A method for hierarchically encoding a motion picture including a plurality of random access units, each random access unit including a plurality of pictures (10, B1, B2, B3, P4,...) which are continuous in decoding order, each random access unit being a unit of decoding that includes a group of pictures, said plurality of pictures (10, B1, B2, B3, P4,...) including I pictures, P pictures and B pictures, each picture belonging to one of a plurality of temporal layers (Tld 0, Tld 1, Tld2), said I and P pictures belonging the lowest layer of the plurality of temporal layers, each picture of a certain layer being encoded without referring to another picture which belongs to a layer higher than the certain layer, said plurality of pictures (10, B1, B2, B3, P4,...) comprising a plurality of lower layer pictures (10, B2, P4,...), each lower layer picture belonging to one of one or more layers (Tld0, Tld 1) lower than a highest layer (Tld 2) of the plurality of layers (Tld 0, Tld 1, Tld2), and a plurality of highest layer pictures (B1, B3,...) belonging to the highest layer (Tld 2) of the plurality of layers (Tld 0, Tld 1, Tld2), the method comprising the steps of: determining, for each picture of the plurality of pictures (10, B1, B2, B3, P4,...), a respective decoding time; encoding each of the plurality of pictures (10, B1, B2, B3, P4,...) in accordance with an encoding order according to the determined respective decoding times; and generating an encoded stream including the plurality of encoded pictures and the determined respective decoding times for the plurality of pictures (10, B1, B2, B3, P4,...), characterized in that the plurality of highest layer pictures (B1, B3,...) comprises B pictures that are predicted from B pictures of the plurality of lower-layer pictures; the decoding time for each picture is determined such that decoding times of the plurality of lower layer pictures (10, B2, P4,...) are spaced at regular intervals; and the decoding time of each picture in each of the random access units is determined such that all the pictures of the random access unit can be decoded without referring to a picture included in another random access unit, except for a picture which is to be displayed earlier in display order than a leading picture of the random access unit and which is after the leading picture in decoding order, wherein the leading picture is an I picture. determining, for each picture of the plurality of pictures (10, B1, B2, B3, P4,...), a respective decoding time; encoding each of the plurality of pictures (10, B1, B2, B3, P4,...) in accordance with an encoding order according to the determined respective decoding times; and generating an encoded stream including the plurality of encoded pictures and the determined respective decoding times for the plurality of pictures (10, B1, B2, B3, P4,...), characterized in that the plurality of highest layer pictures (B1, B3,...) comprises B pictures that are predicted from B pictures of the plurality of lower-layer pictures; the decoding time for each picture is determined such that decoding times of the plurality of lower layer pictures (10, B2, P4,...) are spaced at regular intervals; and the decoding time of each picture in each of the random access units is determined such that all the pictures of the random access unit can be decoded without referring to a picture included in another random access unit, except for a picture which is to be displayed earlier in display order than a leading picture of the random access unit and which is after the leading picture in decoding order, wherein the leading picture is an I picture.