[mythtv-users] nVidia interlace problem

[Alex Butcher]

On Thu, 13 Nov 2008, Paul Gardiner wrote:

> Alex Butcher wrote:
>> On Thu, 13 Nov 2008, Paul Gardiner wrote:
>> 
>>> I've seen some posts about problems with interlacing on nVidia
>>> cards, but I've been unable to pick up exactly what the problem
>>> is.

[...]

>> Output to Xvideo (e.g. MythTV playback) appears to have every other 
>> scanline
>> doubled, so I need to use the linearblend deinterlacer in order to get
>> correct shapes (e.g. BBC Four logo is excessively aliased without
>> deinterlacing).
>
> Damn! Game over I guess. Don't understand the description quite: in what
> sense doubled?

OK, imagine the framebuffer contains:

*-*-*-*
-*-*-*-
****---
----***

Field 0 should be

*-*-*-*
****---

and field 1 should be

-*-*-*-
----***

Xv output appears to have both fields being identical (either field 0, or
field 1).

HTH,
Alex.