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Transcoding in 1/5 the Time with Help from the GPU
mikemuch writes "ExtremeTech's Jason Cross got a lead about a technology ATI is developing called Avivo Transcode that will use ATI graphics cards to cut down the time it takes to transcode video by a factor of five. It's part of the general-purpose computation on GPU movement. The Aviva Transcode software can only work with ATI's latest 1000-series GPUs, and the company is working on profiles that will allow, for example, transcoding DVDs for Sony's PSP."
Maybe others have had this idea. Maybe it's too expensive or just not practical. Imagine using PCI cards with a handful of FPGAs on board to provide reconfigurable heavy number crunching abilities to specific applications. Processes designed to use them will use one or more FPGAs if they are available, else they'll fall back to using the main CPU in "software mode."
This should be written in Shader Language (or whatever it's called these days) which is portable between cards. There's no reason NOT to release this on any platform. Since it only runs on the latest ATI cards it probably uses some feature that nVidia will have in it's next batch of cards as well. If ATI doesn't release it for Linux and the Mac hopefully it won't be that difficult to duplicate their efforts. After all, shader programs are uploaded to the video driver as plain text.... ;)
I'd like to see it but I wonder what the quality is going to be like as compared to the best current encoders. I mean you can already see a big difference between cinema craft and j. random mpeg2 encoder...
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the X1800XT ties almost exactly with the 7800GTX @ stock of 430 core in most gaming benchmarks.
with nVIDIA's 512mb implementation of the G70 core touted to be at 550mhz core, it should theoretically thrash the living daylights out of the X1800XT.
http://theinquirer.net/?article=27400
the decision is between aVIVO's encode and transcode abilities for h.264, or superior performance by nVIDIAs offering?
Video cards with GPU's used to be a "cheap" way to increase the graphic processing power of your computer by adding a chip who's sole purpose was to process graphics (and geometry, with the advent of 3d-acellerators).
Now that GPU's are becomming more and more programmable, and more and more general~purpose, what, really, is the difference between a GPU and a standard CPU? What is the benefit to having a 3d~acellerator over having a dual~CPU system with one CPU dedicated to graphic processing?
FPGAs aren't always slower than what you can do in silicon. AES [sorry I have a crypto background] takes 1 cycle per round in most designs. You can probably clock it around 30-40Mhz if your interface isn't too stupid. AES on a PPC probably takes the same time as a MIPs which is about 1000-1200 cycles.
... so that 1000 cycles is 100 FPGA cycles. But an AES block takes 11 FPGA cycles [plus load/unload time] so say about 16 cycles. Discounting bus activity [which would affect your software AES anyways] you're still ahead by ~80 FPGA cycles [800 PPC cycles].
Your clock advantage is about 10x [say] that is typical 400Mhz PPC vs. 40Mhz FPGA
Though the more common use for an FPGA aside from co-processing is just to make a flexible interface to hardware. E.g. want something to drive your USB, LCD and other periphs without paying to go to ASIC? Drop an FPGA in the thing. I assure you controlling a USB or LCD device is much more efficient in an FPGA than in software on a PPC.
Tom
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wow, for once there's a slashdot article i have insight on! (whether it's modded that way remains to be seen.... ;) )
i would actually be shocked if there weren't linux support. the ability to do what they want only need to be in the drivers. i've been doing a gpgpu feasability study as an internship and did an mpi video compressor (based on ffmpeg) in school. using a gpu for compression/transcoding is a project i was thinking of starting once i finally had some free time since it seems built for it. something like 24 instances running at once at a ridiculous amount of flops (puts a lot of cpus to shame, actually). if you have a simd project with 4D or under vectors, this is the way to go.
like i said, it really depends on the drivers. as long as they support some of the latest opengl extensions, you're good to go. languages like Cg and BrookGPU, as well as other shader languages, are cross-platform. they can also be used with directx, but fuck that. i prefer Cg, but ymmv. actually, the project might not be that hard, just needs enought people porting the algorithms to something like Cg.
that said, don't expect this to be great unless your video card is pci-express. the agp bus is heavily asymmetric towards data going out to the gpu. as more people start getting the fatter, more symmetric pipes of pci-e, look for more gpgpu projects to take off.
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Though I am sure you wrote that as a pure joke, this has already been done long ago. During the fierce competion on the demo scene between the ATARI ST and the Amiga, crews were exploiting every speck of power they could from their machine. The ATARI ST being a general purpose machine compared to the Amiga (which had very advanced sound and graphical custom processors), the programmers who wanted to pull off the same graphical effects went as far as using the processor managing the keyboard (a 68xx 8bit motorola chip) for added computational power.
A GPU is, effectively, a very wide vector unit (1024-bits is not uncommon). What happens when CPUs all include 2048-bit general purpose vector units? What happens when they include a couple on each core in a 128-core package? Sure, a dedicated GPU will still be faster - but it won't be enough faster that people will care. For comparison, take a look at Chromium. Chromium is a software OpenGL implementation that runs on clusters. Even with relatively small clusters, it can compete fairly well with modern GPUs - now imagine what will happen when every machine has a few dozen cores in their CPU.
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