【摘要】 本文分别在图像层和宏块层进行 Ｈ２６３ 的码率控制。在图像层采用后向自适应控制的方法，通过引入量化步长因子—编码输出比特数映射表，确定每帧图像量化步长因子的基准值。在宏块层采用前向控制的方法，根据视觉掩蔽特性设计模糊分类器，确定人眼对每个宏块的敏感程度和相应的量化步长因子。能在视频输出码率恒定的条件下，保持图像质量的稳定，取得较好的视觉效果。更多还原

【Abstract】 The bit rate control algorithm proposed in this paper can adjust the quantization step factor Q in both picture layer and macroblock layer.In picture layer,it uses the adaptive backward method to determine the basic value of Q for each frame by the Q N(Quantization step factor Number of output bits)Mapping Table.In macroblock layer,a fuzzy perceptual classifier is used to determine the visual sensitivity of each blcok Based on the result of classification,the quantization step factor of each macroblock is determined.With this control algorithm,the consistent coding quality and good visual effect can be kep under constant bit rate更多还原