Matroska is a multimedia container widely know for it's video format (mkv). Lesser known are the audio (mka) and subtitles (mks) formats. Also the stereoscopic/3D format (mk3d). Aside from being open and royalty-free, why are these formats interesting?
Tools
MKVToolNix is a CLI (optional GUI) tool to work with Matroska files. It works with mkv and mka, which are the two formats I tested. It's a single tool to work with both audio and video formats.
Features
Matroska is a do-it-all "universal" container that does many things well. The most interesting being:
- Chapters. For an audio file that means an entire album or audiobook can be contained in a single large mka file splitted by chapters, similar to m4b files. It's easy to make such a file in mkvtoolnix, would save me a lot of time from picking every ogg chapter file in librivox recordings.
- Multiple streams. A single file can hold different codecs (e.g. vorbis, opus and MP3) or different bitrates and they can be muxed from a supported player. Video players commonly support it whereas I am not aware of audio players with this feature.
- Subtitle embedding. Closed captions are popular in mkv, but mka could also hold an entire timestamped audiobook or music lyrics inside. Haven't tested it though, and I think there's no player that supports such scheme.
See the FAQ for more info.
So, what about MKS?
I couldn't find documentation about it, or even sample files. Maybe you can help.