AMD is on the heels of releasing the next set of GPU programming documentation to aide in the development of the open-source R500/600 drivers (xf86-video-ati and xf86-video-radeonhd). It's already been discussed what this NDA-free documentation release will have, but one of the questions that have repeatedly come up is if/when AMD will release information on accelerated video playback. AMD's John Bridgman has now stated what they plan to release in the video realm as well as a new requirement for their future graphics processors: being open-source friendly while avoiding DRM.
On the RadeonHD IRC channel (logged at RadeonHD.org), John Bridgman (on the Phoronix Forums known as bridgman) has stated that they'll be releasing IDCT (Inverse Discrete Cosine Transform) and MC (Motion Compensation) information for everything up to and including the Radeon X1000 "R500" series. The IDCT/MC information can be used for hardware-assisted video decoding. Open-source video playback on the Radeon HD 2000 "R600" series, however, is a different story.
For the R600 series (and presumably the R700 series as well), it features a Unified Video Decoder (UVD) unit for H.264 and VC-1 video decoding. While this is great for the hardware, the problem resides with the decoding functionality being combined with the Digital Rights Management (DRM) operations. If AMD releases the UVD information to the public on the R600 series, they will be able to use the video decoding but then DRM will be put at risk. With this information, users could then bypass DRM on Windows, which could then place AMD into legal hot water.
While there is no easy way around this for the R600 series, John Bridgman has stated "[a modular version of the UVD is] already on the requirements list for future chips. Won't make the next generation (too far along already) but the ones in early development should be more open-source-friendly." However, we don't know exactly how open their next generation of GPUs will be. As Bridgman had then stated, there is some cost (manufacturing and performance) to a modular design but branching DRM from the video decoding functionality should work out.
At this point, it's "less than [a] 50/50 chance of opening UVD", but the final outcome won't be known for a few months. For the R500 series, the hardware-accelerated video playback will not come until the 3D foundation has been laid, so that as well is a few months out.
The good news coming out of this is confirmation that future AMD Radeon GPUs should be more open-source friendly (at least when it comes to accelerated video playback), but the fruits of that will not be present until at least the R800 or R900 generations (unless of course DRM were to get thrown out altogether). Once the 3D acceleration is in place, there should be accelerated video playback for the R500 series through the open-source RadeonHD driver, but that too is a ways out. With time, AMD will be going back and releasing greater documentation on its earlier product families so those owners may be in luck as well.