ISO base media file format

It is designed as a flexible, extensible format that facilitates interchange, management, editing and presentation of the media.

The file format is designed to be independent of any particular network protocol while enabling support for them in general.

A list of all registered extensions for the ISO base media file format is published on the official registration authority website, www.mp4ra.org.

[34] The registration authority for code-points (identifier values) in "MP4 Family" files is Apple Inc., and it is named in Annex D (informative) in MPEG-4 Part 12.

If an existing specification already covers how a particular media type is stored in the file format (e.g., MPEG-4 audio or video in MP4), that definition should be used and a new one should not be invented.

[9] MPEG has standardized a number of specifications extending the ISO base media file format: The MP4 file format (ISO/IEC 14496-14) defined some extensions over the ISO base media file format to support MPEG-4 visual/audio codecs and various MPEG-4 Systems features such as object descriptors and scene descriptions.

Storage of MPEG-1/2 Audio (MP3, MP2, MP1) in the ISO base media file format was defined in ISO/IEC 14496-3:2001/Amd 3:2005.

[42][43] The OMA DRM Content Format (.dcf) specification from Open Mobile Alliance defined the content format for DRM protected encrypted media objects and associated metadata.

[34] There are some extensions of the ISO base media file format that were not registered by the MP4 Registration authority.

The F4V file format was not registered by the MP4 registration authority, but the F4V technical specification is publicly available.

[55] Microsoft published a Protected Interoperable File Format (PIFF) specification in 2010.

It defined another usage of multiple encryption and DRM systems in a single file container.

The "box" is an object-oriented building block defined by a unique type identifier and length.

It is somewhat analogous to the so-called fourcc code, used for a similar purpose for media embedded in AVI container format.

In that case, they should be read as if they contained an ftyp with a major and compatible brand "mp41" (MP4 v1 – ISO 14496-1, Chapter 13).

Existing media can be easily made streamable for other specific protocols by the addition of appropriate hint tracks.

The streams sent by the servers under the direction of the hint tracks, need to contain no trace of file-specific information.