Moving picture coding device, moving picture coding method, and moving picture coding program

A moving picture coding method adapted to encode a coding block consisting of two prediction blocks, comprising:

• encoding an index into a bitstream, the index is specifying a merging motion information candidate used in a prediction block subject to encoding;
• generating a merging motion information candidate list including a plurality of merging motion information candidates for all the prediction blocks in the coding block using candidate blocks not neighboring the prediction block but neighboring the coding block, when a size of the coding block is smaller than a threshold size;
• and
• selecting one merging motion information candidate from the merging motion information candidate list and to decide the index.

A non-transitory computer-readable recording medium having embodied thereon a moving picture coding program adapted to encode a coding block consisting of two prediction blocks, the moving picture coding program causing a computer to execute:

• encoding an index into a bitstream, the index is specifying a merging motion information candidate used in a prediction block subject to encoding;
• generating a merging motion information candidate list including a plurality of merging motion information candidates for all the prediction blocks in the coding block using candidate blocks not neighboring the prediction block but neighboring the coding block, when a size of the coding block is smaller than a threshold size;
• and
• selecting one merging motion information candidate from the merging motion information candidate list and to decide the index.