Well, I have collected almost, all well-known Audio and Video file format extension list at this blog. If I miss any format extension do comment, so that I can update it as soon as possible:
3GP Files (*.3gp;3g2)
AAC Files (*.aac)
AIFC Audio Files (*.aifc)
AIFF Audio Files (*.aif;*.aiff)
AUD Audio Files (*.aud)
AVI Files (*.avi)
Bink Vido Files (*.bik)
CAF Audio Files (*.caf)
CUE Files (*.cue)
DV Files (*.dv;*.dif)
Flac Audio Files (*.flac)
Flash Video Files (*.flv;*.swf;*.f4v)
JVC Recorded MOD Files (*..mod)
M4A Files (*.m4a)
M4B Audio Files (*.m4b)
Media Center Files (*.dvr-ms)
MJPEG Files (*.mjpg;*.mjpeg)
MKA Audio Files (*.mka)
MKV Files (*.mkv)
Monkey's Audio Files (*.ape)
MPC Audio Files (*.mpc)
MPEG Audio Files (*.mp3;mp2)
MPEG Files (*.mpg;*.mpeg;*.mpeg2;*.vob;*.dat)
MPEG HD Files (*.mp4)
MPEG2 HD Files (*.mpg;*.mpeg)
MPEG4 Files (*.mp4;*.m4v)
MPV Files (*.mpv)
MXF Files (*.MXF*.mxf)
Ogg Audio Files (*.ogg)
OGM Files (*.ogm)
OGV Files (*.ogv)
QCP Audio Files (*.qcp)
Quick Time Files(*.mov)
Raw AC3 Files (*.ac3)
Real Audio Files (*.ra;*.ram)
Real Media Files (*.rm;*.rmvb)
SUN AU Audio Files (*.au)
TOD Files (*.tod)
Video Transport Stream Files (*.ts;*.trp;*.tp)
WAV Files (*.wav)
WebM Files (*.webm)
Windows Media Files (*.wmv;*.asf)
WMA Files (*.wma)
WMV HD Video Files(*.wmv)
WTV Files (*.wtv)
