When Johnny Depp climbed the Palais’ red-carpet steps Saturday for the bow of Disney’s “Pirates of the Caribbean: On Stranger Tides,” it gave the Cannes fest exactly what it needed: Hollywood hoopla.

The throng of film fans whooped and screamed, as they undoubtedly will today at the sight of Brad Pitt for “The Tree of Life” (which Fox Searchlight has in the U.S.). The majors’ specialty arms such as Searchlight, Focus Features and Sony Pictures Classics have long known the advantages of embracing Cannes.

But the majors themselves are sometimes more wary. With approximately 4,000 journalists here, Cannes can be an invaluable launchpad, but it’s also an expensive risk, and if your film flops, you fall on your face in front of the whole world.

Still, with 67% of studios’ box office coming from outside the U.S., their attitude has become increasingly opportunistic. Cannes has become an opportunity — either for an actual international press junket or a publicity blitz that serves as one.

Other studio pics with high profiles here include Paramount/DreamWorks’ “Kung Fu Panda 2” and “Puss in Boots,” Par’s “Transformers: Dark Side of the Moon” and “Super 8,” Disney-Pixar’s “Cars 2,” and Universal’s “Cowboys and Aliens.”

Hollywood’s highest-grossing studio, Warner Bros., is absent this year, though it’s used the fest in the past to launch such pics as “The Matrix Reloaded” in 2003, “Troy” in 2004 and “Ocean’s Thirteen” in 2007 — the latter two with Pitt.

“It’s a wonderful place to premiere a film and get a press campaign going,” said WB worldwide marketing prexy Sue Kroll.

That’s a fairly new attitude toward the venerable festival, which launched in 1946. For years, the studios kept Cannes at arm’s length. But in 2001, Fox brought “Moulin Rouge” here and helped prove the payoff could outweigh the risks.

The second key moment came with Sony’s 2006 “The Da Vinci Code.” In every studio’s worst nightmare, the withering reviews were posted online before the premiere and the filmmakers tried in vain to look upbeat at the Palais. Negative buzz pursued the pic throughout the fest.

But the film grossed more than $750 million worldwide — 71% of that outside the United States — and reminded the majors that a Cannes pratfall isn’t necessarily the kiss of death. “When you show a film here, it really becomes a global event,” noted Paramount Pictures Intl. prexy Andrew Cripps. “When you get Angelina Jolie, Dustin Hoffman and Jack Black here, you’re guaranteed coverage on ‘Kung Fu Panda 2.’ ”

That toon opens in the U.S., Asia and Russia on the last weekend in May as it tries to match the $630 million worldwide the original took three years ago.

“Pirates 4” begins its massive rollout this week, with the crew coming to Cannes after splashy preems at Disneyland and in Moscow. The Mouse House is eyeing the $1 billion in worldwide B.O. from the third iteration.

Cripps noted that the DreamWorks Animation pics, distribbed by Par, have become a tradition at Cannes.

“We really got it started with ‘Shrek,’ and we’ve done it with ‘Madagascar,’ ‘Bee Movie’ and ‘Shark Tale,’ when we had the cast on an inflatable shark,” he added. “There’s a strong component of the foreign box office of families going to our movies together, so drawing the attention of the global media is increasingly important.”

The giant boots emblazoned with the “Puss in Boots” logo at the end of the pier next to the Carlton Hotel made a statement. By Friday, the footwear had been replaced with a structure with the “Mission: Impossible — Ghost Protocol” logo.

Par took a more low-key route with J.J. Abrams’ “Super 8,” which opens in mid-June. It held several screenings for journalists of about 20 minutes of footage, similar to what was shown in March during CinemaCon in Las Vegas.

20th Century Fox’s premiere of “Tree of Life,” starring Pitt and Sean Penn, on Monday should also bring plenty of buzz.

Like the studios’ specialty wings, indies are working hard at Cannes to start positioning their films. Lionsgate Intl. held an open house May 10, as did Sierra/Affinity.

Harvey Weinstein hosted a Friday evening party at the Hotel Martinez for press and buyers to tout upcoming titles, including the just-acquired “Iron Lady,” “Wu Xia,” and “The Artist.”

And Red Granite, which began the week by coming on to produce Leonardo DiCaprio starrer “The Wolf of Wall Street,” held a flashy launch party Saturday night with Kanye West performing. DiCaprio showed up during the latter stages of the bash — incognito as usual in a baseball cap.