METHOD FOR CALCULATING DIRECT MODE MOTION VECTOR OF B PICTURE

摘要

PURPOSE: A method for calculating a direct mode motion vector of a B picture is provided to improve the coding efficiency for a B picture by increasing the possibility of selecting a direct mode as a predictive mode of a macro block. CONSTITUTION: In the case that a list 1 reference picture for direct mode of a B(Bi-predictive) picture is placed before or after the B picture in the matter of time, one motion vector is decided as a motion vector for inducing a motion vector of a direct mode regardless of modes of motion vectors of a co-located block in the list 1 reference picture for direct mode. The decided motion vector is scaled to induce a list 0 motion vector(MV_F) and a list 1 motion vector(MV_B) for calculating a direct mode motion vector of the B picture.