KVR Audio

fac · Post by **fac** » Tue Apr 15, 2008 9:16 pm

Does anyone know any resources for low-level GPU programming, for example, to perform convolutions or matrix operations outside the CPU?

jupiter8 · Post by **jupiter8** » Tue Apr 15, 2008 10:42 pm

There's CUDA for the newer Nvidia cards.
http://www.nvidia.com/object/cuda_home.html

I believe ATI has something similar though that could be my mind playing tricks on me.

UltraJv · Post by **UltraJv** » Tue Apr 15, 2008 10:51 pm

Seems that CUDA is really the only current standard. I use that term loosly as theres really not much audio stuff available for it. A few people attempted to do the same on less expensive cards but it never really took off. CUDA requires Nvidia Gforce 8400GS cards and over. IMHO its better to go native or develop for the other DSP cards like Creamware etc as they have an existing user base.

jupiter8 · Post by **jupiter8** » Tue Apr 15, 2008 11:11 pm

UltraJv wrote: CUDA is expensive (Nvidia 8800 cards and over).

Nah. That was way back. Now even the lowly 8400 GS supports CUDA.
http://www.nvidia.com/object/cuda_learn_products.html

UltraJv · Post by **UltraJv** » Tue Apr 15, 2008 11:13 pm

just corrected it to 8400GS lol - None of my computers supports even that yet, I hate noisy fans.

VitaminD · Post by **VitaminD** » Tue Apr 15, 2008 11:51 pm

The 8800GT is only ~$150 USD these days.. not that expensive.. In july theres supposedly going to be a 9800GT.. I think I'll jump on board then..

fac · Post by **fac** » Tue Apr 15, 2008 11:54 pm

Thanks for the links.

It's too bad that even these days, there are no standard GPU low level API's, when even a cheapo card can do a lot of stuff. Seems like a waste of power, unless you're a gamer or a designer.

VitaminD · Post by **VitaminD** » Tue Apr 15, 2008 11:57 pm

yeah.. the Folding@home folks have a client for ATI cards.. which is kind of cool.. shame (for me) that I only use Nvidia these days.. hopefully they'll port it to nividia cards one day...

FEV · Post by **FEV** » Wed Apr 16, 2008 6:20 am

fac wrote:Does anyone know any resources for low-level GPU programming, for example, to perform convolutions or matrix operations outside the CPU?

http://libsh.org/

cheers,
Bart

dunk · Post by **dunk** » Thu Apr 17, 2008 9:26 pm

If you look at the Nvidia SDK, the example "gpgpu_fluid" is a fluid dynamics sim running that will run on most DX9 GPUs I think - I've had it running on my old GeForce FX5700 here and at work I've got it running on the XBox360 GPU. I think the streamops and other base classes and ideas used in the gpgpu fluid demo are what went on to be developed into CUDA (I could be wrong though as I haven't read up on CUDA so don't really know what it involves).

GPGPU info:
http://en.wikipedia.org/wiki/GPGPU
http://www.gpgpu.org/

AFAIK - if your GPU supports DX9 vertex/pixel shaders and floating point textures, you should be able to encode audio into a texture and handcode shaders to do processing for you. I've not looked into it before but presumably CUDA does a lot to help the rapid encoding and decoding of information to / from texture formats and streaming the textures as efficiently as possible to the GPU. Trying to go to the metal and do it yourself in HLSL or CG without CUDA could be a major pain in the arse (as I found in the various stages of trying to debug my implementation of the fluid sim) due to the pain of trying to debug GPU processes ... but it'd be nice to leverage the vector chomping power of GPUs for audio

fac · Post by **fac** » Thu Apr 17, 2008 10:16 pm

Thanks, dunk. That was very useful.