Patent ID: 7346112

Claim:
A video decoding and displaying apparatus comprising: a managing unit that partitions a frame memory into a plurality of sectors, wherein the frame memory stores decoded video data of a frame not used as a predicted video, the decoded video data including a top-field data and a bottom-field data; a write control unit that writes the top-field data and the bottom-field data of the decoded video data into separate free sectors of the frame memory; and a read control unit that, at the time of displaying decoded video data by reading it from the frame memory, simultaneously releases, during a last display field period of a display video, the sector that stores the top-field data and the sector that stores the bottom-field data when the sector capacity of the frame memory is equal to or greater than that required for one frame of video data to be displayed, wherein the decoded video data includes two video data of different picture sizes, and also when the sector capacity of the memory frame is less than that required for one frame of the video data of a larger picture size, the read control unit releases one corresponding sector out of a sector that stores top-field data which has been read and a sector which stores bottom-field data during each display field period, in a reading and a displaying of the video data of the larger picture size, and simultaneously releases the sector that stores top-field data and the sector that stores bottom-field data during a last display field period, in a reading and a displaying of the video data of a smaller picture size.