By Ian Youngs BBC News Online correspondent in Cannes

Caouette said editing his tapes was "extremely painful"

Tarnation, a powerful autobiographical documentary by director Jonathan Caouette, has been one of the surprise hits of the Cannes Film Festival - despite costing just $218 (£124) to make.

After Tarnation screened for the second time in Cannes, Caouette - its director, editor and main character - stood up.

A spotlight was thrown on him and he fought back tears as the cinema crowd gave him a standing ovation.

The audience had just watched his life story.

A Texan child whose mother was in shock therapy, Caouette, 31, was abused in foster care and saw his mother's condition worsen as a result of her "treatment".

He began filming himself and his family aged 11, and created movie fantasies as an escape.

The whole time I was editing the film, there were tears coming and there was this pulling coming from my stomach Jonathan Caouette

For Tarnation, he has spliced his home movie footage together to create a moving and uncomfortable self-portrait.

And using a home computer with basic editing software, Caouette did it all for a fraction of the price of a Hollywood blockbuster like Troy.

"What happened with the standing ovation was the most amazing response I've got from this film in my life," he told BBC News Online.

"I felt like Diana Ross in the last scene of Mahogany or Lady Sings the Blues. It was so surreal and such an out-of-body experience.

The film documents his mother's mental health problems

"It felt like a flash was going to go off and everything was going to freeze frame and credits were going to roll and I was going to wake up from some elongated dream that I've been having."

Caouette said he had been "inadvertently making this film for 20 years", and telling his story was a cathartic process he needed to go through.

But reviewing and editing his tapes - from his early acting performances to footage of his deteriorating mother - was also "extremely painful", he said.

"The whole time I was editing the film, there were tears coming and there was this pulling coming from my stomach - it was unlike anything I'd ever experienced."

Last year's Cannes Palme d'Or-winning director Gus Van Sant and Hedwig and the Angry Inch film-maker John Cameron Mitchell liked it so much they came on board as executive producers.

The director said he has had offers to make other films

"John and Gus have both given their championships to the film and endorsed the film as executive producers," Caouette said.

The film's reputation has grown rapidly - the finished version was only finalised for the Sundance Film Festival in January, after which the director received hugs from strangers who had seen it.

It is now in the prestigious Un Certain Regard section at Cannes.

"What a way to introduce yourself to an industry that you've always fantasised about being in," Caouette said.

"I was really reluctant at the beginning to take it to this level - but now that I'm here, it's the most freeing thing I've ever experienced in my life."

Caouette in a scene from the film

As for the budget, which has attracted as much attention as the subject matter, Caouette said he had added up how much he spent on video tapes - plus a set of angel wings - over the years.

But the total spent will rise to about $400,000 (£230,000), he said, once rights for music and video clips he used to illustrate a mood or era have been paid for.

Although Tarnation is a unique and highly personal project, Caouette said he has had several offers at Cannes for future films, and would like to make a "parapsychological horror".

But he will not ditch Tarnation's style, and is inspired by Danish director Lars Von Trier, he said.

"I love the idea of making a narrative where it feels like the audience member is peeping in on something that they don't necessarily know if they should be peeping in on."