DECODING METHOD, DECODING APPARATUS, AND ENCODING METHOD

The decoding method is a decoding method for decoding a bitstream, in which a difference between a reference index and a prediction value of a motion vector is used for each block obtained by dividing each frame of a moving picture in which a plurality of frames are consecutive, in which a plurality of groups having a predetermined number of blocks are defined in each frame and a limitation is applied for each group to a range of reference index and differences of blocks other than the first block in the group, and the decoding method includes a step for determining whether the block to be decoded is the first block of the group, a step for decoding using the reference index and difference if the block is not the first block, and a step for decoding using the limited reference index and differences if the block is not the first block.