[MPlayer-dev-eng] More on inverse telecine!

[Billy Biggs]

D Richard Felker III (dalias at aerifal.cx):

> On Mon, Apr 14, 2003 at 06:39:26AM -0500, Billy Biggs wrote:
> > > >   No I just meant filter the input scanline with a low-pass filter
> > > > before looking at absolte difference.  Like [1 4 6 4 1] before you do
> > > > the abs.
> > > 
> > > Ah, hmm... This is fairly difficult to do without serious additional
> > > computation, which would slow the process down even more. It could
> > > have some benefits, but from a mathematical standpoint I don't think
> > > you really get more info from the difference of the blurred lines than
> > > the original difference before blurring. (I'd have to sit down and
> > > work it out to be sure though...)
> > 
> > It's not that hard.  Even a [1 1 1 1] filter can help.  I've used
> > something like this successfully on YUY2 content (luma every second
> > byte):
> 
> Yes, but that ignores the fact that I'd need to do a whole block of
> current and prev. frame at a time for processing, and the ugly
> boundary conditions (what do you do on leftmost and rightmost pixels?)
> etc.

  Huh?  This is a horizontal filter, you need only a scanline from the
current field and a scanline from the previous field.  The leftmost and
rightmost pixels you can drop anyway, as the edge conditions often
contain noise anyway.

> > conflict.  If you're going straight from a DVD, you just have to
> > hope the DVD wasn't mastered from a composite format like LD or even
> > VHS (hey, I've seen it!).  If you're capturing analog, make sure you
> > capture over component, but just using S-Video can ensure your luma
> > won't be too messed up (again, depending on the source).
> 
> If the material is telecined, it's probably originally movie content,
> in which case I'm not interested in analog copies. :)

  Sure but often you get an anime of a movie that comes from tape
source.  My copy of 'Macross Plus' is one such example, the entire DVD
is expanded pulldown, and it contains artifacts.  It's clear that this
DVD was made from an analog source tape.

  -Billy