MOTION PICTURE DIGITAL SOUND SYSTEM AND METHOD WITH PRIMARY SOUND STORAGE EDIT CAPABILITY

摘要

A digital sound system for motion picture films employs a digitaltime code (20) on the film (4) to trigger the transfer of sound datafrom a digital audio store (40) to a FIFO memory (42). The digital audiodata is read out from the FIFO memory and played back in thetheater at a constant rate, with any jumps in the digital time code handledby making a corresponding jump within the digital audio storebut not in the FIFO memory. Readout from the FIFO memory andclocking of the digital-to-analog converters (DACs) (DAC 1-4) usedfor theater playback is synchronized to the AC mains (54) that powersthe theater projector, and thus allows for an uninterrupted audioplayback even if time code entries on the film are obliterated. The FIFOmemory need only have enough capacity to accomodate the maximumaudio store access time, and can be quite small.