What is WebM? VP8?VP8 is a video codec, like H.264, VP6, Theora, etc. WebM is two things: a container format (based on Matroska), and the name for an open-source video project. Presumably, WebM could contain other open video and audio codecs down the road.
Does Zencoder support VP8?Yes! We've been working with Google for the last few weeks to build VP8/WebM support into Zencoder. Try it out!
Where does VP8 come from?Before Google bought them, On2 was one of the few companies in the world that made proprietary video codecs. Most video and audio codecs are industry standards, combining patents from a few dozen companies. So MP3 audio, for instance, contains 100+ patents. Anyone can read the MP3 spec, but to implement an MP3 encoder, or to decode or encode MP3 audio, you have to license these patents. Conveniently, the patents are grouped together into a patent pool, so you only have to sign one license, not 50, in order to do something with MP3. But On2 was different. They were a commercial company that created their own video codecs, like VP6, VP7, and (now) VP8. And their codecs were pretty good; VP6 became a big deal on the web when Macromedia licensed it for Flash 7 and 8. At the time, it was a major step forward from H.263, the Flash 6 video codec. It was even _almost_ as good as H.264 for a little while, before H.264 encoder implementations matured. Overall, though, H.264 is a better codec than VP6. So when Flash 9 got H.264, the need for VP6 was diminished a bit. Not that it went away; it's still the second most watched video codec on the web (after H.263, not H.264, if you can believe that).
What's the deal with HTML5 video?Fast-forward a bit. HTML5 includes a
<video>tag, like an
<img>tag, which browsers will use to natively play video, without requiring a plugin (e.g. Flash Player or Sliverlight). But it doesn't specify a standard codec. Firefox and Opera backed Theora, an open source codec, but a generation or two behind the best video codecs available today. Theora is actually based on On2 VP3, which On2 released under a BSD-like license several years ago. Apple and Microsoft won't include Theora support in their browsers because it's worse than H.264, and because they're concerned about submarine patents. Safari and IE backed H.264, which is the best codec on the market, but not free. H.264 requires a license from MPEG-LA (who manages the patent pool). The terms aren't currently onerous; H.264 is free or cheap for most users, at least in 2010. But that could change down the road, and even if it doesn't, the folks behind Firefox and Opera don't want to use a patent encumbered codec for philosophical and pragmatic reasons. So at the moment, HTML5 video is at an impasse. Firefox and Opera won't support H.264, and IE and Safari won't support Theora. (Google Chrome, incidentally, supports both.)