1. A video encoder comprising: a motion estimation unit which generates a motion vector of a current block and a motion vector of each of neighboring partitions around the current block; a motion vector estimation unit which selects at least one of partitions, which are compared with the current block for obtaining a motion vector difference, among a plurality of candidate partitions around the current block and a candidate partition located in a position in a reference picture that spatially corresponds to the position of the current block, estimates the motion vector of the current block based on a motion vector of the selected at least one of partitions, generates the motion vector difference, and transmits information on the motion vector difference, and partition information, for reconstruction of the motion vector of the current block, indicating the selected at least one of partitions; and an entropy-coding unit which performs entropy-coding on the information on the motion vector difference, and the partition information, for reconstruction of the motion vector of the current block, indicating the selected at least one of partitions, wherein the plurality of candidate partitions around the current block are selected from the neighboring partitions around the current block.