[mythtv-users] FYI - New HW video accellAPI from NVIDIA

[Jason]

On Fri, 2008-11-14 at 10:28 -0800, Andy Ritger wrote:
> I'm pleased to announce a new video API for Unix and Unix-like platforms,
> and a technology preview implementation of this API from NVIDIA.
>
> The API is called VDPAU (Video Decode and Presentation API for Unix).


I took some time today to test the new drivers with the h.264 samples from 
the Hauppauge HD-PVR on my desktop system.  The performance was impressive, 
to say the least.

I tested the three samples linked on the HD-PVR wiki entry 
(http://www.mythtv.org/wiki/index.php/HD-PVR) as well as a recording I had 
made earlier this week (a 720p program at 9Mbps).

My test methodology was far from scientific, but the results are 
encouraging.  My testing was simply done by comparing the the CPU loads 
displayed by top and the command line output of mplayer.  My desktop system 
is a Core 2 Quad (Q6600) @ 2.4GHz with 4GB of RAM and a 8800GTS card.  (I 
don't have a mythfrontend with a 8 series or later nVidia card.)

Running any of the samples I had with the standard mplayer without any 
command line args (i.e. mplayer <file>)did a pretty good job of pegging the 
CPU.  mplayer also complained that the system was too slow and audio got 
very far out of sync.  If anyone can recommend some better command line 
args, I can re-run that part of the test, as I think this comparison isn't 
quite fair.

After building the patched ffmpeg and mplayer, I re-played the samples and 
noted that there was no discernable CPU usage once playback got rolling.  In 
top, mplayer consistently showed 0% CPU usage, with a few bumps up to a few 
percentage points here and there.  Mplayer outputs CPU usage for the video 
codec, video out, and audio codec processing.  For all the samples, mplayer 
eventually settled after a minute or so into 0% video codec CPU usage, 8 - 
9% video out CPU usage, and 1.5% audio codec CPU usage.

I was able to run other programs (command line, firefox, etc.) at the same 
time and didn't notice any stuttering.

I've got a 7 series nVidia system here that I'll test with, too.  I don't 
expect it to work, but maybe there's some hidden mojo.

Please let me know if you have any questions or test suggestions.

Jason