[Openchrome-users] xvmc support for mplayer

[Mario Emmenlauer]

Hi,

John Robinson schrieb:
>> Regenerating keyframe table for MPEG-4 video.
> 
> Your AVI contains an XviD MPEG-4.
> 
> [...]
>> Forced video codec: ffmpeg12mc
> 
> That codec only handles MPEG-1 and -2. There isn't currently any support 
> for the MPEG-4 acceleration capabilities which exist in a very few 
> Unichrome Pro chips. If I recall correctly that's because it's slower 
> than using the CPU - even a crummy C3 - so not worthy of the name 
> "acceleration".

I've read the same statement about the mpeg4-acceleration quite a few
times already, and always wondered if it's entirely true. I own a
CN400-based board (yep, one of the few (in theory) mpeg4-accelerating
chipsets).

After getting xvmc to work with Xorg 7.1 and the xorg-drivers, mpeg2
runs awesome with almost zero cpu. But mpeg4 also got faster with xine,
at least as far as I can tell. If I'm not entirely mistaken, the cpu-load
at least halved. I was previously unable to watch DVD-resolution XviD
with Qpel and GMC, and now it even runs smoothly. If anyone is really
curious I can do some benchmarks.

Maybe I misunderstand something here? Or is there really some
mpeg4-acceleration in the driver (and some chipsets), that is quite
worth the mentioning?

Cheers,
  Mario