Predictive encoding and data decoding control

Abstract

A shortest cut duration is a minimum required period between an edit point set on a stream of pictures such as an MPEG stream and the next edit point set on the stream. Restrictions are made on the shortest cut duration lenient in a process to seamlessly reproduce a result of editing the stream in order to enhance the freedom of editing in carrying out a process of editing the stream. A controller detects each edit point set on the stream and, for the edit point, the controller identifies fewest possible pictures, which are not to be displayed but must be decoded first before decoding a picture to be displayed after the edit point. Then, the controller finds a start point representing a timing to start a process of decoding the one or fewest possible pictures. Subsequently, the controller controls processes carried out by decoders to decode the stream in picture units on the basis of the start point, and controls a switcher to select one of outputs of the decoders on the basis of the edit point.