I have some dual audio avi video file with external subtitle and I decided to convert to mkv one so that I could tag the audio stream and the subtitle one, but in this case the television shows file unreadable after a couple of second while the files play fine if Mezzmo stream them as avi with external subtitle.
If I decide to pre-transcoding them however the file play fine, but I cannot choose the different audio tracks and I don't have the subtititle.