HTML and CSS Reference
In-Depth Information
Table1-2.Audio container/codec support across popular modern browser versions
Container/Co-
dec
Type
Extension(s) IE9+ Firefox Safari
5+
Chrome Opera
11+
WAV
audio/wav or audio/
wave
.wav
No
Yes
Yes
Yes
Yes
MP3
audio/mpeg
.mp3
Yes
No
Yes
Yes
No
Ogg Vorbis
audio/ogg
.ogg, .oga
No
Yes
No
Yes
Yes
MPEG-4 AAC
audio/mp4
.m4a
Yes
No
Yes
Yes
No
WebM Vorbis
audio/webm
.webm
No
Yes
No
Yes
Yes
HTML5 Video Element Codecs/Containers
As I mentioned in the last section, video files are far too large to serve up in anything other
than a lossy compressed format. As with audio codecs, no one video codec works in all
browsers.
H.264
One of the most popular lossy video codecs is MPEG-4 Part 10, commonly known as H.264.
H.264 is a high quality, popular format that's common on the Internet and supported in
YouTube and iTunes. It is also one of the three mandatory codecs supported by Blu-Ray play-
ers. It's a mature codec, first standardized by the MPEG group in 2003. H.264 is also a con-
troversial choice because of the patents held on the codec by the organization, MPEG-LA.
Though video files encoded in H.264 that are distributed without cost aren't subject to royal-
ties, tools that encode or decode H.264 do have to pay royalties. The cost for these royalties is
usually passed on to the tool buyer.
The H.264 video codec is combined with either the AAC or MP3 audio codec in an MPEG-4
container. This combination is typically known as MP4, and files are usually given an .mp4
extension . You'll also see files with .m4v extensions for H.264. Apple iTunes uses the .m4v
extension with its videos, but they're also encumbered by DRM and won't play in HTML5
video elements.
The H.264 codec is the only video codec that Microsoft supports for IE. It's also supported by
Safari. Chrome has dropped support for H.264, and Firefox and Opera have never supported
it because of the patent issues.
