Various embodiments for transmitting a bitstream via a network are provided. The bitstream includes an index identifying a motion vector from a candidate list. The candidate list is generated by: adding, when a motion vector used for coding a first block spatially adjacent to the current block is useable for coding the current block, one or more first candidates to the candidate list; adding a second candidate to the candidate list, with the second candidate being derived based on a motion vector used for coding a second block within a first collocated picture; and adding a third candidate to the candidate list until a number of the plurality of candidates in the candidate list reaches a maximum number, with the third candidate being derived based on a motion vector used for coding a third block within a second collocated picture.