1. An apparatus for decoding a current block, the apparatus comprising: a decoding unit configured to extract a first identification information from a bitstream, wherein the first identification information indicates whether a motion vector of the current block is set as one of a plurality of motion vector candidates, and reconstruct a quantized frequency residual block of the current block from the bitstream; a dequantization and inverse transform unit configured to dequantize and inversely transform the quantized frequency residual block to reconstruct a residual block of the current block; an inter prediction unit configured to, in response to the first identification information indicating that the motion vector of the current block is set as one of the plurality of motion vector candidates, generate the plurality of motion vector candidates of the current block from neighboring blocks of the current blocks, select a motion vector candidate from the plurality of motion vector candidates based on a second identification information, the second identification information being decoded from the bitstream, reconstruct the motion vector of the current block as the selected motion vector candidate, and generate a predicted block of the current block by using the reconstructed motion vector of the current block; and an addition unit configured to add the predicted block to the residual block so as to reconstruct the current block.