Motion picture digital sound system and method

Abstract

A digital time code is printed in an area of a motion picture film, between the normal analog optical sound track and the picture frames, that is exposed along with the sound track when a print is made. This area is partially redeveloped, and normally reserved to isolate the analog sound track from the picture frames. Digital audio for the motion picture is stored in a large capacity high integrity archival digital storage system. The time codes corresponding to known locations on the film are read as the film is played, and in an anticipatory pass the digital audio signals for these frames are transferred to a fast access data storage buffer which temporarily stores the data before it is converted to analog format for theater play. The time code is read with light that is absorbed by the film dyes produced when the film is developed. Temporary storage of the digital audio signal in the buffer memory accommodates breaks in the film, projector changeover and various time code validation schemes, and allows the digital data source in which the digital audio data is stored to be a relatively slow access high data reliability device such as a digital tape.