[mythtv-users] New deinterlacer for perfect image quality when using an interlaced display, mode that matches the source

[Paul Gardiner]

Tom Dexter wrote:
> OK...I've tested that new change with the 'parity' parameter
> defaulting to 1 for non-interlaces frames and everything looks great.
> That definitely seems to be the way to go.

Great news. I think we can go with that version. One of us should
upload a patch. Shall I, or do you want to?

> One small cosmetic thing I've noticed, and I believe it's been the
> case with all versions:  When I have OSD fade enabled and there's any
> situation where more than one thing displays via the OSD at a time,
> the fade caused some video stuttering.  One place I tend to see it is
> if I save my place in the recording...that displays the message saying
> the position has been saved in addition to displaying the progress
> bar.  When those fade it tends to stutter a bit.  I also get a CPU
> spike when that happens.  This never occurs with any single OSD
> overlay, and also doesn't happen if I disable fading.
> 
> Very minor for sure.  I see that it doesn't happen with bob x2.

That's probably not surprising. I think with bob the OSD is rendered
to Bob's halfheight buffer. Everything's a lot cheaper with bob.
You might find the same stutter with yadif. There is some room for
speeding up field order using faster memcpy. Perhaps should look at
that sometime.

> By the way, I took the time to do some comparisons between this
> deinterlacer and bob x2 that I was using before.  Wow...the difference
> is _not_ subtle at all.  This thing has definitely cured the one major
> flaw I've lived with since I built the system two years ago.  Great
> stuff.

I'm still sometimes seeing slight strangeness in motion. And sometimes
I think I prefer yadif. Certainly rolling text credits show that field
order is doing exactly what it should, but I wonder whether there are
periods in normal playback where the mpeg decode is complex, which
leads to the sync changing rappidly. yadif may cope with that better.
The other possibility I can think of is that the slight blurring due
to yadif is sometimes beneficial.

Cheers,
	Paul.