.M4V File Extension
File TypeiTunes Video File
This file is saved in a binary format, which requires a specific program to read its contents.
MPEG-4 file extension used for videos downloaded from the Apple iTunes store; includes TV episodes, full-length movies, and music videos; similar to an .MP4 file, but may be copy-protected using Apple's FairPlay DRM copyright protection.
To play a protected M4V file, your computer must be authorized (using iTunes) with the account that was used to purchase the video.
Unprotected M4V files may be recognized and played by other video players by changing the file extension from ".m4v" to ".mp4."