HTML and CSS Reference
hope at the time the media elements were first defined was that this tower of babble that we
have for audio and video could be avoided by ensuring support for one container and one co-
dec, neither of which are encumbered by patents or royalty requirements.
Find out more about the Ogg Vorbis container/codec at the official support site at ht-
Apple and other companies, though, objected to the Ogg Vorbis requirement because of lack
of hardware support, their belief that the Vorbis codec was inferior to other codecs, and con-
cerns of potentially hidden patents (known as submarine patents) related to the codec.
Though the Xiph.Org foundation has done their best to search among patents to ensure Vorbis
is patent free, there's no way to guarantee that unless it is challenged in a court of law. It's a
catch-22 situation without any viable solution, so the section in the specification that required
support for Ogg Vorbis was removed.
For an interesting historical perspective, the email from Ian Hickson, HTML5 editor, about dropping
support for both Ogg Vorbis and Ogg Theara can be found online at http://lists.whatwg.org/pipermail/
Though Ogg Vorbis is no longer a requirement, several browsers do support it. Firefox, Opera,
and Chrome support Ogg Vorbis, while Safari and IE do not.
The AAC Codec
The Advanced Audio Coding (AAC) lossy compression codec was originally considered to
be a successor to MP3, though it didn't get broad acceptance. It languished, little known, until
Apple picked it as the format for the files in its iTunes store. The container it's most used with
is the MPEG-4 Part 14 container, known as MP4 for the .mp4 file extension. Though most
of us assume that MP4 files are video, they can be audio only. In fact, another common file
extension used with MP4 audio files is .m4a, again primarily because of Apple's influence.
Safari, Chrome, and IE support MPEG-4 AAC.