From Just Solve the File Format Problem
Matroska Audio (.mka) files consist of a Matroska container containing one or more audio files compressed with one of the supported codecs. As well as the compressed audio, a Matroska Audio file might also contain embedded lyrics or transcriptions, in the form of SRT subtitles. In addition, Matroska Audio files can be separated into tracks or chapters - it is possible, for example, to contain a whole album or audiobook in a single file while retaining clear separation between tracks.
|Matroska||fdd000342||Refer to Matroska.|
|Matroska with LPCM Audio Encoding||fdd000346|
|Matroska with MP3 Audio Encoding||fdd000347||Refer to MP3.|