Streamline: What WebM Means for You
Posted Jul 16, 2010

The new streaming audio and video format known as WebM is actually old news—sort of. Yet it will have significant implications for video on the web, now and in the future.

WebM is a new format that Google has offered to the online video community, consisting of both an open source audio and video codec under the file extension .webm. So one major reason that we should sit up and take notice of this codec and expect it to play a significant role in the future of video on the web is because of its importance to Google. The video codec is the codec formerly known as On2’s VP8. On2 announced VP8’s availability in 2008, but it never saw the light of day in products that you or I could use, for a variety of reasons. VP8 has been billed as a replacement for H.264 from the very first announcement of the technology, a 2008 press release titled “On2 VP8 Surpasses H.264, VC-1, Real Video in Quality and Performance.” Until Google acquired On2 earlier this year, the codec had never been properly compared to H.264 to validate the claims. After the WebM format was released in May 2010, the claims of H.264 superiority received a few rapid independent tests, both of which bring the claims of superiority over H.264 into question. Expect additional, more substantial tests in the coming months to further explore the claims of the past 2 years.

Google expressed interest in the acquisition of On2 to gain access to the technology, which Google and the open source community needed in order to make a defensive move in the battle for browser video playback without a browser. To better understand this battle, we have to look at the audio codec. Ogg Vorbis, part of the Ogg project that also spawned the open source Theora video codec, does a decent job at audio compression.

Vorbis has been around for about 5 years, although it’s not nearly as popular as the mainstream MPEG-2 Layer 3 (MP3) or Advanced Audio Compression (AAC) audio codecs found in DVDs, Blu-ray Discs, MP3 players, and iTunes.

The video codec, Theora, on the other hand, was—by today’s standards—a horribly inefficient video codec, and understandably so. It was decade-old technology based on an open sourced version of On2 Technologies’ earlier VP3 codec, which itself was based on H.263—a standards-based videoconferencing codec—which was based on H.261 … well, you get the picture.

Because Ogg Theora was based on decade-old technology, the open source community had trouble getting buy-in from some browser manufacturers for Ogg technologies’ ultimate goal: replacing mainstream codecs within browsers and video players.

The draft specification for the next version of HyperText Markup Language (HTML) called for audio and video tags (with “” and “” as literal HTML tags) to be available as part of HTML5. The idea within the open source community was for audio and video playback to occur directly within in the browser, with no need for players such as Adobe’s Flash Player, Apple’s QuickTime, and Microsoft’s Silverlight.

The “” tag would launch Ogg Vorbis audio, the “” tag would launch Ogg Theora video, and the rest would happen seamlessly.

Except some browser manufacturers disagreed during the draft specification discussion. Some of the reasons against having Ogg Vorbis audio and Ogg Theora video defined as the de facto codecs for the “” and “” tags were based partly on technology and partly on adoption rates: H.264 had a significant quality advantage over Theora, as well as a significant market share.

In the end, the browser manufacturers were split on their decision to support Ogg versus H.264 video and AAC audio, so the tags were set up in such a way as to call particular video and audio codecs, depending on the browser.

This brings us back around to VP8. The door was left open during the draft specification discussion to designate the tags for discrete codecs if a better quality open source codec emerged. The VP8 technology acquisition by Google, followed by the release of the VP8 code under an open source BSD (permissive-free) license, means that the open source community may have the technological firepower to force Ogg Vorbis and VP8 into the default codec roles.

The one thing that Google did right in the release of WebM was to eliminate the older Ogg container as well as Theora and replace them with the newer Matroska container (the M in WebM) and VP8, respectively.

Regardless of whether VP8 becomes a default codec within HTML5-compliant browsers, Google’s launch of an open source alternative for cost-conscious video delivery will impact H.264 royalty rates.

In the end, it looks like we’ll have both the ability to encode WebM formats with traditional tools (support has been announced by major encoding and transcoding tool companies) and the ability to play back WebM files within a few distinct browsers, such as Mozilla’s Firefox. Consumers and content producers both win, as the WebM format provides a royalty-free way to deliver adequate web video and audio, once its own potential royalty issues are resolved.

Tim Siglin (writer@braintrustdigital.com) is chairman of Braintrust Digital, a digital media production company, and co-founder of consulting firm Transitions, Inc. He consults on digital media “go to market” strategies and also blogs on metadata issues at www.workflowed.com.