[MPlayer-dev-eng] New inverse-telecine filter
vektor at dumbterm.net
Thu Dec 4 19:41:56 CET 2003
Zoltan Hidvegi (mplayer at hzoli.2y.net):
> > > The bug is really in mplayer not supporting 411 TV capture (or
> > > 422, but NTSC is really just 411).
> > Why do you say that NTSC is just 4:1:1 ?
> NTSC have the same vertical chroma resolution as luma, but one quarter
> of the horizontal resolution, that's why I say that NTSC is 422, while
> YV12 is 420.
You said NTSC is 4:1:1, why? Studio NTSC is always stored and
transmitted as 4:2:2 (half the horizontal resolution for chroma, same
vertical resolution). The only 4:1:1 storage and transmission format in
common use that I know of is DV.
> Much of the content on TV is originally progressive, broken up to
> interlaced fields, such as telecined movies or video from a 30fps
> progressive camera.
I would say that most is true interlaced content, or at least more
than you imply (TLC, CNN, Comedy, any Sports broadcasts, ...).
> For such content the progressive content should be reconstructed, and
> normal progressive scaling should be used to get yv12. But if you
> have hard interlaced content, you have to do interlaced scaling. The
> TV card cannot figure this all out, the only right thing to do is to
> capture in 422 and do some de-interlacing before the yv12 conversion.
If you are intending to convert to YV12 I would agree with you:
capture in 4:2:2 and do all processing before converting to any 4:2:0
format, and indicate in your output whether the YV12 frame is interlaced
or progressive (like the progressive_frame flag in MPEG2). Similarly,
if you're just watching TV, keep it in 4:2:2 right to the display.
That's what I do in tvtime.
But if youre capturing in YV12, then it's a bug in bttv if it does not
give interlaced chroma, there is no way around that.
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