Single Board Computer for HD XVideo?

[Luc Verhaegen]

On Wed, Jan 03, 2007 at 01:49:39AM +0900, Carsten Haitzler wrote:
> On Sun, 24 Dec 2006 11:06:27 +0000 Tomas Carnecky <tom at dbservice.com> babbled:
> 
> > Carsten Haitzler (The Rasterman) wrote:
> > > caved in and bought a microatx board - stuck an nv6600gt in it and now hdtv
> > > is slick, smooth and dreamy (using fragment shaders tho for yuv->rgb and u
> > > can do much more fun things with the video then)
> > > 
> > 
> > Why not use the XVideo extension? It can do the conversion and scaling 
> > on the card if the driver supports that.
> 
> because i can't overlay and blend multiple videos at high resolution.
> "overlays" of osd's and underlays etc. won't be limited to yuv 422 etc. i
> can get full argb32 overlays and ui elements mixed with video, blending etc.
> 
> this way video is just a normal piece of gfx with no bizarr-o colorkeyed
> overlays and limitations. they slide into a complex display pipeline seamlessly
> without arbitrary limits :)
> 
Most unichromes can have two overlays, and can compose the two overlays 
with the FB at 4bit alpha. I think that many hw overlay implementations 
of this millenium allow quite complex setups in respect to compositing 
and format conversion.

Unichromes (in general - so YMMV) support YUV to RGB texture conversion. 
So this is far from exclusive to discrete hardware. I do think that, if 
the previous is available, you should stay away from a shader based 
YUV-RGB conversion on IGP.

So, hw overlays or not, or 3D engine or not, that's not the real issue. 

It's memory bandwidth and latency that are the major issues on IGPs.
High resolution video, however it is handled, will be most limited by 
those. And this is where dedicated memory and a highly optimised RAM 
controller wins, not anywhere else.

Luc Verhaegen.