Re: transcode filters

On Wed, Apr 21, 2004 at 12:16:16PM +0400, Vladimir Mosgalin wrote:
> On Tue, 20 Apr 2004, D Richard Felker III wrote:
> 
> DRFI>> > > > > decimate - NTSC decimation in pure software
> DRFI>> > > > 
> DRFI>> > > > What is NTSC decimation?
> DRFI>> > > 
> DRFI>> > > Removal of duplicate frames. Made as a part of the inverse telecine
> DRFI>> > > process. MPlayer seems to have the whole process in one big whopping
> DRFI>
> DRFI>Inverse telecine does not naturally make duplicate frames. We didn't
> DRFI>"hide" the decimation process inside the inverse telecine filters;
> DRFI>it's simply not happening.
> DRFI>
> DRFI>> > > filter (ivtc or detc); but heck, what if I need this stuff for other
> DRFI>> > > purposes? 
> DRFI>> > 
> DRFI>> > there is such filter for duplicate (very similar) frame removal
> DRFI>> 
> DRFI>> I have not found it, but it's probably just me.
> DRFI>
> DRFI>It's called *gasp* decimate!
> 
> You are a little wrong here. Sure, since you never tried those filters
> in transcode you might think so, but the following sequence of filters
> -J ivtc,32detect=force_mode=3,decimate
> 
> in transcode has no working alternative in mplayer. I tried a lot, but

What is this sequence supposed to do?

> found nothing. decimate filter in mplayer is different, that's all. I

What does transcode's decimate filter do? Drop 1 in 5 frames, picking
the one with the least difference? The new divtc filter in mplayer
(silly name, oh well) does that.

> Yes, ivtc filters in mplayer are overally better. But _there are_ cases
> when transcode gives desired result and mplayer doesn't.

If you have example clips where the various filters mess up, I'd
appreciate seeing them.

> smartdeint is another very good ported from vdub filter (that's why it
> is working in rgb, and smartyuv was made afterwards as "special yuv
> version for transcode") that imho is the best deinterlacer. It's a shame
> it isn't present in mplayer, but I haven't looked at kerndeint yet. I
> hope it is just ported smartdeint with stupid name, not something
> written from scratch...

I think it's the same thing. I tried it on telecined content because I
didn't have any true interlaced material handy, and I must say I
wasn't impressed. The kernel it uses for deinterlacing the interlaced
parts is bad (produces nasty edge-ghosts) and it deinterlaces wherever
there's motion, rather than just the areas that have combing.

Rich