[MPlayer-G2-dev] transcode filters

[Vladimir Mosgalin]

On Wed, 21 Apr 2004, D Richard Felker III wrote:

DRFI>> You are a little wrong here. Sure, since you never tried those filters
DRFI>> in transcode you might think so, but the following sequence of filters
DRFI>> -J ivtc,32detect=force_mode=3,decimate
DRFI>> 
DRFI>> in transcode has no working alternative in mplayer. I tried a lot, but
DRFI>What is this sequence supposed to do?

It's supposed to er.. remove telecine, I presume ;) It was a strange and
hard case, looked like material that was deinterlaced after telecine,
but not quite, and it was on dvd.

DRFI>> found nothing. decimate filter in mplayer is different, that's all. I
DRFI>
DRFI>What does transcode's decimate filter do? Drop 1 in 5 frames, picking
DRFI>the one with the least difference? The new divtc filter in mplayer

Yes.

DRFI>(silly name, oh well) does that.

Maybe, but it is _really_ new ;)

DRFI>> Yes, ivtc filters in mplayer are overally better. But _there are_ cases
DRFI>> when transcode gives desired result and mplayer doesn't.
DRFI>
DRFI>If you have example clips where the various filters mess up, I'd
DRFI>appreciate seeing them.

Sorry.. I have only slow modem connection, and uploading even parts of
dvd's is a hard thing to do.

DRFI>> smartdeint is another very good ported from vdub filter (that's why it
DRFI>> is working in rgb, and smartyuv was made afterwards as "special yuv
DRFI>> version for transcode") that imho is the best deinterlacer. It's a shame
DRFI>> it isn't present in mplayer, but I haven't looked at kerndeint yet. I
DRFI>> hope it is just ported smartdeint with stupid name, not something
DRFI>> written from scratch...
DRFI>
DRFI>I think it's the same thing. I tried it on telecined content because I
DRFI>didn't have any true interlaced material handy, and I must say I
DRFI>wasn't impressed. The kernel it uses for deinterlacing the interlaced
DRFI>parts is bad (produces nasty edge-ghosts) and it deinterlaces wherever
DRFI>there's motion, rather than just the areas that have combing.

If you are interested, there is some info about kerndeint (from its
author):
http://neuron2.net/journal/journal.html

And yes, it looks like it is the same filter as smartdeint, or something
close to it; at least, they are written by the same person. They seem to
use the similar technique to detect motion, but possibly deinterlacing
algorithm is different. In smartdeint, you can choose either lb, li or
ci filter (speaking in mplayer terms ;) for actual deinterlacing. I've
yet to find [dis]advantages of kerndeint comparing to smartdeint...

-- 

Vladimir