‘M4V is a file container format used by Apple’s iTunes application. The M4V file format is a video file format developed by Apple and is very close to MP4 format. The differences are the optional Apple’s DRM copyright protection, and the treatment of AC3 (Dolby Digital) audio which is not standardized for MP4 container.
Apple uses M4V files to encode TV episodes, movies, and music videos in the iTunes Store. The copyright of M4V files may be protected by using Apple’s FairPlay DRM copyright protection. To play a protected M4V file, the computer needs to be authorized (using iTunes) with the account that was used to purchase the video. However, unprotected M4V files without AC3 audio may be recognized and played by other video players by changing the file extension from ‘.m4v’ to ‘.mp4’.
Besides Apple iTunes and Apple QuickTime Player, M4V files can also be opened and played with the version of Windows Media Player included with Windows 7, Media Player Classic, RealNetworks RealPlayer, VideoLAN VLC media player and Nero Showtime (included with Nero Multimedia Suite). The format, with DRM removed, can also be played in the webOS Video Player for use on the Palm Pre, Palm Pixi smartphones. It is also playable by the Android operating system with its video player. It can also be played with the BS Player Pro.
M4V video with FairPlay attached to it is read in QuickTime as AVC0 Media.