On the error distribution and scene change for the bit rate control of MPEG

An improved MPEG (Motion Picture Experts Group)-based adaptive bit rate control algorithm that utilizes the predictive and delta modulation techniques in the regulation of quantization parameters is proposed to smooth the error distribution in the picture layer as well as in the macroblock layer. The algorithm allocates bit hierarchically, first for the second layer and then for the picture layer, and finally for the macroblock layer to ensure that both accurate bit rate and stable picture quality can be achieved. The influence of scene change is also analyzed, and a strategy to avoid picture degradation due to incorrect bit allocation after scene change is proposed. The strategy simply stops picture complexity propagation which causes an erroneous estimate of used bit in the next group of pictures after scene change. In experimental situations, the algorithm has produced more stable picture quality and a more accurate bit rate in the macroblock layer than MPEG. The only overhead to implement this algorithm is a frame delay to logically allocate bits in the macroblock layer by picture content and hence can be ignored.<
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