A method and apparatus for, in a video encoding and decoding procedure, selecting a candidate motion vector of a current block from a motion vector candidate list of the current block, determining a motion vector of the current block by performing a motion search based on the candidate motion vector, performing motion compensation by using the determined motion vector of the current block, and applying local luminance compensation to the current block based on whether the local luminance compensation is to be applied to the current block, wherein a cost function used for performing the motion search is determined based on whether the local luminance compensation is to be applied to the current block.