Chinese filmmakers still face restrictions despite big strides towards artistic freedom since the Cultural Revolution, director Wang Xiaoshuai said Wednesday.
Chinese society had made progress, Wang said, at a showing in San Sebastian of his latest film "11 Flowers", set during the 1966-76 movement to transform China into a militantly Communist society.
"When it comes to the topic of art, of cinema, there are still things that they do not let us do," he told reporters at the film festival, without specifying which areas were bannned.
"Now we see people with much more freedom than during the Cultural Revolution. In Chinese society, unless you declare war on the government, nothing will happen to you."
China has a vast censorship apparatus, with films and television programmes particularly tightly controlled.
Wang's first movie "The Days", about a struggling married couple, was banned in China and his second "Frozen", about an artist who decides his final act will be to commit suicide through hypothermia, was released under a pseudonym.
He said "11 Flowers", one of 16 movies in the official selection for the Golden Shell prize at the September 16-24 San Sebastian film festival, was based on his experiences as a youth.
It tells the tale of an 11-year-old who is confronted by a wounded runaway murderer who asks for his help.
"During the Cultural Revolution you had to choose which side you were on to survive that moment," said Wang.
Wang's movies, known for their sensitive portrayal of the young, have proven popular with audiences at international film festivals.
His 2001 picture "Beijing Bicycle", which contains a critical view of contemporary Chinese life, won the grand jury prize at the Berlin film festival.
Four years later he won the jury prize at the Cannes Film Festival for "Shanghai Dreams", about a family that moves from Shanghai in the 1960s to work in the undeveloped Guizhou Province.
The San Sebastian film festival, the Spanish-speaking world's oldest and most prestigious, wraps up Saturday with a world premiere of "Intouchables", an out-of-competition French comedy about a friendship beween a millionaire tetraplegic and his ex-convict carer.