Patent ID: 7298913

Claim:
A method for encoding a video picture using reference pictures, comprising: assigning a video picture to one of a plurality of prediction groups of hierarchical layers including at least a first hierarchical layer and a second hierarchical layer higher than the first hierarchical layer; encoding the video picture assigned to a prediction group of the first hierarchical layer according to a motion compensated prediction interframe encoding mode, using a reference picture belonging to the prediction group of the first hierarchical layer; encoding the video picture assigned to a prediction group of the second hierarchical layer according to the motion compensated prediction interframe encoding mode, using a reference picture belonging to either of the prediction group of the first hierarchical layer and the prediction group of the second hierarchical layer; encoding first identification information indicating the hierarchical layer of the group to which the video picture belongs and second identification information indicating a prediction mode of the motion compensated prediction interframe encoding mode to generate side information; outputting the side information together with the video picture encoded according to the motion compensated prediction interframe encoding mode; setting a sum of the reference pictures assigned to the prediction groups to a constant value; and encoding reference picture number information indicating the number of reference pictures assigned to each of the prediction groups and including the coded reference picture number information in the side information.