Patent ID: 6414993
Filing Date: 2002-07-02
Classification: H04N

Abstract:
A decoding system for producing pieces of video data information representative of plural kinds of pictures to be reproduced on a screen of a display from compressed data streams having bit strings representative of said plural kinds of pictures and coded through an inter-frame predictive coding technique, comprising:plural memories respectively assigned to said compressed data streams, each of said plural memories having plural frame memories more than frame memories required for producing any one of said pieces of video data information; a decoding section selectively supplied with said bit strings of said compressed data streams, and producing output signals representative of said pieces of video data information and a first control signal representative of one of said plural kinds of picture represented by the bit string just processed; an information processor connected to said decoding section, producing the pieces of video data information from said output signals or through an information processing between the pieces of video data information represented by said output signals and the pieces of video data information already stored in said plural memories, and storing each of said pieces of video data information in one of said plural frame memories of the associated one of said plural memories; a controller responsive to said first control signal so as to select one of said plural frame memories of associated one of said plural memories, and instructing said information processor to transfer the piece of video data information produced from said bit string just processed to said one of said plural frame memories for replacing an invalid piece of video data information already stored therein with said piece of video data information; and a synchronous signal generator producing a first synchronous signal supplied to said controller and a second synchronous signal supplied to said display for reading out said piece of video data information; wherein said compressed data streams are coded on the basis of standards of motion picture experts group, and said plural kinds of pictures are an I-picture coded in a frame without any piece of video data information in a different frame, a P-picture coded in a frame with reference to a piece of video data information in a first predetermined frame before said frame and a B-pictured coded in a frame with reference to a piece of video data information in a second predetermined frame before said frame and a third predetermined frame after said frame; wherein plural pictures selectively categorized in said I-picture, said P-picture and said B-picture are concurrently reproduced on said screen in a single frame period, and said I-picture and said P-picture serve as a core picture; and wherein said controller includes; a timing generator responsive to said first synchronous signal so as to generate plural initiation signals in each frame period at intervals; plural frame memory controllers respectively associated with said compressed data streams and each responsive to said first control signal so as to selectively produce a second control signal representative of one of said of said plural frame memories of the associated memory for writing the piece of video data information thereinto, a third control signal representative of another of said plural frame memories of said associated memory for reading out the piece of video data information therefrom and a fourth control signal representative of yet another of said plural frame memories of said associated memory for reading out the piece of video data information; and an address generator responsive to said second, third and fourth control signals so as to produce address signals selectively supplied to said plural memories.