One macroblock is constructed by 16.times.16 pixels (bytes). When the macroblocks are stored in a frame memory constructed by a DRAM or the like, addresses are sequentially allocated in an ascending order in a manner such that addresses 0000 to 0255 are allocated to the first macroblock and addresses 0256 to 0512 are allocated to the second macroblock and the macroblocks are stored. The macroblocks stored in this manner are read out in the ascending order of the addresses.