MP4

MPEG-4 Part 14

MPEG-4 Part 14 extends over ISO Base Media File Format (MPEG-4 Part 12).
Filename extension	.mp4, .m4a, .m4p, .m4b, .m4r and .m4v[Note 1]
Internet media type	video/mp4
Type code	mpg4
Developed by	International Organization for Standardization
Type of format	Media container
Container for	Audio, video and text
Extended from	QuickTime File Format and MPEG-4 Part 12
Standard	ISO/IEC 14496-14

MPEG-4 Part 14 or MP4 is a digital multimedia container format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only official filename extension for MPEG-4 Part 14 files is .mp4. MPEG-4 Part 14 (formally ISO/IEC 14496-14:2003) is a standard specified as a part of MPEG-4.

Some devices advertised as "MP4 Players" are simply MP3 Players that also play AMV video or some other video format, and do not necessarily play the MPEG-4 Part 14 format.

MPEG-4 Part 14 is an instance of the more general ISO/IEC 14496-12:2004 (MPEG-4 Part 12: ISO base media file format) which is directly based upon the QuickTime File Format. MPEG-4 Part 14 is essentially identical to the QuickTime file format, but formally specifies support for Initial Object Descriptors (IOD) and other MPEG features. MPEG-4 Part 14 revises and completely replaces Clause 13 of ISO/IEC 14496-1 (MPEG-4 Part 1: Systems), in which the file format for MPEG-4 content was previously specified.