Initially Mozilla took a firm stance when it came to HTML5′s video tag – only open-source video codecs are welcome, proprietary stuff like h.264 will not be supported. Now however, their position has softened – Firefox will support whatever media codecs the host OS has in addition to Theora (which was there from the start).
The change will first be implemented in their experimental Boot 2 Gecko mobile OS (which we saw in action at the MWC) and later added to the Android version of Firefox. Desktop Firefox might prove a bigger challenge, however.
Andreas Gal, Mozilla’s director of research, himself is working on the HTML5 video support. It will work with codecs already present on the system, including hardware acceleration (which is critical for mobile devices).
The concern over HTML5 video is that it might cause fragmentation – browsers like Firefox and Opera wanted only open-source video to be supported by the standard, while Microsoft insisted on the proprietary h.264 format and Google decided to just support all (they even created their own video format).
Fragmentation is still an issue – Windows 7 comes with a licensed h.264 decoder, while Windows XP does not. And Mozilla pride themselves in supporting XP with their new browsers, something even Microsoft doesn’t do anymore.
You can follow the discussion on how Firefox will support HTML5 video over here.