[mythtv-users] Upgrade to HD?

[Michael T. Dean]

On 04/16/2007 10:43 AM, Tom Flair wrote:
> Does XvMC accelerate/improve the playback of MPEG4 content?  I thought 
> it was only usable for MPEG 1/2.  A brief overview of the wiki 
> (http://www.mythtv.org/wiki/index.php/XvMC 
> <http://www.mythtv.org/wiki/index.php/XvMC> ) supports this theory.  
> Or am I missing an HD, mpeg2 or TS of Elephant's Dream on their 
> download page?

XvMC can be used to assist decoding of any video coded with a CODEC that 
uses Motion Compensation (MC) and/or Discrete Cosine Transform (DCT).  
(XvMC provides optional support for iDCT, which reverses the DCT used to 
code the video, so, yes, I did mean DCT there--not to mention that iDCT 
is really just a type-III DCT.)

MPEG-4 does use both MC and DCT.  However, for XvMC to be usable for 
CPU-decode-assist, both the application and the video card drivers must 
have support for use of XvMC with the given CODEC.

The NVIDIA drivers do not support the use of XvMC with MPEG-4 (only with 
MPEG-2).  I seriously doubt they ever will, either (but that's another 
story) as there's a better approach available.

IIRC, either Via or Intel (or both) is working on or has support for 
XvMC with MPEG-4.

Mike