ISO Base Media File Format

Latest revision as of 20:58, 17 July 2023

ISO Base Media File Format (sometimes abbreviated BMFF or ISO BMFF) is a metaformat for "time-based" media formats (mainly audio and video). It is based on the more-general metaformat we're calling boxes/atoms format.

It is defined by Part 12 of the MPEG-4 standard, and also by Part 12 of the JPEG 2000 standard.

Files (almost) always have an "ftyp" box, containing a list of "brands" that give information about the specific file format. See the boxes/atoms article for more about brands.

Much of the format was copied from QuickTime format.

Among the formats based on it are MP4 and MJ2.

[edit] Identification

There appears to be no simple way to distinguish BMFF from other formats.

A file in boxes/atoms format that has both an "ftyp" box and an "moov" box probably uses a BMFF-based format. However, for compatibility with certain older files, the "ftyp" box can sometimes be omitted if the brand would be "mp41".

A BMFF file may (or may not) be labeled with one or more of the generic BMFF brands: "isom", and "iso[2-9]".

Note that some formats use an "ftyp" box, without being conformant with BMFF (though they may borrow elements from it). An example is JP2.

[edit] Specifications

• ISO Publicly Available Standards ...
  • ISO/IEC 14496-12:2015 PDF (archived)
  • 14496-12
  • 15444-12

[edit] Software

• ISOBMFF C++ library

For media players, etc., refer to the article for the relevant application format.

[edit] Links

• Wikipedia article