‘The Departed’ leaves Leonardo in awe

His career ambitions were pretty much fulfilled, says Leonardo DiCaprio, when Martin Scorsese called him to talk about playing Howard Hughes in “The Aviator.”

“After we finished ‘Gangs of New York,’ I thought, ‘OK, I’ve worked with the best there is and I came out of it OK,’ ” he says.

So when Scorsese called him about doing his next film, “I felt – I don’t know, validated isn’t really the word maybe – but good, you know. It was like we had something together.

“But was there something more I wanted to do? Yeah. … I would have killed to make a great gangster movie with Martin Scorsese.”

No blood sacrifice proved necessary. According to DiCaprio, he and Scorsese each received the script for “The Departed,” which opened Friday, and both were knocked out.

“It was classic Scorsese stuff, cops and criminals and the thin line that divides them, but it was also very different than any of the gangster movies he had made before,” says DiCaprio, 31.

“The Departed” is a remake of a classic film, but one few people have seen: “Infernal Affairs,” a hit in Hong Kong in 2002.

In the story, two police cadets from the same class take very different routes to success: One gets kicked out of the academy and becomes right-hand man in a gang led by a ruthless killer. The other rises to the top of the police force.

But the gang member is an informant for the cops, and the cop is in the employ of the gangster as a mole. Eventually, both sides realizes there’s a rat in their midst, and the race is on to find him.

Scorsese set the story in South Boston, where gang boss Frank Costello (Jack Nicholson) has groomed a local kid since childhood to become a state policeman. Colin Sullivan (Matt Damon) eventually rises to the top of the Special Investigation Unit.

Meanwhile, Billy Costigan (DiCaprio) is secretly recruited by the police to insinuate himself into Costello’s gang.

Damon claims that he and DiCaprio flipped a coin to see who would play which character. DiCaprio won’t confirm that, but concedes Damon “would have been great as Billy.”

“One thing that really helped was having these Boston guys, Matt and Mark (Wahlberg), around,” he says. “They both really understood that culture and helped keep it authentic.

“I spent a lot of time in Boston before we started shooting, getting to know people, knocking around, and it’s really a place unto itself. Not like any other city I’ve spent time in.”

The same could be said for Nicholson. DiCaprio says that when he did his first scenes with the veteran actor, his focus was on “maintaining a similar level of intensity.

“I mean, Jack is Jack, the Jack. He doesn’t go out there much, but when he does, he brings it all. I had to be prepared, you know, because I knew what would be coming at me. No, I wasn’t scared. Let’s say I had to stay on my toes.”

The birthday bunch

Actor Paul Hogan (“Crocodile Dundee”) is 67. Actor-comedian Chevy Chase is 63. Actress Sigourney Weaver is 57. Actor Matt Damon is 36. Actor Nick Cannon (“Drumline”) is 26. Actor Angus T. Jones (“Two and a Half Men”) is 13.