分析了场景切换下 TM5码率控制算法失效的原因 ,指出 P、B帧预测效果下降及 I、P帧目标比特数计算误差加大是导致图像编码质量下降的主要因素 .提出了基于场景切换检测和视觉时域掩盖效应的码率控制策略 ,并在场景切换时对 TM5算法得到的目标比特数进行了修正 .实验表明 ,该方法可以在保证碥码缓冲区不发生上溢的前提下改善切换点及后续帧的图像编码质量 The reasons for the failure of the TM5 rate control algorithm under scenario switching are analyzed. It is pointed out that the decrease of the prediction performance of P and B frames and the increase of the number of target bits in I and P frames are the main factors leading to the degradation of the image coding quality. And the rate control strategy of visual time-domain masking effect, and the number of target bits obtained by TM5 algorithm is modified during the scene switching.Experiments show that this method can improve the switching while guaranteeing that the code buffer does not overflow Image coding quality of point and subsequent frames