[MPlayer-dev-eng] New inverse-telecine filter

[Zoltan Hidvegi]

> On Tue, Dec 02, 2003 at 10:10:08AM -0600, Zoltan Hidvegi wrote:
> > +.IPs luma_only=n
> > +If n is nonzero, the chroma plane is copied unchanged.  This is useful
> > +for YV12 sampled TV, which discards one of the chroma fields.
> 
> This description is somewhat incorrect. Well-formed interlaced YV12
> never discards chroma fields. Only broken TV card drivers, which
> misreport that they support YV12 when in fact they actually don't, do
> this. A more appropriate description would be "bug workaround for
> bttv's brain damage". :)

The problem is that no TV can can properly support NTSC -> YV12
conversion, because such a conversion would have to know if a frame is
progressive or interlaced.  For a progressive frame, a simple scaling
of the chroma plane works, but for interlaced, you have to do
interlaced scaling.  The bug is really in mplayer not supporting 411
TV capture (or 422, but NTSC is really just 411).  I guess you can do
uyvy or yuy2 (what is yuy2, I always confuse this stuff), but I did
not have much luck with that, since it's packed.  bttv supports 411p
and 422p, but mplayer cannot use that for some reason.

Zoli