Patent ID: 7221803

Claim:
A decoding method for decoding a data stream, the data stream being obtained by coding a moving image including a plurality of pictures, wherein the data stream includes: a coded first picture generated by coding a first picture, coded management information data generated by coding first memory management information for managing a reference picture stored in a memory, the first memory management information being attached to the coded first picture, and re-coded management information data generated by coding the first memory management information again as second memory management information, the second memory management information being attached to a second picture which is different from the first picture, said method comprising: extracting the second memory management information; and performing the following based on the extracted second memory management information: (i) releasing an area of a decoder memory which holds an unnecessary picture and which is therefore to be released, when the area has not yet been released, and (ii) executing no processing on the decoder memory when the area has already been released based on the first memory management information.