that? 

Probably anything but bttv, as long as you leave the default outfmt
(yv12). However, you should check and make sure. Chroma plane should
be interlaced just like the luma.

Rich



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