通用率失真模型及码率控制算法*

为了提高码率控制的准确性，通过实验和理论推导，提出了一种通用率失真模型。在此基础上，定义了纹理复杂度，提出了纹理复杂度和图像块头用字节两自适应线性预测模型及宏块（组）比特分配模型；然后结合以上模型提出了一种新的码率控制算法。大量仿真实验结果表明，利用新提出的码率控制方法，测试序列的PSNR均有不同程度的提高，且码流曲线更平滑平稳，目标码率控制更准确。

General rate distortion model and rate control scheme

To improve the accuracy of rate control,proposed a new general rate distortion model on the basis of theoretical analysis and extensive experiments.Meanwhile,this paper defined texture complexity,presented optimistic bit allocation model and two adaptive linear predictive models:texture complexity and overhead bit count predictive models. Based on above models,proposed a new rate control scheme for low bit-rate and real-time video coding applications.Simulation results show that the new rate control algorithm provides smoother bit stream, higher video quality and more accurate rate control than previous algorithms.