from Austin Meyer:
QuickTime files (*.mov, or *.qt) created with versions one and two of
QuickTime. (Versions three and four are not supported.)
•Audio Video Interleave (*.avi)
•Motion Picture Experts Group (*.mpg, *. mpeg, *.m1v, *.mp2, *.mpa, *.mpe)
•Microsoft Streaming Format (*.asf, *.asx)
•Animated GIF (*.gif) While animated GIFs are not movies, they come close
enough for discussion in this document. Note:
oOnly PPT2000 and later support animated GIFs
oYou insert GIFs using Insert, Picture, From File (rather than Insert,
Movie, From File)
oAs pictures, GIFs are always embedded unless you specifically choose to
link them (unlike other movie formats, which are always linked)
While other, less popular video formats exist, these are the most common and
most likely to be used in PowerPoint. Should you need to use one of the less
popular formats I strongly suggest converting it to an avi or mpg format.
Sounds:
•Audio Interchange File Format (*.aiff, *.aif, *.aifc)
•Motion Pictures Expert Group Layer-3 (*.mp3, *.m3u) (Note: May only be
inserted with PowerPoint 2000 but may be played back with PowerPoint 97 or
the 32-bit PowerPoint Viewer.)
•Musical Instrument Digital Interface (*.midi, *.mid, *.rmi)
•Unix Environment (*.au, *.snd)
•Microsoft Wave (*.wav)
•Microsoft Streaming Format (*.asf, *.asx)
•CDAudio (*.cda)