Video coding and decoding apparatus with motion compensation

摘要

A coding/decoding apparatus performs predictive coding/decoding with motion compensation. A plurality of motion vectors are unified corresponding to motion of portions of a picture to obtain a motion vector group arranged in two-dimensional block. Motion vectors in the group are converted into one-dimension to obtain another motion vector group arranged in one-dimension. A motion vector value in the other group is predicted from another motion vector in the same group to obtain a motion vector predictive residue. The motion vector predictive residue is then coded with variable-length codes including zero run length codes to obtain a bitstream per motion vector group. The bitstream of motion vector groups composed of variable-length codes including zero run length codes are decoded to obtain a fixed-length motion vector predictive residue. A predictive value obtained from another motion vector is added to the fixed-length motion vector predictive residue to obtain motion vectors as a one-dimensionally arranged motion vector group. The one-dimensionally arranged motion vector group is converted into two-dimension to obtain a two-dimensionally arranged motion vector group in which motion vectors are unified in vertical and horizontal directions. Each vector in the two-dimensionally arranged motion vector group is output in accordance with motion compensation processing to each portion of a picture. <IMAGE>