In a post on his personal blog, Matthew Gregan from Mozilla has provided some benchmark numbers for Theora video being decoded entirely in hardware on a Nokia N900 mobile device. Gregans work, which is aimed at integrating hardware accelerated Theora decoding into the Firefox web browser, builds on the work of others like David Schreef from Entropy Wave, who was contracted by Mozilla last year to port the Theora codec to the Texas Instruments C64x+ Digital Signal Processor found on many devices like the Palm Pre, the Motorola Droid, and of course the N900 mentioned above.
Gregan reports that the current codebase he is working from can display full screen Theora video without loading down the main CPU or killing the battery:
Playback (video decode + paint, audio decode + not played). DSP decoding video:
Method FPS (800×480) Idle CPU SDL/overlay 33 20.0% OpenGL/bc-cat 26 81.4%
Keeping the CPU idle while displaying full screen, full speed video playback with audio is the goal, and Gregan has demonstrated that while results are not yet perfect, Theora is very close to being able to display 30fps video while keeping the CPU mostly idle.
For some background, Theora is one of a handful of video codecs being pushed as the “standard” video codec for mobile and HTML5 video. The other major contender, h.264, is considered by some to be technically superior and has broad industry support for hardware decoding, but is covered by patents and subject to licensing fees. Some vendors have thrown their weight behind h.264 because of hardware decoding support found in the processors used by devices like the iPhone, despite the licensing fees.
However, other vendors such as Mozilla, have repeatedly said that h.264 just isn’t an option for products like Firefox due to the licensing costs and the restrictions on distribution of code that would result if they were to include an h.264 decoder in the software itself. Until now, alternatives like Theora were a non-starter on mobile devices due to lack of hardware decoding support in common processors, but this recent demonstration by Gregan and others proves that, while there are certainly other legal and technical concerns, efficiency on mobile devices may not be the dividing line that keeps Theora from being considered a viable solution.