Re: [Linux-fbdev-users] probably an FAQ - g450 vs g400 tv out?

[Ville <sy...@sc...>]

On Tue, Sep 11, 2007 at 09:06:28AM +0930, davidm wrote:
> Umm. X on the tv-out doesn't seem to present any useful Xvideo
> extension, and I was assuming that the reason for that was that it
> required stuff on crtc1. Is that a false assumption?

I know the Xorg mga driver supports using the texture engine for Xv but
I don't know if it still has some limits on what it supports on CRTC2.
When I last used that driver years ago it didn't support any acceleration
on CRTC2. Also I don't know if the driver supports vsync or triple
buffering for Xv.

> Would a g400
> (instead of a 450) change this? Without the xvideo layer my p3@1GHz
> seems to not be fast enough to do anything useful under X.

With a G400 you might be able to swap the heads like you intended and
overcome the driver limitations by using the BES. I won't guarantee that
it will be succesful though since the X driver might revert whatever
changes you make via matroxfb, and since it's using the binary HAL (or has
that changed?) changing it's behavior might not be easy.

> Actually it occurs to me now that even if X did present a nice Xv
> extension on the tv-out, would mythtv (or any other player for that
> matter) have any mechanism for playing interlaced video with the correct
> synchronization? (Using mplayer's dfbmga output layer I need to set
> fieldparity=top and vsync=1, and I'm not sure there would be any way to
> do the equivalent? It would be rather sad to have to deinterlace the
> video in software only to display it on an interlaced TV!).

I think the driver could have an Xv attribute for field parity.

-- 
Ville Syrjälä
sy...@sc...
http://www.sci.fi/~syrjala/