Patent ID: 6462744
Filing Date: 2002-10-08
Classification: H04N

Abstract:
An image decoding apparatus which decodes pieces of picture data included in a video stream according to an instruction from a host apparatus and writes the decoded pieces of picture data into a storage apparatus, wherein each piece of picture data is of one of a plurality of picture types which are each related to one of different encoding methods, and the storage apparatus includes a plurality of frame areas for storing most recently decoded pieces of picture data separately according to the plurality of picture types, the image decoding apparatus comprising:a decoding means for decoding pieces of picture data included in the video stream one at a time while referring to decoded picture data in at least one of the plurality of frame areas; a writing means for writing a newly decoded piece of picture data over a piece of picture data in one of the plurality of frame areas, an area allocation means for allocating, on receiving a reservation request to reserve a work area in the storage apparatus from the host apparatus, a region in one of the plurality of frame areas as the work area, wherein the region should store either of (1) a certain part of a piece of picture data of a predetermined picture type that is yet to be decoded by the decoding means, and (2) a certain part of a decoded piece of picture data of the predetermined picture type that is yet to be written by the writing means.