In a competition that is swathed in sound, with many of the films punctuated by strident music, "Sleeping Beauty" seems to be accompanied by a slight, ominous hum.

"I worked closely with my wonderful sound man, Sam Petty," Ms. Leigh said. "There's a lot of sound design, but there isn't a lot of Ben Frost's fine score, perhaps only 10 minutes in all, yet it magically enhances the Sleeping Beauty Chamber. And I think the shooting style with longer takes allows people to use their imagination: When you get into that chamber, you're quite close to being complicit."

Ms. Leigh, who lives in Sydney with her husband, a lawyer and playwright, said she loved the festival for the international focus it brought to smaller films. "Without Cannes, many films wouldn't have made it to Australia, such as last year's Palme d'Or, 'Uncle Boonmee Who Can Recall His Past Lives.' So I hope that our film, too, will have a bigger life, beyond the festival," she said.

The 35-year-old filmmaker Maïwenn first came to Cannes after playing the child version of Isabelle Adjani's character in "L'été meurtrier" (One Deadly Summer) in 1983. And 15 years ago, when she was married to Luc Besson, she came with his film "The Fifth Element," which she acted in.

"Polisse," her third film as a director, was presented to the public on Friday night. She had slept only two hours and was being hugged and waved at from all sides as we talked in her hotel's breakfast room the next day.

The French rapper Joeystarr, her partner off-screen, and who in fact plays a police officer in "Polisse," also ducked by for a quick hug.

Cellphones on the tables were flashing, alight with the morning news. She had not yet read the reviews and was happy to hear that they were mostly good.

"Polisse" — a child's spelling for Police — is a tough inside look at a group of men and women who work together on child abuse cases. They listen, they witness, they ply confessions from pedophile fathers and grandfathers; they also work with the children, and don't always treat them with kid gloves. They have moments of despair — and wild giggling.

To prepare for the film, Maïwenn spent months with a Paris juvenile protection unit. Two advisers were on the set as she shot "Polisse," which stars Karin Viard, Marina Foïs, Sandrine Kimberlain, Nicolas Duvauchelle, Frédéric Pierrot and Arnaud Henriet.

The film's co-author, the screenwriter Emmanuelle Bercot, also has a part in the movie as a policewoman, and Maïwenn herself plays a photographer who drops her shy girl posture and glasses to join the highly volatile brigade. She takes a lover, Fred, a hyperactive and hypersensitive officer played by Joeystarr.

My movies have always been about childhood," she said. "So even when I want to make a movie on the police, I see that I am making another movie about childhood. And, many characters were inspired by those I met when I visited the division. The movie presented itself as an ensemble piece."

The characters depicted in the film have complicated home lives; most are separated and have scant time for their own children; many drink. "I felt they were carrying a weight, perhaps a sense of shame," she said.

Though slight and soft-spoken, Maïwenn is a forceful woman who chooses her words with care. "I like filmmaking that is discreet," she said of her stylistic approach. "I don't care about reverse shots and special camera angles, or complex lighting."

At the conference, following the press screening, Maïwenn had referred to her own participation in the film as a possible casting error. "I had to be very careful about the nature of my character," she said during the interview. "I think I wanted to play a part because I was affected by the police I met on their jobs, the shock of these people — tough-talking and cursing.

"My part is this shy studious girl. It's very hard to be a woman in a man's world and hard on the women who are part of the gang. I felt they had the same kind of handicap that I have: They had something to prove."

Unlike her screen character, Maïwenn, who was raised in Paris, stopped school at the age of 12, along with her younger sister, the actress Isild Le Besco. "I was just too bad at it; so was my sister. We did correspondence courses," she said.

Both women have a childlike, exotic beauty. Their father is Breton from Vietnamese parentage. Their mother is Algerian, and long dreamed of her daughters becoming actresses.

"When I started making movies I got tough," Maïwenn said. "You have to be an orchestra leader and you can't be fragile." But, she added, "I'm fragile too, and I like being protected by my man, so it's hard."

The director remembers coming to Cannes 15 years ago for the opening of "The Fifth Element."

"I was married to Luc, but he had left me," she said.

"I put on a dress I had made, a dress with angel's wings and a crown, and got ready to accompany the team on the red carpet. But nobody came to pick me up at the hotel. So, when it hit me, I ran barefoot to the Palais, cut my foot on the way, and got to the stairs, my foot bleeding. But the team was already inside the theater, and they had pulled the red carpet up. It was a terrible humiliation."

This year, Maïwenn, wrapped in a midnight blue gown, presenting "Polisse" in the Palais, won a 20-minute ovation. This, too, is the kind of thing that can happen at Cannes.

Joan DUPONT
www.nytimes.com