[mythtv-users] Quality difference between software only and Nvidia XvMC

[Michael T. Dean]

On 03/06/2010 06:46 PM, Erik Burrows wrote:
> I have a mythtv front-end with a Nvidia Quadro FX 580. I've been happily
> using it to display 1080i content captured via firewire from cable.
> Worked great, no issues.
>
> Today I looked into taking full advantage of the Nvidia chipset's XvMC
> capability. Following the instructions at
> http://www.mythtv.org/wiki/XvMC, I got it working. Happily, my cpu
> utilization was cut by more than half, which is great.
>
> What was not so great, was that the quality of the video playback
> suffered. I saw more jitter in the images, and more compression
> artifacts.
>
> Is this normal, and to be expected, or is there some sort of quality
> control knob I need to turn?
>    

XvMC is garbage.  If you want to use 
other-than-software-decoding-on-the-CPU, use VDPAU, which will do 
decoding on the GPU.  You may have to buy a $20-$40 nvidia video card to 
use VDPAU, if yours doesn't support VDPAU.

Mike