History

• MP4 derives from an original ISO standard known as MP4 part 12. The official name of the MP4 specification is MP4 part 14. This original specification was highly based on the QuickTime MOV file format. MP4 part 14 adds several features to the original specification that allow for a rich media environment during playback. The initial release date of this specification is 2003. MP4 in and of itself is not a video encoding specification.
  
  

MP4 container

• MP4 is a media container format. Video streams that are encoded by other algorithms, such as Divx, are placed inside the MP4 file container. This allows for easy file extension recognition despite disparate codec implementations. There is no MP4 video codec and the playback of an MP4 file requires the use of the original codec used to encode the digital media. This is similar to the AVI file extension that requires a codec to decode the video data held within the AVI file container.
  
  

Features

• MP4 supports Advanced Audio Coding audio compression capabilities through the AAC audio codec. The MP4 extension also supports native subtitle tracks under the Timed Text ISO specification. This allows for subtitles that are not hard coded into the video stream itself, which allows editing and removal at a later point. MP4 also allows DVD menu meta data to be placed within the container format, a feature not commonly associated with single file video streams.
  
  

Support

• The software required to use MP4 video containers varies by platform. Computer users are required to download a standard MP4 reader pack if it is not present. This software is standard with many media players such as VLC media player. MP4 devices exist as private movie viewers for travel and convenience. Compatibility with these hardware devices requires that a suitable encoding algorithm be used prior to placement of the file into the MP4 format.