HTML and CSS Reference
Firefox, Opera, and Chrome do support another codec, Theora, from the same organization
(Xiph.Org) that provided the Ogg container and Vorbis audio codec described in the last sec-
tion. The Ogg Theora container/codec was originally the mandatory codec and container for
video elements in HTML5 until Apple and other companies objected to the restriction. Neither
IE nor Safari support Ogg Theora, though there are plug-ins that can be installed to provide
support in both browsers.
Xiph.Org provides a plug-in that enables support for the Theora and Vorbis codecs in QuickTime,
which indirectly enables support for Safari. Access the plug-in at http://www.xiph.org/quicktime/
Theora, WebM, and various other Ogg container/codec pairings, and can be accessed at ht-
The last video container I'll cover is WebM, which I introduced in the section on audio codecs.
Unlike many of the other containers, WebM supports only one audio codec, Vorbis, and one
video codec, VP8. VP8 was created by a company named On2, which was later bought by
Google—who promptly open-sourced the VP8 codec.
WebM is supported by Chrome, Firefox, and Opera. There is no built-in support for WebM in
Safari and IE, but, as mentioned earlier, there is plug-in support for WebM for both browsers.
Since Chrome, Firefox, and Opera support both Ogg Theora and WebM, which should you
use? The answer is: it depends.
Both should continue to be supported for the foreseeable future. The Open Source community,
including Wikipedia, still primarily support Ogg Theora, but since Google open-sourced VP8,
this may change in the future. VP8 is generally considered a better codec than Theora, but
I've never seen much difference in quality when it comes to videos sized and optimized for
the web. But then, I'm not a picky videophile, either.