The 64th Cannes Film Festival has opened with a gala screening of Midnight in Paris, a romantic comedy from US director Woody Allen.第64届戛纳电影节开幕

Owen Wilson, Rachel McAdams and Marion Cotillard appear in the film, alongside France's first lady Carla Bruni.

Ms Bruni announced on Tuesday she would not be attending the festival because of "personal reasons".

British hopes this year rest on We Need to Speak about Kevin, one of 20 films up for the prestigious¹ Palme d'Or（金棕榈奖）.

Directed by Scotland's Lynne Ramsay, the adaptation of Lionel Shriver's novel is the only British film in contention² for the festival's main award.

Tilda Swinton and John C Reilly co-star in the film, which details the events leading up to a high school massacre³.

Actors Jude Law and Uma Thurman are among the members of this year's international jury, chaired by fellow thespian⁴ Robert De Niro.

Johnny Depp, Angelina Jolie and Jodie Foster are some of the Hollywood stars expected at this year's festival, which runs until 22 May.

One of the key talking points is The Tree of Life, the long-anticipated feature from US film-maker Terrence Malick.

Brad Pitt and Sean Penn star in the film, a family saga⁵ set in the American Midwest during the 1950s.

Spain's Pedro Almodovar, Denmark's Lars von Trier and the Dardenne brothers of Belgium are among former Palme d'Or recipients⁶ who will be unveiling their latest work during the event.

Outside the main competition, the festival will also host gala screenings of two Hollywood sequels - Kung Fu Panda 2 and Pirates of the Caribbean: On Stranger Tides.

Hundreds of titles will be screened to distributors, potential buyers and members of the media during the festival.

One film that has already had tongues wagging is Unlawful Killing⁷, a documentary about the 1997 death of Diana, Princess of Wales.

Directed by Keith Allen, the film is understood to feature a paparazzi photograph of the princess in the aftermath of the Paris car crash that killed her and two others.

The British actor - father of pop star Lily - claims the film is "not about a conspiracy⁸ before the crash, but about a provable cover-up after the crash".