Abstract: A photosensitive medium, such as motion picture film, having digital audio signals photographically recorded thereon. If the medium has multiple, spatially separated digital and analog audio soundtracks, a photosensitive detector array is employed for each of the digital audio soundtrack areas, and a separate analog soundtrack read head is employed. Preferably, digital error code is recorded in a digital soundtrack area of the medium (with digital audio bits), and error detection and correction are performed on the recorded digital audio bits read from the medium. Preferably, the apparatus includes switching circuitry for substituting a corresponding analog audio signal for one or more corrupted digital soundtrack channels, when such digital soundtrack channels have an error rate which exceeds a selected threshold.

Abstract: A method and apparatus for photographically recording digital audio signals, and a medium having digital audio signals photographically recorded thereon. In a preferred embodiment, a motion picture film recorded in accordance with the invention has multiple digital audio soundtracks and an analog audio soundtrack photographically recorded thereon. Two or more channels of digital audio information can be recorded in each digital soundtrack, along with additional digital information for clocking, tracking, and error detection and correction. Each digital soundtrack is recorded in an array of bit areas arranged in row and column order. In a class of preferred embodiments, each row of digital audio bits is recorded simultaneously by exposing the film to radiation that has been modulated by a linear shutter array. The radiation transmitted by each shutter array is projected onto a row of spots. Each spot covers the full width of one of the bit areas in a row, but only part of the length of the bit area.

Abstract: A method and apparatus for reading digital audio signals photographically recorded on a medium (such as motion picture film). If the medium has multiple, spatially separated digital and analog audio soundtracks, a photosensitive detector array is employed for each of the digital audio soundtrack areas, and a separate analog soundtrack read head is employed. Preferably, digital error code is recorded in a digital soundtrack area of the medium (with digital audio bits), and error detection and correction are performed on the recorded digital audio bits read from the medium. Preferably, the apparatus includes switching circuitry for substituting a corresponding analog audio signal for one or more corrupted digital soundtrack channels, when such digital soundtrack channels have an error rate which exceeds a selected threshold.