MKV is the filename extension for Matroska Multimedia Container, an open-standard free container format. A Matroska file can hold a number of audio, video and subtitle streams, besides attachments like graphics and decoder filters all at the same time, thus allowing a complete movie to be stored in a single file.
Matroska was intentionally designed to be flexible so it could hold any kind of codec and be easily edited if need be. It consists of several well defined sections in the following order:
The Matroska file format is based on EBML (Extensible Binary Meta Language), a binary derivative of XML. This makes the file extensible, thus allowing more information to be encapsulated in the future as new developments take place, without breaking file support in the old parsers. Other characteristics of Matroska include high error recovery, in-file fast seeking, selectable audio and subtitle streams, streamable over the internet, and Menus (like those on DVDs).
- The Header defines the file type.
- The Metaseek gives an index of the locations of the different files.
- The Segment Information contains basic information, like the file title, ID, etc.
- The Track gives track information, like if its audio, video, etc., and what codec to use to view it.
- The Chapters lists the chapters defining the different points.
- The Cueing Data gives the index of all the tracks.
- The Attachment this section is for attaching files like pictures or web pages.
- Tagging contains all the tags to all the files and tracks, like singer, actor, director, and so on.
Matroska files, with the extension .mkv, may be opened with Matroska Splitter, Windows Media Player, MPlayer, VideoLAN VLC media player, Media Player Classic, Core Media Player, BS Player, Arpa Kolla player, NERO Show Time, Azureus Vuze Media Player, KMPlayer, Totem Movie Player, GOM Player, and Zoom Player.
MKV files can also be played on Palm, Symbian, and Pocket PC mobile devices using the CorePlayer Mobile software.