Bar Fight Video Shows Violent Chaos

TMZ Sports has obtained video of the wild bar fight that led to the arrest of ex-NFL star Pacman Jones ... and you can hear people begging for the violence to stop.

The barstools were flying. People went crashing to the ground. And, it's a miracle more people weren't seriously hurt.

Here's the backstory, per the witness who shot this video ...The drama began after 37-year-old Pacman and someone from his crew left the Clutch OTR bar in Cincinnati around 1 AM on Monday morning -- and the security staff wouldn't let them back inside.

"Pacman pushed his way back in and it started getting aggressive," the witness tells us.

We're told Pacman got into a heated verbal confrontation with the DJ -- and…