MPEG-4 confuses me

[Syro]

I'm trying to understand this whole MPEG-4 thang...:

- what's the difference between .MP4 and .M4V files?
- which one does the video iPod use and which one does the PSP use?
- is H.264 a thing of .MP4 (or .M4V) files like DivX and XviD are things of .AVI?
- is there a difference between DivX/XviD, MPEG-4 and these .MP4 and .M4V files?

[yoda313]

check out the glossary on this website:

https://www.videohelp.com/glossary

has many defintions for you

[Alex_ander]

MP4 FAQ:
http://forum.doom9.org/showthread.php?s=&threadid=62723

[celtic_druid]

In terms of MPEG-4 an m4v file is the extension for raw MPEG-4 Part 2 video stream. In apple terms it is just a renamed mp4. mp4 is the only official extension. m4a, m4v, m4p, etc. were made up by Apple.

iPod and PSP both use mp4, although you may require some custom Atoms (I read somewhere that the PSP doesn't any more, but iTunes does now to upload 640x480 AVC encodes).
You can store H.264 streams in mp4 or many other containers (including avi). The extension for a raw stream (equiv of m4v) would be .264. Xvid and DivX can also be stored in mp4.

DivX/Xvid are part 2 of the standard, mp4 is part 14.

Some/All of the above would be covered in the above links.

avi has nothing to do with MPEG-4.