A software carrier for storing thereon digital data representative of a motion picture, said digital data having a data structure comprising a lead-in section followed by a plurality of successive data blocks, said data blocks representing an image program and a plurality of audio tracks synchronized with said image program, said lead-in section containing data indicative of the language of any dialog represented in said audio tracks, and a code for each of said audio tracks identifying its use as either a switching master including music and effects and dialog language of predetermined length, a mixing master containing only music and effects of predetermined length, a shorter track containing audio segments to be switched with said switching master, or a shorter track containing audio segments to be mixed with said mixing master.