MKVs are capable of having multiple video streams inside of it. Some BluRays make use of multiple video streams, like animated films where some content like signs is translated to different languages. Or some films do have several video streams with additional content like a "before-CGI" version of the movie. Or you can choose of 2D video vs. 3D video.   Kodi will support this in "Krypton" (version 17). http://forum.kodi.tv/showthread.php?tid=216672 So this works, when using "Direct Play".