Doesn't work over USB, only wifi for cameras that have it (no video). Best at the moment is dslrcontroller for iOS as it's almost as fast as hdmi but it's for jailbroken devices only and it's purely a viewer, no controls yet. And it doesn't work with raw. Afaik raw disables this h.264 output stream as it doesn't work with the canon eos utility either. So someone would have to make a modded version of the mlv module (likely sacrificing data rate)