Multimedia type recommendations for HTML5 export

All Web browsers don’t support the same multimedia types, it is therefore required to provide media files in multiple encodings to ensure proper running on all main browsers.
Warning: multimedia file transcoding can lead to a loss in quality. When doing so, it is crucial to choose carefully the software and settings used.

These recommendation will concern the following browsers on their last version (27 august 2014):
- Chrome/Chromium
- Safari
- Firefox
- Internet Explorer (IE)
- Opera (not supported yet)

Audio

MP3 and ACC supported by all except Firefox GNU/Linux and Mac (need a third party library)
OGG Vorbis and WAV supported by all except IE
WebM (Vorbis / Opus) and OGG Opus supported by all except IE and Safari

Recommended :
MP3 + OGG Vorbis

Video:

H.264 (mp4) supported by all except Chromium and Firefox (Mac)
Theora (ogg) supported by Firefox, Chrome and Chromium
VP8/VP9 (WebM) supported by Chrome, Chromium and Firefox (Opera?)
MOV (QuickTime) isn’t supported by any browser.