Patent ID: 7801219

Claim:
A coding apparatus that codes a picture, said coding apparatus comprising: a coding unit operable to: code a co-located block which is a block included in a picture that is different from a current picture to be coded and located identically to a current block to be coded, using a motion vector of the co-located block and a reference picture corresponding to the motion vector of the co-located block, generate two motion vectors for the current block based on the motion vector of the co-located block which is a block included within a previously coded picture and co-located with the current block, and code the current block by performing motion compensation on the current block in direct mode using the generated two motion vectors for the current block and two reference pictures which respectively correspond to the generated two motion vectors for the current block, wherein in the case where the co-located block in the previously coded picture has been coded using only one motion vector, which is a backward motion vector, and a backward reference picture which corresponds to the only one motion vector, the backward reference picture being a reference picture located after the previously coded picture in display order, the backward motion vector being a motion vector that refers to a picture located after the previously coded picture in display order, and where both the current picture to be coded and the previously coded picture are B-pictures, and the only motion vector used for coding the co-located block which is included within the previously coded picture that is the B-picture is the backward motion vector, wherein said coding unit is operable to generate two motion vectors to be used for coding the current block by scaling, using a difference between information indicating display order of pictures, the only one motion vector used for coding the co-located block, and one of the two motion vectors refers to the previously coded picture that is the B-picture.