Conventionally, as a portable equipment, there is a recording/reproducing apparatus such as a digital video cassette recorder. Such a recording/reproducing apparatus can record and reproduce images and voices at any place by being brought because its characteristic is portable, so that it is at present utilized widely. Besides, some of such recording/reproducing apparatuses record inputted video and audio signals in the state of digital signals on a recording medium such as a magnetic tape, and at this time, for the error correction of video and audio signals to be reproduced, add error correction codes generated by an error correction coding processing in order to record. As such an error correction coding processing, coding with multiplication codes is often utilized.