M4V Codec

M4V video files containers are produced by Apple for iTunes TV episodes, music videos, and feature length movies. The M4V file format is a standard file format for videos for iPods and PlayStation Portables developed by Apple. The  M4V files format is based on the MPEG-4 AVC video codec, which is a global media standard with the aim to provide optimized video podcasts for the video iPod. .M4V files are related to .MP4 files, however M4V files are opened with the iTunes player by default while MP4 files are opened with Quicktime player by default. 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, in some cases unprotected M4V files may be recognized and played by other video players by changing the file extension from ‘.m4v’ to ‘.mp4’.