DivX Media Format (DMF)

The latest generation, DivX 6, was released on June 15, 2005 and expands the scope of DivX from including just a codec and a player by adding a media container format. This optional new file format introduced with DivX 6 is called "DivX Media Format" (or "DMF" for short) (with a .divx extension) that includes support for the following DVD-Video and VOB container like features.

DivX Media Format (DMF) features:

Interactive video menus
Multiple subtitles (XSUB™)
Multiple audio tracks
Multiple video streams (for special features like bonus/extra content, just like on DVD-Video movies)
Chapter points
Other metadata (XTAG™)
Multiple format
Partial backwards compatibility with AVI

This new "DivX Media Format" also came with a "DivX Ultra Certified" profile, and all 'Ultra' certified players must support all "DivX Media Format" features. While video encoded with the DivX codec is an MPEG-4 video stream, the DivX Media Format is analogous to media container formats such as Apple's QuickTime. In much the same way that media formats such as DVD specify MPEG-2 video as a part of their specification, the DivX Media Format specifies MPEG-4-compatible video as a part of its specification. However, despite the use of the ".divx" extension, this format is basicaly the AVI file format by another name. The methods of including multiple audio and even subtitle tracks involve storing the data in RIFF headers and other such AVI hacks which have been known for quite a while, such that even VirtualDubMod supports them. DivX, Inc. did this on purpose to keep at least partial backwards compatibility with AVI, so that players that do not support the new features available to the .divx container format (like interactive menus, chapter points and XSUB™ subtitles) they can at least play that primary video stream (usually the main movie if the .divx contain multiple video streams like special features like bonus materials). Of course, the DivX codec and tools like Dr.DivX still support the traditional method of creating standard AVI files.