One rate control method for low bit rate video communications

With the further progress of video service in fields such as the Internet, and wireless environments in which bandwidth is limited, low rate video coding is increasingly important. Aimed at this kind of application, a new rate control scheme which uses a linear source model is proposed in this study. The optimization criterion is to minimize the variance of MB quantization parameters while subject to the constraint of rate. This method makes the quantization parameters and MSE more concentrated among MB, which leads to more consistent visual quality. At the same time, the overhead bits used to show the changes of quantization parameters between MB are decreased dramatically, which is the desired feature in low bit rate applications. Simulation results show that our proposal can improve PSNR as well as subjective visual quality in low bit rate video applications.