By Daniel Eran Dilger

Published: 01:30 PM EST (10:30 AM PST)

At its annual I/O conference, Google has unveiled its plan to release a video codec it acquired as a royalty free alternative to the ISO MPEG's H.264.

Google was joined by Mozilla and Opera as browser vendors that would be including support for the new codec, dubbed WebM. Mozilla's Firefox currently does not support H.264 because doing so would require purchasing a license from the ISO.

WebM is, as the name suggests, targeted at the web and not intended to replace H.264 across the board. As such, the project can be focused on a narrower set of engineering goals. WebM also supports HTML5 delivery of web video, as unlike H.264, it can be used to deliver web-based videos to any modern web browser, not just the commercial products of large companies like Apple's Safari, Google's Chrome, and Microsoft's Internet Explorer.

"The VP8 and WebM specifications as released on May 19th, 2010, are final," Google announced, "and we encourage everyone to use them for developing applications. Google, Mozilla and Opera are all adding WebM support to their browsers and all videos that are 720p or larger uploaded to YouTube after May 19th will be be encoded in WebM as part of its HTML5 experiment."

An open end for On2's proprietary codecs

The technology behind WebM was acquired by Google when it bought On2 Technologies, a company that had developed a series of proprietary codecs dating back into the early 90s. On2's TrueMotion technology began incrementing through a series of new codec generations including VP3, which On2 sold as a plugin for QuickTime, RealPlayer and Windows Media. It later released VP3 as open source in 2002. The free Ogg Theora codec was developed as a fork from the abandoned VP3 code.

Over the past decade, On2 rapidly grew past its old VP3 code to deliver VP4, which it licensed to RealPlayer and AOL; VP5, also used by Real; and VP6, which On2 licensed to China in 2003 for use in its national Enhanced Versatile Disc format as a rival to DVD (which uses the ISO's MPEG-2 video compression standard).

On2 also licensed VP6 to Macromedia in 2005, which made it the primary codec used by Flash Player 8. The successive VP7 codec was licensed to Skype for use in video conferencing. However, by VP7's release in 2005 the world had already began shifting toward open video codecs using a shared patent pool run by the ISO, leaving On2 to pit VP7 against H.264 in a losing battle. Before releasing VP8, On2 was bought up by Google this January.

The move towards open in video codecs

Apple shifted its resources from supporting proprietary codecs like Sorenson (once nearly synonymous with QuickTime in the 90s) toward the iSO's open MPEG technology starting in 2002 with QuickTime 6's support for MPEG-4 and mobile 3GPP video. In 2005, Apple began exclusively pushing the new H.264 with the release of QuickTime 7.

Microsoft had similarly decided to release its own competing Windows Media Video codecs as a published standard, known as VC-1. BluRay licensed both VC-1 and H.264, but Apple's leading position in selling audio and video content in iTunes has nudged global development towards H.264, which is now the most widely used modern codec stretching from mobile video to high definition playback.

The problem with H.264 is that while being an open specification, it's not free. Users have to license the technology from the ISO, which then distributes royalties to the companies who contributed their technology to improve the format. This is a problem for open source projects like Firefox, which don't want to spend money on licensing technology.

The VP-3 based Ogg Theora that Mozilla selected to support instead has serious drawbacks of its own however. While it is free, it's also much older and far less sophisticated than today's H.264 technology, which is still rapidly evolving. Additionally, the path to enhance Theora is littered with patent land mines, as many core video compression technologies are already patented by companies participating with the ISO's MPEG-4, VC-1, or using the patents in their own proprietary codecs.

WebM vs Theora: no contest

Another major problem for Theora is that common silicon doesn't support hardware decompression of Theora-encoded video. Nearly all video chips used in set top boxes or mobile devices now support H.264. This results in better performance and much better battery life for handheld products like smartphones, the iPod touch and iPad.

Google's new free codec, based on On2's unreleased VP8, solves some of the problems Mozilla faced with Theora. The technology is nearly a decade more modern, so it can be taken more seriously than the purely ideological Theora project. It also has the backing of Google, meaning it has both the potential to defend itself from patent attacks and may eventually find support from chip vendors.

Whether Google's new WebM codec will be widely supported on the desktop is not really an issue, as it will be trivial for Google or third parties to offer plugin codec support for QuickTime or Windows Media Player. The remaining problem is finding support for mobile devices such as the iPod, iPhone, and other maker's devices designed to support H.264 playback.

Most mobile and embedded devices can not be upgraded by third parties to support playback of alternative codecs, so even if Google and Mozilla convert lots of proprietary video (such as YouTube's Flash) into free WebM content, today's mobile devices won't be able to play it unless there's also an H.264 alternative available.

However, the new WebM codec should help small publishers deliver their content to desktop users without worrying about licensing costs. And at some point in the future, WebM may be viable on mobile devices if Google can convince chip makers to support the technology in their decoder components. The presence of WebM may also provide competitive pressure on the ISO and its pool of participating technology companies to keep MPEG-4 licensing reasonable for users.

Additionally, WebM further bolsters the move toward HTML5 for audio and video playback on the web, erasing the largest pillar holding up Adobe's Flash platform (even as Adobe rushes to support WebM as well within Flash). At the same time, even with a more modern alternative to Theora, Google may have some difficult in convincing Apple and Microsoft to get on board, given that both have already committed to supporting H.264, and neither see a problem with paying licensing royalties to the ISO.