An apparatus decodes encoded moving image data in which a picture is divided and encoded, into two or more small areas that include at least a block and do not overlap with each other. The apparatus includes: a unit configured to decide first and second parameters being decoding parameters of another block for which decoding has already been performed in the same picture and referred to in an entropy decoding process and an extension process of each block, using position information of each small area and reference relation information to another small area; a decoder configured to perform the decoding process, in an order of the decoding process and the extension process, by referring only to the first parameter; and an extender configured to perform the extension process in the order by referring only to the second parameter in compression information of each block obtained by the decoding process.