Google's WebM draws praise, critiques
- — 21 May, 2010 03:57
The news this week of Google's open-source release of the HD video codec VP8 plays into the ongoing debate over which video codec browsers can use to display high-definition video without a plug-in, such as Adobe Flash or Microsoft Silverlight.
Google obtained the codec when it acquired On2 Technologies in February. Under the name of WebM, Google, along with other contributors, will maintain the source code, specifications and application programming interfaces of VP8.
Observers have noted that should Google release VP8 as an open standard, it could potentially solve the ongoing possible performance and legal issues surrounding other high-definition video codecs that could be used with the HTML5 standard.
Thus far, browser adoption of VP8 has been quick -- at least when market leader Microsoft is not factored in -- though performance concerns have arisen about the codec.
Both Opera and Mozilla have built test versions of their browsers that can run videos with the .webm suffix, as does a beta version of Google's own Chrome browser. Adobe has also pledged that Flash will be able to run VP8 video.
The Free Software Foundation has praised Google for putting VP8 into open source, a move that FSF had urged Google to make in February.
"The world would have a new free format unencumbered by software patents. Viewers, video creators, free software developers, hardware makers -- everyone -- would have another way to distribute video without patents, fees, and restrictions," Holmes Wilson wrote on the organization's site in February.
Technically speaking, however, video codec experts seem to be split over how well VP8 stacks up against the H.264 codec favored by Apple and Microsoft for HTML5 playback. They do seem to agree that the format does not hit the performance claims made by ON2.
In terms of compressing files, "VP8 appears to be significantly weaker than" H.264, wrote Jason Garrett-Glaser, one of the developers behind the x264 open-source library for rendering video into H.264, in a blog analysis. In his tests, VP8 decompression seemed to require more processing power as well.
Garrett-Glaser noted that these results are especially problematic because Google has finalized the specification and organizations such as Mozilla and Adobe have rushed to support it, which will make it difficult to make the changes needed to improve performance.
"It would have been better off to have an initial period during which revisions could be submitted and then a big announcement later when it's completed," he wrote.
Garrett-Glaser did note that VP8 performance is better than that of Ogg Theora, the other potential choice for Web video.
Streaming media consultant Jan Ozer also compared the performance of VP8 and H.264, and found the two to be about roughly equivalent, performance-wise.