Multimedia: Mostly The Same, Plus High-Def Audio

With all of the hardware resource-doubling, DirectX 11-adding, and Eyefinity business going on inside of Cypress, it’s hardly a surprise that nothing has changed, as far as hardware is concerned, in what the GPU can do with regard to video playback. The Radeon HD 5870 continues to boast ATI’s Universal Video Decoder 2.

As you already know, this includes a number of post-processing capabilities, like an advanced temporal de-interlacing algorithm, inverse telecine (pulldown detection), upscaling, dynamic contrast adjustment (though we’ve been critical of image-altering technologies like this in the past), and noise reduction. UVD2 also enables full decode acceleration of MPEG-2-, VC-1-, and H.264-encoded video. It’s able to offload two 1080p video streams simultaneously, enabling the picture-in-picture acceleration seen on previous-generation cards by compositing one image over the other in the GPU’s shaders.

But even though RV790 features 800 shaders, composition efficiency concerns made it necessary to disable Windows’ Aero user interface any time a Blu-ray disc was played back (this wasn’t an issue with standard-definition content). Now, ATI is saying that Cypress supports playback of Blu-ray content (again, even dual-streams) without having to turn off Aero, thanks to the dramatic increase in shader compute performance. Specifically, the number of HD composition passes has been reduced in the shaders, alleviating the load.

By default, this is disabled in PowerDVD 9 as a performance consideration. However, if you enter the settings and configuration menu (this is in the preview build), click the Blu-ray tab, hit the Advanced button, and uncheck the option to exit the Aero interface upon playback, this works perfectly.

Could A Graphics Card Kill HTPC-Oriented Sound Cards?

Much more exciting for home theater enthusiasts, however, is ATI’s claim that with this generation’s hardware it has a protected audio path in place. As you have no doubt read from our previous attempts at setting up the perfect Windows 7-based HTPC, we’ve only tested one product able to bitstream Dolby TrueHD and DTS-HD Master Audio from a Blu-ray disc to your stereo receiver over HDMI: Asus’ Xonar HDAV 1.3. We have Auzentech’s X-Fi HomeTheater HD in the lab as well, and the general consensus seems to be that is an even better solution. But the point is that up until now, there were only a couple of sound cards enabling this capability.

The next best thing would be decoding those two high-def formats in software and outputting uncompressed multi-channel LPCM audio. The issue here is that today’s software players are not allowed to send anything better than CD-quality audio to the receiver (16-bit, up to 48 kHz) due to the AACS, so if you’re watching/listening to something like The Police: Certifiable (24-bit, 96 kHz), you’re not getting bit-for-bit fidelity.

Currently, the caveat is that a claimed protected audio path alone isn’t enough. A company like CyberLink has to work with the IHV to make sure it won’t make the lossless stream vulnerable over a user-accessible bus. Fortunately, ATI already has a driver that enables this (it’s certainly beta, given the install procedure) over HDMI 1.3a connections.

But the software isn’t quite ready. We received a beta build of PowerDVD 9 put together at the last minute to preview this functionality in action, but pass-through of TrueHD and DTS-HD simply wasn’t working with our Onkyo TX-SR507 receiver (though I've spoken with colleagues who've had no trouble getting bitstreaming to work). The good news is that this isn’t a capability way off on the horizon, though. ATI and CyberLink are working on it right now, and we’d expect support to be shored up in days or weeks rather than months. And that’s fine with us—most HTPC enthusiasts won’t be putting a large dual-slot graphics card in their theater room. This functionality will really come into its own when the Juniper-, Redwood-, and Cedar-based variants emerge later this year and in 2010.