Some corrections and additions

Changed "aac" to "audio/aac"
http://en.wikipedia.org/wiki/Advanced_Audio_Coding

Added "m4a" for "audio/mp4" and "m4v" for "video/mp4"
Commented out "mp4a" since the official extension is "m4a"
http://tools.ietf.org/rfc/rfc4337.txt
http://en.wikipedia.org/wiki/MPEG-4_Part_14

Added "3pg" for "video/3gpp"
http://tools.ietf.org/html/rfc3839#section-3.2

Added "3g2" for "video/3gpp2"
http://tools.ietf.org/html/rfc4393#section-3.2

Added "ogx" for "application/ogg"
http://tools.ietf.org/html/rfc5334#section-10.1