I think, that the only way to do this is, to create camera for each player, but I'm not sure. There will be a lot of triggers of course, but there's not so much work - you just copy,paste triggers and change players at triggers. That's not 100% so...
Another idea! I gues that you are creating multiplayer scenario, aren't you? Try to download some multiplayer scenarios, and you may found a map with cinematic for all players. Open map in editor and see how it's created.