Extensions for video files
Word of warning: it is a common (and very annoying) practice on file sharing networks to rename the file extensions to different extensions*. This is of little consequence in most cases, since many media players go by file header instead of extension, but when an unusual file format or codec is encountered it greatly complicates the task of identifying it. Therefore, don’t entirely count on file extensions for identification, but when in doubt, use instead the more reliable file identification tools. Thus this should only serve as a vague guide.
mpeg = motion pictures experts group
mpg, mpe, mpeg - mpeg-1 or mpeg-2
m1s - usually mpeg-1 video without audio
mpa, mp2, m2a - usually mpeg audio without video
mp2v, m2v, m2s - usually mpeg-2
avi = audio-video interleave
mov - quicktime movie
qt - quicktime movie
asf - active streaming format (or advanced systems format)
asx - active streaming format shortcut
wmv - windows media video
wma - windows media audio
wmx - windows media shortcut
rm - real media
ra - real audio
ram - real audio/media shortcut
rmvb - real media variable bitrate
mp4 = “ISO compliant MPEG-4 streams with AAC audio”
3gp = 3gpp (“3rd Generation Partnership Project”)
ogm = ogg media
mkv = matroska
* Why would people do that? For various reason. The most obvious to me is the insertion of advertisement or popups (very common in wmv files renamed to mpg or avi).
** Windows Media is Microsoft’s own proprietary format. One may wonder if differences exist between asf and wmv files. From my experience the asf extension has been associated with the older NetShow codecs (Duck TrueMotion, VDOWave, ClearVideo, Vivo H.263, MS H.263, MS MPEG-4 v1, v2, and v3), while the wmv extension has been associated with the newer Windows Media codecs (Microsoft ISO MPEG-4 v1 and v1.1, Windows Media Video 7, 8, 9, Windows Media Screen 7 and 9). Use for Microsoft’s MPEG-4 v3 has been ambiguous. Also it appears wmv files have a few additional features to them which the old asf files didn’t have, notably the ability to generate popups, and the presence of DRM (digital rights management). Finally the older asf files generated by NetShow Tools and Windows Media Tools can be transcoded (switch container) from asf to avi using asftools or virtualdub 1.3c, whereas the newer files made with Windows Media Encoder 7.1 and 9 can’t.
don’t need any codec for playing that file? AVI format, don’t worry about this video files type, you should try mplayer., all in one.
what do i do if quick time is not working on a .mov file?what other options do i have to play the .mov?
What is the most common file extension? I have a VOB that won’t open or play on my computer. What should I convert it to?
Aha, Great Job!
More Multimedia File Extensions Glossary.
how do i play .video files downloaded from skyplayer desktop without actually using skyplayer desktop... i have converted it to .mp4 with skuld ipod converter and it was just a green screen with no sound, played it with any video converter and it was the same... any advice?
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