Picture encoding apparatus, picture encoding method, picture decoding apparatus, picture decoding method and presentation medium

摘要

A picture encoding apparatus, a picture encoding method, a picture decoding method and a presentation medium capable of making efficient random accesses at a high speed. The picture encoding apparatus for encoding a picture and outputting an encoded bitstream obtained as a result of encoding said picture comprises a hierarchy forming means for converting a sequence of objects composing said picture into a hierarchy comprising two or more hierarchical layers, a first encoding means for encoding a first hierarchical layer of said sequence of objects output by said hierarchy forming means by dividing said first hierarchical layer into a plurality of groups, and a second encoding means for encoding a second hierarchical layer of said sequence of objects output by said hierarchy forming means by dividing said second hierarchical layer into a plurality of groups in such a way that an object at said second hierarchical layer to be displayed at a time coinciding with or immediately after a display time of an object first displayed in a group pertaining to said first hierarchical layer is first displayed in a group pertaining to said second hierarchical layer.