Abstract: More than two surround sound channels are provided within the format of a digital soundtrack system designed to provide only two surround sound channels by matrix encoding from three to five additional surround sound channels into two “discrete” surround sound channels. The digital audio stream of the digital soundtrack system designed to provide only two surround sound channels remains unaltered, thus providing compatibility with existing playback equipment. The format of the media carrying the digital soundtracks also is unaltered. The “discreteness” of the digital soundtrack system is not audibly diminished by employing matrix technology to surround sound channels, particularly if active matrix decoding is employed.

Abstract: A photosensitive medium, such as motion picture film, having digital data in multiple formats and analog audio signals photographically recorded thereon, and a system for photographically recording digital data (preferably including digital audio bits) in multiple formats and optionally also analog audio signals on a medium. Preferably, two digital soundtracks are recorded on the film, each in an array of bit areas arranged in row and column order, with the bit areas of one soundtrack between consecutive pairs of sprocket holes along one edge of the film, and the bit areas of the other soundtrack along the film edges outside the sprocket holes. Preferred embodiments of the invention include a camera assembly through which a motion picture film translates in real time.