HD On The PC: Increasingly Feasible

I wasn't at Computex two weeks back, but apparently ATI Technologies was demo'ing hardware-accelerated H.264 video playback on its "next generation Radeon technology" (which I assume is the long-delayed R520). This is excellent albeit expected (H.264 is an industry standard, after all) news. The shader processors inside modern GPUs, which are conceptually similar to DSPs, enable the vendors to more quickly support new and evolving video codecs than in the past hardwired circuit approach used with MPEG-2.

In a recent conversation, John Setel O'Donnell, CTO at Equator Technologies (which is in the process of being acquired by Pixelworks), estimated that at an equivalent quality level to Windows Media Video 9, H.264 (aka MPEG-4 AVC, aka MPEG-4 part 10) was roughly 2.3x more performance demanding than the Microsoft-developed alternative codec. If his estimate is accurate, even latest-generation PC CPUs would find it difficult-to-impossible to decode a high definition H.264 bitstream without dropping frames, if they employed a fully software-based algorithm that didn't harness hardware help from the graphics subsystem.

H.264 content is still scarce; high def WMV9 is more mature and material is more prevalent. And hardware acceleration support, which to date has been minimal and unofficial, just got a big boost courtesy of a Microsoft enhancement to DirectX Video Acceleration under Windows Media Player 10. You'll need to make sure your graphics card's drivers take advantage of the tweak. Nvidia touts host processor load reductions of up to 40 percent. Which is nice. Although not a Nvidia-only perk.