a method is disclosed of decoding audio data , encoded in multiple dif blocks in a digital video data stream , and outputting said audio data as a pcm frame , including the following steps : fetching a single digital interface frame block from the dv data stream ; de - shuffling a first byte in the single dif block to determine its index in the pcm frame ; repeating step until the last byte in the single dif block is processed ; writing the de - shuffled data into the pcm frame for output if the present dif block is the last in the present dv frame ; repeat steps to . also disclosed is apparatus arranged to perform the method , and de - shuffling equations to perform the de - shuffling of the data .