Audio and Video File Extensions

In case anyone was wondering: A great overview of AV file format extensions. You know you wanted to know what a m2v was just as much as me.

MIT/~tbuehler on File Extensions

aac – A newer MPEG sound format.

ac3 – A Dolby-Digital encoded audio file. Used primarily in DVDs. Needs proprietary codec to play.

aif, aiff – Audio Interchange File. The Mac equivalent of wav, but it is cross platform as well.

asf – Advanced Streaming Format. The original file extension for Windows Media files, this extension refers to both audio and video files. The confusion this caused lead to Microsoft abandoning this extension in favor of wma and wmv.

avi – Audio-Video Interleaved. One of the most common video files.

divx – Some DivX encoders and applications give the option of using the divx file extension for DivX encoded files. The files are exactly the same as those with the avi extension, with the only difference being that they have substantially worse compatibility (many applications that can play and import DivX encoded avis do not work with files that have the divx extension). Needless to say, the extension is pointless and you shouldn’t use it.

dv – Raw DV stream. Not commonly used, since most raw DV streams use an avi or mov extension.

m1v – An elementary MPEG-1 video stream. Cannot contain audio.

m2p – MPEG-2 program stream.

m2v – An elementary MPEG-2 video stream. Cannot contain audio. Requires MPEG-2 codec (commonly acquired with DVD player software) to playback. Most professional DVD authoring packages require m2v files.

mov, moov – Quicktime movie.

mpa – An elementary MPEG-2 audio stream.

mpg, mpeg – A multiplexed (audio and video combined) MPEG-1 or MPEG-2 file (although most commonly MPEG-1).

mp1 – MPEG audio, layer 1.

mp2 – MPEG audio, layer 2.

mp3 – The ubiquitous audio format that we all know and love. It is actually called “MPEG audio, layer 3″ and, as the name implies, intended to encode the audio portion of MPEG-1 movies.

mp4 – MPEG-4 movie (although MPEG-4 movies can also be avi or mov). Some people claim that mp4 is a new version of mp3. These people are idiots.

mpv – See m2v.

ogg – Ogg Vorbis audio file.

ogm – Ogg Vorbis video file.

omf – A video format developed by and used primarily by Avid editing systems, but has been adopted by other professional video applications and has become a high-end standard. Usually these files are not playable from the desktop but rather only inside the applications that use them. Stands for “Open Media Format.”

qt – Quicktime movie.

rm – Real video file.

ram – Real audio file.

swf – Macromedia Flash animation file.

vob – Video object file. Used in DVDs. Contains MPEG-2 video and several possible audio formats, as well as menus and interactivity.

wav – Microsoft wave audio file. PCM (pulse code modulation) audio, usually uncompressed.

wma – Windows Media audio file.

wmv – Windows Media video file.