[mythtv-users] Nvidia CUDA / HD decoding

[Todd Ignasiak]

On 2/18/07, Michael T. Dean <mtdean at thirdcontact.com> wrote:
> On 02/18/2007 06:19 AM, Mark Kendall wrote:
> > On 2/18/07, Blammo <blammo.doh at gmail.com> wrote:
> >
> >> Short of doing something like that, are there any other optimizations
> >> that come to mind, making that type of playback easier? XvMC can't do
> >> anything for, H.264 for example, as far as I can tell...
> >>
> >> For what it's worth, I can play back some of the most intensive 1080p
> >> content I've found (several of the BBC demos) on a Athlon 64 x2
> >> @2.9ghz, at about 80% CPU. I'd imagine that's about 50% more
> >> horsepower than most people are packing in their front ends right
> >> now.. certain more than my main frontend.
> >>
> >> thoughts?
> >>
> >
> > Well, I'm sure there's plenty that can be offloaded to the GPU (and
> > Google will give you a starter for 10 with h264 offload) but I'm not
> > sure CUDA is the way I'd go. It's specific to Nvidia hardware (and top
> > end at that) and it's not exactly a standard. Before I'd invest a
> > large amout of time in working with something like this, I'd llike it
> > to be a portable standard that doesn't require a special version of
> > the driver to run.
> >
> > What's more, a lot of the power (but maybe not as flexible) can be
> > accessed through opengl already.
>
> Yep.  And, with OpenGL and OpenGL Shading Language (GLSL)--which is a
> mandatory part of OpenGL 2.0+, and, therefore, supported by ATI and
> NVIDIA drivers--and a sufficiently new video card (i.e. GeForce 6800+ or
> Radeon R520 (don't remember which cards use that chip)), you can program
> the programmable shaders to do 100% of the decoding on the GPU (rather
> than just motion compensation and inverse discrete cosine transform, as
> with XvMC).  You have to have a pretty new card to get support for
> sufficiently complex programming to allow decoding on GPU.

That sounds excellent.    Since it's part of OpenGL, does this mean
that it will be more open, and definitely be available in Linux (and
Mac OS X)?      As we all know, hardware capabilities have not always
translated into usable features..  Radeons have been doing MPEG2 accel
for over a decade, but you still can't use it in Linux.