Oscars set to be a two-horse race

Hollywood is holding its breath ahead of the Oscars, with dark comedy Birdman and coming-of-age drama Boyhood neck-and-neck in the awards season home stretch.

Tinseltown's finest will be on the edge of their seats on Sunday night (Monday AEDT) at the Dolby Theatre, waiting to finally learn who will win a coveted golden statuette - and who will walk away empty-handed.

Julianne Moore, Patricia Arquette and Britain's Eddie Redmayne are among those widely tipped to take home acting prizes during the show, hosted by song-and-dance man Neil Patrick Harris.

But the race for the biggest prize of the night, the best picture Oscar, remains too close to call with only a couple of days to go.

Birdman, a fanciful yet dark tale of a washed-up superhero actor battling to revive his career on Broadway, has swept a string of prizes ahead of the Oscars including top prizes from the Screen Actors Guild and the Directors Guild of America.

But Richard Linklater's Boyhood - which was made over 12 years with the same actors ageing with their characters - scooped up the biggest awards at last month's Golden Globes, as well as Britain's BAFTAs.

Some have even suggested that Clint Eastwood's American Sniper could sneak up on the inside as a dark horse, boosted by the film's box office success as the highest-grossing war movie of all time.

When nominations were announced last month, Birdman shared the most nods with Wes Anderson's stylish crime caper The Grand Budapest Hotel, at nine each, followed by World War II thriller The Imitation Game with eight.

Boyhood followed with six.

While the best picture race is on a knife-edge, several of the other key categories are seen as much easier to predict.

Veteran star Moore is almost universally expected to win best actress for playing a linguistics professor suffering from early-onset Alzheimer's Disease in Still Alice.

Arquette is the favourite for best supporting actress as the single mother raising two kids in Boyhood, while J K Simmons is widely expected to win best supporting actor honours for jazz drama Whiplash.

The best actor race is still seen as up for grabs - a two-man contest between Redmayne - as astrophysicist Stephen Hawking in The Theory of Everything - and Birdman star Michael Keaton.

For best director, the frontrunners are Linklater and Mexico's Alejandro Gonzalez Inarritu, the creative force behind Birdman.

This has led to speculation that the best picture and best director prizes could be shared, as they were last year when Mexican Alfonso Cuaron won best director for Gravity, while the best picture Oscar went to 12 Years A Slave.

A star-studded cast of presenters will hand out the prizes at Sunday's show, including Ben Affleck, Scarlett Johansson, Australian Nicole Kidman, Eddie Murphy, Liam Neeson, Gwyneth Paltrow, Meryl Streep and Oprah Winfrey.

Harris will have the tough task of following last year's widely-praised mistress of ceremonies, Ellen DeGeneres.

One unwelcome guest could be rain - forecasts say there is a 60 per cent chance of what is a rare LA phenomenon.

Last year, a last-minute freak storm forced organisers to scramble to make sure it didn't rain on the party.

They will be hoping the clouds hold off for as long as possible.