The carnage happened live, not on TV — and witnesses who saw a Brooklyn dad firing his assault rifle from his window onto a crowd of rowdy teens said the violence was “better than HBO,” a defense lawyer said in openings of the attempted-murder trial yesterday.

Prosecutors say Thomas Dunikowski, 32, aimed directly at the teens with his AR-15 and kept shooting until he hit one in the neck, while the defense maintains he fired only in self-defense.

“He was aiming directly at them,” Assistant DA John Sharples said in Brooklyn Supreme Court.

Neighbors who filmed the fighting that led to the shooting can be heard saying, “Grab a chair. This is better than HBO,” and “It’s Brooklyn. If this was Long Island, there would be six cop cars here already,” defense attorney Jay Schwitzman told jurors. Schwitzman said the comments bolster his case that the teens were acting aggressively and police presence was scarce.