Patent ID: 8848798

Claim:
An information processing apparatus comprising: a processor and a memory storing an encoder configured to encode a moving image signal, wherein: the encoder, when executed by the processor, is configured to: generate a prediction signal, using one of a plurality of types of inter-prediction modes having different block sizes as a processing unit, for each of macroblocks obtained by dividing a picture to be encoded, the one of the plurality of types of inter-prediction modes being an optimum type of inter-prediction mode; perform orthogonal transformation for a prediction residual signal, by using one of a plurality of types of DCTs having different block sizes as processing unit, wherein the prediction residual signal is obtained by subtracting the prediction signal from a picture signal of the macro block, and wherein the one of the plurality of types of DCTs is an optimum DCT; and determine a combination of the optimum inter-prediction mode used by an inter-prediction unit and the optimum DCT used by the transformation unit for each of the macroblocks, the determining of the combination comprises: calculating first costs associated with each of one or more specified types of inter-prediction modes in combination with each of the plurality of types of DCTs, a number of the one or more specified types of inter-prediction modes being smaller than a total number of the plurality of types of inter-prediction modes; selecting a predetermined number of types of DCTs from the plurality of types of DCTs, based on the calculated first costs, the predetermined number being smaller than a total number of the plurality of types of DCTs; calculating second costs associated with each of the plurality of types of inter-prediction modes in combination with each of the selected predetermined number of types of DCTs; and selecting one of the plurality of types of inter-prediction modes as the optimum inter-prediction mode and one of the selected predetermined number of types of DCTs as the optimum DCT based on the calculated second costs.