MKV is not supported simply because it's not a video format. The Matroska Multimedia Container is a free and open container format, a file format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. However, you can try to rename a videoname.mkv file to videoname.mpg and if that mkv-container has a valid video file, you will be able to use it as a Descapes dream. A more ideal solution would be to convert your mkv-files to mpg.
