Depends. If you have media settings set to 'fully transcode', thereby having the pogoplug (albeit VERY slowly) convert the files for you, then either of those video formats will be streamable. Otherwise, you would need to convert .mpg, .avi, .mov etc to mp4 or m4v format for video streaming to mobile devices and other pc's. I usually use Handbrake to convert which seems to work for me.