WebM: Not Ready for Prime Time?
Jason Garrett-Glaser, one of the open-source community developers who worked to reverse-engineer H.264 compression into a codec dubbed x264, commented on the lack of documentation-and even the lack of a true specification-in a blog post shortly after Google's announcement.
"The spec consists largely of C code copy-pasted from the VP8 source code," said Garrett-Glaser, "up to and including TODOs and 'optimizations' . . . In many places it is simply outright opaque. Copy-pasted C code is not a spec. I may have complained about the H.264 spec being overly verbose, but at least it's precise.
"The VP8 spec, by comparison, is imprecise, unclear, and overly short," he continues, "leaving many portions of the format very vaguely explained. Some parts even explicitly refuse to fully explain a particular feature, pointing to highly-optimized, nigh-impossible-to-understand reference code for an explanation. There's no way in hell anyone could write a decoder solely with this spec alone."
The latter-a compliant decoder-is the key to the technology working seamlessly across browsers and other players. As with H.264, the way of encoding is left up to the codec implementation, but all files must be able to decode and play back in a consistent manner. Should Google not choose to address a more proper decoding solution, the risk is incompatibility between playback devices.
The Business Model
Google appears to have two primary interests in its open-sourcing strategy: covering its own back and offering something of potential (although untested) value to the open-source community.
As many have pointed out, the On2 acquisition is a financially insignificant insurance policy for Google, so that its long-term video and video search strategy won't be beholden to H.264 patent holders, including Apple and others that are part of the MPEG-LA patent pool.
Beyond just a way to avoiding a significant headache down the line, the open-sourcing of VP8 is also a way for Google to counteract perceptions that it is dominating the online video market through its highly searched YouTube online video site. The best way to fight a negative perception is with a positive one, and the "giving away" of the VP8 codec to the video market has all the hallmarks of a positive public relations move, even if the reality doesn't jibe with the perception. We'll cover that more in the licensing article.
A final way that Google is covering its bases goes back to the HTML5 video and audio tag discussion. For those who may have missed the discussion core, an article on codec choice within HTML5 browsers will provide a good overview.
In a nutshell, the browser wars divided core playback capability between Ogg Theora and H.264, with some browser manufacturers supporting one or another codec, while others supported both or neither. The specifications editor for the HTML5 working group, Ian Hickson, left an opening last July-prior to Google's announced intent to buy On2-that a better-quality open-source video codec could be hardwired into the HTML5 video tag. Given Google's announced verbal support by a large number of browser manufacturers, it is quite possible VP8 (or even WebM) becomes the hard-coded standard for video and audio in the majority of web browsers.
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Google seems more concerned with modifying its WebM FAQ than it is with helping the online video world understand the practical and financial benefits of an open-source competitor to H.264.
10 Jun 2010