That's a quandry. See, JK1 used smacker video files (viewable in smacker) but MotS used SCN format I think. I don't know, but it may have been a proprietary format. I'm not sure if anyone ever created a viewer for it outside the game, honestly... sorry I couldn't be more helpful there.
Edit: I do remember though that all the cutscenes from MotS were actually stored in a zip file on the MotS CD. See, they used "game engine" scripting to create the cutscenes, and then "filmed" them into the SCN format. So if you unzip the Cutscenes.zip file you'll find a goo you can load as a level and view all the action. The only thing missing is the voice files. You can find the voices and music in the game's goo files as well, in the form of wav files and CD audio. So with some editing work, you could piece together the cutscenes and record them in a higher quality format if you like (many fans complained about the relatively low quality of the SCN videos). I imagine the low quality was done to save space to fit the whole thing on 1 cd. Similarly they compressed the audio so it was "low res" only (rather than JK1, where they had two cd's, so they had room for "high res" sound and the nice cutscenes).