[mythtv-users] Upgrade to HD?
Michael T. Dean
mtdean at thirdcontact.com
Mon Apr 16 15:23:52 UTC 2007
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> ) 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.
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