Last modified: 2008-12-15 19:31:03 UTC
http://wiki.xiph.org/index.php/MIME_Types_and_File_Extensions#.ogg_-_audio.2Fogg Xiph.org now recommends using extensions other than .ogg to make audio and video content easier to identify: .oga for audio, .ogv for video, and .ogx for multiplexed logical bitstreams (intended as a catch-all replacement for .ogg; the standards say .ogg should now be used for Vorbis I only for backwards compatibility with media players). Wikimedia's CommonSettings.php already contains a line "$wgFileExtensions[] = 'ogv';"; corresponding lines should be added for .oga and .ogx.
Since we only support Vorbis and Theora currently, sticking with .ogg and .ogv covers all supported upload types. .oga should be used for *non*-Vorbis audio, while .ogg should continue to be used for Vorbis audio for compatibility. .ogx could be anything, and won't be supported by our players.