Cops are investigating Kanye West for allegedly punching an autograph seeker, and TMZ has obtained this video showing the man laid out on the street as Kanye rages at people who apparently work for him.

As we've reported, the alleged attack went down around 3 AM in DTLA, outside the SoHo Warehouse -- and Ye was absolutely livid. When the video starts he's screaming, "get away from me" at a woman who's desperately trying to calm him down. She also says, "I am your family," but he continued storming away in anger. We're told the woman is Ye's cousin.