AMD Toying With XvMC In Gallium3D R300 Driver

[highlandsun]

So does anyone have build instructions for r300g with XvMC support? And what needs to be installed so it can be used by e.g. mplayer? Unlike the previous poster who said this is useless, I still have a couple computers at home with R300 GPUs and I'd like to be able to finally make use of them.

[bridgman]

IIRC the Evergreen family (HD54xx and up) includes a few Sum of Absolute Differences shader instruction variants so one obvious task would be using those instructions to speed up motion estimation... details in the Evergreen shader instruction doc on our Stream site.

[bridgman]

Maybe ask Dark_Shikari ? I haven't heard a thing about it.

[popper]

before and after short samples posted somewere would be a nice thing to have to evaluate its use if its far enough along in the beta cycle too?

park and Birds might be nice and some studio quality 2K/4K live action samples if possible.

[popper]

bridgeman , agd5f or whoever, whats this i hear that AMD is sponsoring development of a GPU codec ? what and were can i read about this ?

"they explicitly designed a codec to fit the gpu parallelism model"

what is this GPU codec based on ? AVC or something else?
and have you written the decoders for it and opened up its codebase yet?

"IRC
<Dark_Shikari> hmm, interesting. apparently AMD is sponsoring development of a GPU codec designed to sacrifice some compression to get vastly better parallelism on GPUs
<Dark_Shikari> since GPU H.264 encoders are garbage and they know it
<Dark_Shikari> apparently they can do 4K @ 120fps with a top-end ATI card
<giwe> what is the 4K parameter?
<J_Darnley> the resolution
<Dark_Shikari> 4000x2000 or similar
<giwe> huge
<J_Darnley> Oh, so not 4000p like 1080 and 2160
<Dark_Shikari> so quad 1080p
<Rodeo> still huge
<Dark_Shikari> thus, 1080p at 480fps
<Dark_Shikari> well, assuming it scales perfectly which it probably doesn't
<J_Darnley> very nice though
<Dark_Shikari> but, equally, 4 1080p streams at 120fps each
<Dark_Shikari> or 16 1080p streams at 30fps each
<Dark_Shikari> where a top-end core i7 can probably do about 3-5 with x264
<Dark_Shikari> which seems reasonable, a GPU should be able to have at least 4x the power if properly leveraged
<JEEB> Yah, they loose in compression, but at least they'll be able to keep speed
<pengvado> 2000p x 120fps is with what candidate codec?
<Dark_Shikari> pengvado: some custom made one
<Dark_Shikari> the point being they explicitly designed a codec to fit the gpu parallelism model
"

[darkbasic]

XvMC code is already in place in gallium so much of the work is already done in that case.

Do you know if someone is already working on the va-api through gallium backend?

[popper]

its always sad when you realise that SOC ( the payed Google Summer Of Code project) gets you more real features (Proof Of Concept or not) than other 3rd party devs actually deliver on their word for their updated code (free* Glibc SIMD refactored replacements for many CPUs to increase overall speeds for instance that never materialises) over the years and thats a real shame.

[Smorg]

Always good to hear of AMD working on free software. It's why I buy their stuff.

[drag]

It's a API that exists and is supported by a lot of applications. Sure; high-res mpeg2 is not a big deal anymore cpu-wise, but it's still nice to have.

If somebody can add support with a patch like this it just helps confirm the design of Gallium and the quality of AMD's documentation and support as it would take years to get support like that previously.

[agd5f]

XvMC? Oh come on, this is useless. Hardly anyone needs MPEG2 decode acceleration nowadays. Besides, it would make more sense to support a modern API like VDPAU/VA-API instead of XvMC, even if it's just for MPEG2.

The information is all there. Patches are welcome. It just so happens that the XvMC code is already in place in gallium so much of the work is already done in that case.