Motion vector calculation method

摘要

When a block (MB22) of which motion vector is referred to in the direct mode contains a plurality of motion vectors, 2 motion vectors MV23 and MV24, which are used for inter picture prediction of a current picture (P23) to be coded, are determined by scaling a value obtained from averaging the plurality of motion vectors or selecting one of the plurality of the motion vectors.

主权项

1. A picture coding and decoding system which includes a picture coding apparatus that codes a current block included in a current picture to be coded and a picture decoding apparatus that decodes coded data of a current block included in a current picture to be decoded,
wherein the picture coding apparatus includes: a referring unit:
operable to refer to a first list in which smaller indices are assigned to pictures preceding a current picture in display order than indices assigned to pictures following the current picture, the first list being a list of index associating blocks included in the current picture with each picture that is referred to by the blocks, andoperable to refer to a second list in which smaller indices are assigned to pictures following the current picture in display order than indices assigned to pictures preceding the current picture, the second list being a list of index associating blocks included in the current picture with each picture that is referred to by the blocks; a selecting unit:
operable to select, from the first list, as a first reference picture, a picture with the smallest index out of a plurality of pictures that are referred to by a plurality of neighboring blocks, the plurality of neighboring blocks being located at the neighborhood of a current block in the current picture to be coded, andoperable to select, from the second list, as a second reference picture, a picture with the smallest index out of the plurality of pictures; and a coding unit operable to predictive-code the current block by referring to the first reference picture and the second reference picture, wherein the picture decoding apparatus includes: a referring unit:
operable to refer to a first list in which smaller indices are assigned to pictures preceding a current picture in display order than indices assigned to pictures following the current picture, the first list being a list of index associating blocks included in the current picture with each picture that is referred to by the blocks, andoperable to refer to a second list in which smaller indices are assigned to pictures following the current picture in display order than indices assigned to pictures preceding the current picture, the second list being a list of index associating blocks included in the current picture with each picture that is referred to by the blocks; a selecting unit:
operable to select, from the first list, as a first reference picture, a picture with the smallest index out of a plurality of pictures that are referred to by a plurality of neighboring blocks, the plurality of neighboring blocks being located at the neighborhood of a current block in the current picture to be decoded;operable to select, from the second list, as a second reference picture, a picture with the smallest index out of the plurality of pictures; and a decoding unit operable to decode the current block by referring to the first reference picture and the second reference picture.