A executable program that is executed by a processor to implement decoding method: receiving (S 122) an encoded bitstream of a two-dimensional panorama picture, and determining an applicable spatial layout format of the two-dimensional panorama picture; parsing the encoded bitstream of the two-dimensional panorama picture, to determine whether a spatial position relationship between sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is a default spatial position relationship; and decoding the encoded bitstream of the two-dimensional panorama picture based on the applicable spatial layout format and the default spatial position relationship if the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship; wherein if the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship, the encoded bitstream does not include further information relative to said spatial position relationship between sub-pictures besides said indication information used to indicate that the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format use the default spatial position relationship; and wherein the parsing the encoded bitstream of the two-dimensional panorama picture, to determine whether a spatial position relationship between sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is a default spatial position relationship comprises: parsing the encoded bitstream of the two-dimensional panorama picture, to obtain a default spatial position relationship indication identifier, and when the default spatial position relationship indication identifier is a first value, determining that the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship. receiving (S 122) an encoded bitstream of a two-dimensional panorama picture, and determining an applicable spatial layout format of the two-dimensional panorama picture; parsing the encoded bitstream of the two-dimensional panorama picture, to determine whether a spatial position relationship between sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is a default spatial position relationship; and decoding the encoded bitstream of the two-dimensional panorama picture based on the applicable spatial layout format and the default spatial position relationship if the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship; wherein if the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship, the encoded bitstream does not include further information relative to said spatial position relationship between sub-pictures besides said indication information used to indicate that the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format use the default spatial position relationship; and wherein the parsing the encoded bitstream of the two-dimensional panorama picture, to determine whether a spatial position relationship between sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is a default spatial position relationship comprises: parsing the encoded bitstream of the two-dimensional panorama picture, to obtain a default spatial position relationship indication identifier, and when the default spatial position relationship indication identifier is a first value, determining that the spatial position relationship between the sub-pictures in the two-dimensional panorama picture in the applicable spatial layout format is the default spatial position relationship.