These cops are vicious assholes. The cop who does most of the hitting, and who keeps saying "stop resisting" over and over again is putting on a bullsh!t show for the camera's audio track (he might as well have been saying "stop hitting yourself, stop hitting yourself).
You can tell by the position of the drunk guy's feet (white tennis shoes which you can see near floor level) during the "procedure" that the dude is NOT moving around very much.
It's also obvious that all four officers know exactly where the camera is, and that they make sure their bodies block the cameras view of what is going on.
Whatever else happens, these men should NOT be allowed to be police officers anywhere in this country.