Moving picture data decoding apparatus

摘要

A moving picture decoding apparatus to which this invention is applied is a moving picture decoding apparatus adapted for decoding coded data obtained by predictive coding to reproduce picture data, and includes frame memory 46 having capacity corresponding to three frames for storing picture data of I picture, P picture and B picture reproduced at adder 45 by write address from address generating circuit 52. Motion compensating circuit 47 reads out picture data of I picture or P picture stored in the frame memory 46 as picture data of predictive picture for decoding to deliver it to adder 45, and to read out, by raster address from frame memory display control circuit 53, picture data from frame memory 46 in order of display to output the picture data thus read out. Thus, capacity of frame memory 46 can be reduced and the cost can be also reduced as compared to the conventional moving picture decoding apparatus. In this moving picture decoding apparatus, write and read-out operations of picture data of frame memory 46 are such that picture data of current frame are read out from frame memory 46 in order of display at a timing delayed by substantially one field from writing start time of picture data of current frame into frame memory 46 and is outputted therefrom, that writing start time of picture data of current frame into the memory is caused to be time after 8 horizontal scanning periods of vertical blanking end time between the first and second fields of the former frame, and that writing end time of picture data of current frame into the memory is caused to be time before 8 horizontal scanning periods of vertical blanking start time between the first and second field of current frame.