If you're asking me I'm not sure but it seems to be doing at least SOMEthing with my blu-ray rip (which is a lot more than I can say for the many methods I've used up til now) 3 mins to go then there's another (?) .mkv file on my desktop that I'm assuming I'll be able to put into BDSuptoSub as per Roidy's instructions (Is that right, Roidy?)