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

[Paul Gardiner]

Tom Dexter wrote:
> An update on my ongoing testing.  Since it takes me over an hour to
> compile, and the fact that I can't do it during evening TV watching
> time :D, I'm a little limited as to when i can do this sort of stuff.
> 
> First of all, I noticed the same motion issues with my recording of
> Law and Order: SVU from Tuesday...so I have more content to test with.
> 
> This morning I compiled with your original patch (the one without the
> OSD flicker fix).  Believe it or not, both shows look fine with
> that...no problems at all.  I even watched a good portion of Medium
> over again to make sure.

That's good news. If nothing else, at least this means you have a
solution. It also has to be very useful information for getting
to understand the problem.

> Tomorrow morning I'm going to try again with the version of the
> original patch that has to OSD flicker fix just to see if for some
> reason that's related.

Yeah, that would be a good test. I'd expect the problem to return
with that patch because, as far as I can tell, it does the same job
as Mark's verion. If the problem does return, one more change worth
trying is to change - in function "filter_func" - the inner condition
from

((y ^ tff) & 1) == 0

to

y & tff


The no-flicker patch actually has two alterations, one to remove the
flicker and the other to deal with bottom-field-first content. The
change I suggest above will retain the flicker fix, but revert the
bottom-field-first fix.

> I don't know if this means anything, but I
> noticed something interesting.  For me the OSD flickering (without the
> fix for it) seems to primarily be an issue with content that has those
> progressive frames mixed in...the same sort of content that tends to
> cause the motion issues.  Tonight my wife is watching Survivor, which
> is in 1080i on CBS...but those sorts of shows (unlike dramas on NBC
> and CBS) never have the progressive frames from what I've seen.
> Interestingly, while watching that there's almost no noticeable OSD
> flicker, even in the playback menu.  That's still using the original
> patch.

That's interesting. That again may tell us a lot.

I find it hard to see the flicker problem sometimes. I wondered
whether it shows only when some movement in the picture causes your eyes
to scan the screen.

> In any case this all would seem to rule out decoding or dropped frame
> issues, as that's all been the same in both tests so far.

I guess it's still possible but unlikely: there's a small possibility
that the difference in efficiency of the two versions might be just
enough to cause frame dropping. Come to think of it, both Mark's and
my flicker fixed versions do 50% more memcpys than the non fixed one.

> I'll post back tomorrow after more testing.

Great. Hopefully we can get this sorted eventually.

Cheers,
	Paul.