CONTROLLING METHOD OF BIT RATIO OF VIDEO

摘要

PURPOSE: To prevent image quality deterioration due to a scene change by controlling bit assignment depending on the presence of the scene change for each SUBGOP being a division of a GOP that is one unit of image information consisting of I, P, B pictures of a required number based on the MPEG standard. CONSTITUTION: A SUBGOP from a video frame input section 1 is given to a coding section 2, where bit assignment is controlled based on a signal from a bit rate control section 4. In this case, the control section 4 checks a scene change between two consecutive SUBGOP sets to discriminate it that a SUBGOP with the scene change is a SUBGOP next to a current SUBGOP. In the case that whether or not a final frame and a current SUBGOP and a final frame of the next SUBGOP are a P frame is checked and the SUBGOP is coded, when there is any scene change, a bit number with respect to a frame with a scene change whose SUBGOP is coded is much assigned depending on a bit filling degree of a buffer section 3. Thus, prescribed coded image information is obtained, where image quality deterioration due to the scene change is prevented.