Motion video predict coding method, motion video predict coding device, motion video predict coding program, motion video predict decoding method, motion predict decoding device, and motion video predict decoding program

A video predictive decoding method executed by a video predictive decoding device, comprising:

• inputting (i) a compressed form of picture data for reproduction of a target picture[k], the compressed form of picture data resulting from execution of predictive coding on the target picture[k], using a first set of reference pictures, and (ii) a compressed form of buffer description information BD[k] that describes the first set of reference pictures used to predictively encode the target picture[k], wherein the first set of reference pictures are described in the buffer description information BD[k] with their identification numbers relative to identification numbers of a second set of reference pictures described in buffer description information BD[m] which are used to reproduce another target picture[m] different from the target picture[k];
• decoding the compressed form of picture data to reproduce the target picture[k];
• and
• storing the reproduced target picture[k] as a reference picture to be used for decoding of a subsequent target picture,
• wherein decoding the compressed form of picture data to reproduce the target picture[k] comprising:
• prior to reproducing the target picture[k], referencing the buffer description information BD[m] to restore the identification numbers of the first set of reference pictures described in the buffer description information BD[k], wherein the buffer description information BD[m] (m=k−1) immediately precedes the buffer description information BD[k], and
• wherein referencing the buffer description information BD[m] to restore the identification numbers of the first set of reference pictures described in the buffer description information BD[k] comprises:
• restoring a value of deltaBD representing a difference between identification numbers of corresponding reference pictures described in the buffer description information BD[m] and the buffer description information BD[k];
• restoring a plurality of flags ibd_flag[j] each adapted to take multiple values one of which is indicative of both:
• (a) whether or not an identification number of a j-th reference picture described in the buffer description information BD[m] is used for restoration of an identification number of a reference picture described in the buffer description information BD[k];
• and
• (b) whether or not the j-th reference picture described in the buffer description information BD[m] is used for reproduction of the target picture[k], and
• restoring the identification numbers of the first set of the reference pictures described in the buffer description information BD[k] using an index m (m=k−1) that identifies the immediately preceding buffer description information BD[k−1], the restored value of deltaBD and the restored flags ibd_flag[j].