Matroska

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Matroska, according rus. Matryoshka, is a container format for audio and video data. Matroska files have either the extension. Mkv video data or. Mka for audio data. For the ending subtitles. Mks is used while mk3d was introduced for three-dimensional content the ending..

Matroska supports various video codecs, including MPEG -1, MPEG -2, MPEG -4, H.264, Real Video, WMV, Theora, Dirac, and audio codecs, such as AAC, AC3, DTS, WAV, MP3, Vorbis and FLAC as well as additional formats for subtitles ( VobSub ) and extended meta information.

The developers understand the format as an alternative to existing container formats like AVI, OGM / Ogg, ASF, MOV or MP4. The specifications can be viewed publicly and can be freely used in software applications. The core libraries are available under the GNU LGPL, the parser under the BSD license.

Properties of the format

The format used EBML, a binary XML format, to describe the container. This is a high flexibility of the format allows, while ensuring that further developments of the format can be read by older parser yet.

Similar to DVDs, the Matroska specification allows, inter alia, the division of files into chapters, seamless branching, and the use of multiple audio tracks, for example, for different language versions. The aspect ratio can be changed during output. The standard also provides for menu functions for user management; a corresponding implementation there but so far neither the authoring tools still in the playback software.

Matroska container, in addition to audio and video streams also contain text (eg for subtitles ) files or any other format. The frame rate of the video stream need not be constant, but may vary (variable frame rate encoding, VFR). The synchronization of audio and video tracks can be retrofitted even by adjusting the meta information with an appropriate shift in the creation as well.

Matroska files are often smaller than similar files in other formats, because the data structure of the container produces only a small overhead. The maximum file size in bytes of the current specification, corresponding to 72 bytes or PB.

Matroska can be used as a streaming format and then transmitted via HTTP - RTP streaming via is not recommended.

Dissemination

DivX, Inc. uses for its published in January 2009, DivX 7 MKV format as the only container format, but not in a fully standards- compliant implementation.

In May 2010, Google announced the WebM multimedia format free as an Open Source project, which is based on the freely purchased video codec VP8, the free Vorbis audio codec and a simplified variant of Matroska. It provides only a simplified file structure and allows only the codecs VP8 video and Vorbis for audio tracks.

Support MKV to hardware devices

Are supported in the main MKV files to the video codecs H.264 Level 4.0 and 4.1, MPEG -4 ASP (Advanced Simple Profile ) and audio tracks in formats AC3, MPEG -1 Layer 2 (MP2 ) and Layer 3 ( MP3), Advanced Audio Coding (AAC ), and Ogg Vorbis. However, it is not easily possible to help them in all possible MKV videos in hardware, due to the enormous variety of possible video and audio streams in MKV files. Defined playback profiles, so-called subset of Matroska, which would allow this simple, yet lacking in the standard.