HTML and CSS Reference
Table 8.5. Browser video and audio format support
As you can see, no single format is universally adopted across all browsers. For broad
desktop support, you need to provide at least two versions of your media: for video at least
WebM/VP8 and MPEG-4/H.264, for audio MP3 and OGG.
Media format support is something of a contentious issue in the HTML5 world. The sidebar
“ Why doesn't HTML5 mandate a format that all browsers support? ” explains why.
Why doesn't HTML5 mandate a format that all browsers support?
Initially, the HTML5 specification mandated the Ogg/Theora video format. This seemed
like a good choice because it's an open source format and the codec is royalty free. But
Apple and Microsoft refused to implement Ogg/Theora, preferring instead the MP4/h.264
combination. MPEG LA, LLC, administers MP4/h.264 and sells licenses for encoders and
decoders on behalf of companies that hold patents covering the h.264 codec. (Apple and
Microsoft are two such companies.)