What is Matroska?

Matroska aims to become THE standard of multimedia container formats. It was derived from a project called MCF, but differentiates from it significantly because it is based on EBML (Extensible Binary Meta Language), a binary derivative of XML. EBML enables the Matroska Development Team to gain significant advantages in terms of future format extensibility, without breaking file support in old parsers.

What is a container?

First, it is essential to clarify exactly "What an Audio/Video container is", to avoid any misunderstandings:

  • It is NOT a video or audio compression format (video codec)
  • It is an envelope for which there can be many audio, video and subtitles streams, allowing the user to store a complete movie or CD in a single file.


Matroska is designed with the future in mind. It incorporates features you would expect from a modern container format, like:

  • Fast seeking in the file
  • Chapter entries
  • Full metadata (tags) support
  • Selectable subtitle/audio/video streams
  • Modularly expandable
  • Error resilience (can recover playback even when the stream is damaged)
  • Streamable over the internet and local networks (HTTP, CIFS, FTP, etc)
  • Menus (like DVDs have)

An open project

Matroska is an open standards project. This means for personal use it is absolutely free to use and that the technical specifications describing the bitstream are open to everybody, even to companies that would like to support it in their products. The source code of the libraries developed by the Matroska Development Team is licensed under GNU L-GPL. In addition to that, there are also free parsing and playback libraries available under the BSD license, for commercial software and Hardware adoption.


The Matroska has the following goals:

  • Create and document a modern, flexible and cross-platform Audio/Video container format, in combination with an open codec API to form a free and open media framework
  • Establish Matroska as the opensource alternative to existing containers such as AVI, ASF, MOV, RM, MP4, MPG ES
  • Develop a set of tools for the creation, editing and implementation of Matroska files
  • Develop libraries and tools for software developers to be able to support Matroska in their applications
  • Prepare hardware support of Matroska files in next generations standalone units, in close cooperation with device manufacturers
  • Support adoption and implementation of Matroska's in open architectures like FFmpeg, VLC or GStreamer (Multimedia Framework for Linux, equivalent to Microsoft (TM) DirectShow (R) for Windows (TM))
  • Launch a set of DirectShow filters for playback and creation of Matroska files on Windows (TM) Operating Systems


We invite every interested developer to join our team and to help us to achieve these goals. While most of the existing Matroska code is in C++ we are also interested in C and Java programmers joining us.