Gallenberger is known in China for John Rabe, a 2009 biopic based on the Nanjing Massacre. [Photo provided to China Daily]

Gallenberger says the film has made a splash in Germany and Chile, focusing public attention on a relatively ignored chapter in history.

"German filmmakers are doctors who operate precisely on the wound of history until darkness and truth are starkly exposed before us," he says.

Born in Munich, Gallenberger began his film career as a child actor. But his interest transferred to directing and he proved his talent behind the camera.

In 2001, Gallenberger's short drama Quiero ser (I Want to Be)won an Oscar for best short subject.