IMAGE DECODING APPARATUS AND IMAGE DECODING METHOD

摘要

A stream dividing unit is included which divides each of a plurality of pictures included in an encoded stream into a plurality of MB lines and allocates the MB lines to any ones of a plurality of divided streams, thereby providing the plurality of divided streams that can be decoded in a parallel manner.  In the stream dividing unit, when each of a plurality of slices included in each picture is divided into a plurality of slice portions and the slice portions are allocated to the plurality of divided streams, slice portion groups, each of which consists of a plurality of slice portions allocated to the divided streams, are rearranged for each divided stream such that those slice portion groups can be recognized by a decoding apparatus as slices.  In the rearrangement, when two consecutive MB lines have a dependence on each other in terms of a predetermined code word (for example, QP value variation or MB skip-run information), a code word is set for each divided stream such that the dependence is changed to a new dependence that is in accordance with a fore-and-aft relationship between MB lines in each divided stream.