| 摘要 |
METHOD, SYSTEM AND COMPUTER PROGRAM PRODUCT ARE PROVIDED FOR DYNAMICALLY DETERMINING GROUP OF PICTURE (GOP) SIZE AS A FUNCTION OF PICTURE CHANGE ACTIVITY WITHIN A SEQUENCE OF VIDEO FRAMES. IMAGE STATISTICS ON ONE OR MORE INTRAFRAME CHARACTERISTICS OF THE SEQUENCE OF VIDEO FRAMES IS COMPARED TO A PRESET THRESHOLD FOR DECIDING WHETHER TO CONTINUE WITHIN AN EXISTING GOP OR TO BEGIN A NEW GOP. A FRAME OF THE SEQUENCE OF VIDEO FRAMES IS INTRA-CODED, AND EACH OF A VARIABLE NUMBER OF SUBSEQUENT FRAMES IS BI- DIRECTIONALLY PREDICTIVE-CODED (B). EACH B FRAME SUBSEQUENT TO THE I FRAME IS ENCODED EMPLOYING FORWARD PREDICTION MOTION ESTIMATION ONLY FROM THE I FRAME. WHEN A PREDEFINED PICTURE DEGRADATION OCCURS, A NEW GOP IS INITIATED. ONE EXAMPLE OF AN INTRAFRAME CHARACTERISTIC TO BE MONITORED IS THE NUMBER OF INTRA-CODED MACROBLOCKS WITHIN EACH B CODED FRAME. THIS NUMBER IS COMPARED AGAINST A THRESHOLD NUMBER, WHICH MAY BE A PERCENTAGE OF THE TOTAL NUMBER OF MACROBLOCKS WITHIN THE FRAME. |
