Standards: Appendix E - File Extensions Vs. Container Formats

This list of file container formats and their extensions is not exhaustive but it does describe the important ones whose standards are in everyday use in a broadcasting environment.

This is an Appendix to our series of articles on Standards.

Container formats such as AVI, MKV, MXF, QuickTime or MP4 can carry a variety of differently coded video and audio which is not apparent from their file extension. Open the file and inspect the headers to determine what the file actually contains. In a few rare cases, an alternative file extension can be used to indicate the content format. Some applications will be able to open these files but will not be able to render the content as they lack the codec support.

Extension Format
3g2 3GPP2 mobile file
3gp 3GPP mobile file
aac AAC coded audio
ac3 Dolby AC3 surround sound file
aiff Audio Interleave File Format extracted from a CD
alac Apple Lossless Audio Codec
ape Monkey Audio file
asf Advanced Systems Format (alternative to wmv)
avi Audio Video Interleave
caf Apple Lossless Audio (ALAC) files (uncommon)
divx DivX Media Format
dts Digital Theatre Systems sound file
evo Enhanced VOB
f4v Flash Video file with H•264 video & AAC audio
flac Free Lossless Audio Codec (FLAC) coded audio
flv Flash Video file containing SWF encoded content. Deprecated and should not be used for new projects
m2p MPEG program stream (Prefer this to using ps)
m2ts BDAV MPEG-2 transport stream
m4a MPEG-4 audio file
m4b Audiobook and podcasts
m4p MPEG-4 audio file containing AAC audio which is DRM protected by Apple FairPlay
m4r Apple iPhone ringtones
m4v MPEG-4 Part 14 video file (alternative to mp4)
mk3d Matroška containing stereoscopic 3D video
mka Matroška audio
mks Matroška subtitles
mkv Matroška video
mov QuickTime File Format
mp3 An MPEG file containing only a MPEG-1 Audio Layer 3 audio stream
mp4 MPEG-4 Part 14 (generic alternative to m4v)
mpc Musepack audio file
mpeg See mpg
mpg MPEG-1 or 2 video/audio
mts Blu-ray BDAV MPEG-2 transport stream
mxf Material Exchange Format
ofr OptimFROG lossless coded audio
oga Ogg audio file
ogg Ogg audio/video file
ogm Ogg media file
ogv Ogg video file
ogx Ogg multiplexed media files
opus An Ogg format container containing Opus coded audio
ps MPEG program stream (Do not confuse these with raw PostScript print stream files)
qt Early QuickTime File Format (rarely used now)
rmvb Real Media Variable Bitrate file
ts DVD MPEG transport stream
tsv MPEG transport stream
vob DVD Video Object
wav WAV audio file. These are often used in radio broadcasting
wave See wav
webm Web Media is based on the Matroška format
wmv Advanced Systems Format (for Windows Media)

 

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