Moving this discussion out of the open source 6xx/7xx thread...

Quote Originally Posted by Dieter View Post
Look at

http://www.x.org/wiki/RadeonFeature

XvMC is listed as TODO across the board. When can we expect to
see FLOSS AMD/ATI drivers supporting XvMC?
There hasn't been much interest in XvMC so far -- general feeling seems to be that even a laptop CPU can handle MPEG2 decoding well enough. There seem to be an increasing number of HD MPEG2 use cases, and we have already released enough information to implement MC on 5xx (and, as of today, 6xx/7xx I guess) but nobody has even asked how to implement it, which surprises me. We have IDCT on the list of hardware to try and open up, but given the lack of interest in MC it doesn't seem like a real priority (MC eats more CPU time than IDCT and is probably easier to implement).

If the issue is simply that not enough developers know how to implement XvMC then we could probably put together a sample implementation to get things started, but nobody seems to even ask about XvMC let alone show any interest in implementing it. I guess the issue is that the only place XvMC really buys you much these days is playing HD resolution MPEG2 streams, typically from off-the-air HDTV (ATSC, DVB), and not many people seem to do that.

EDIT -- I might have found the answer. The "classic use case" for XvMC was European digital TV, which was heavily standardized on MPEG2 at HD resolutions. Looks like many countries have already jumped ship to MPEG4 for most of their HD broadcasts, so the demand for HD MPEG2 acceleration seems to have evaporated. Given that, I think interest in XvMC is going to continue to be lukewarm until there is some agreement on an API which cleanly handles H.264 and VC-1 as well, whether it be an XvMC extension or something new like VAAPI, XVBA or VDPAU.

Quote Originally Posted by Dieter View Post
> There hasn't been much interest in XvMC so far

Perhaps you missed Phoronix's "2008 Linux Graphics Survey"?

The #1 activity was video playback, listed by 37.90%

"the second area with the most interest is seeing video improvements to X.Org"
Chart says 21.26%

Video playback/acceleration was listed by 15.09%

"When it comes to video playback improvements, the leading open-source solution
right now is through XvMC"

A related feature, TV-out was listed by 19.6%

http://www.phoronix.com/scan.php?pag..._results&num=1

> I guess the issue is that the only place XvMC really buys you much these
> days is playing HD resolution MPEG2 streams, typically from off-the-air
> HDTV (ATSC, DVB), and not many people seem to do that.

Does the date 2009-02-17 mean anything to you? Do you actually think that
not many people watch TV?

So there is need/interest. When will FLOSS drivers accelerate mpeg decoding
on AMD/ATI GPUs?