A New Rate Control Algorithm for H.264

Rate control plays an important role in real-time video communication application. Extensive experiments show that rho is still linear with the bit rate of a macroblock row in H.264. Based on this conclusion, this paper presents a macroblock row layer rate control algorithm for H.264 via rho -domain source modeling. The scene change is detected by PSNR-based complexity estimation and then a control window is introduced. In this window, the bit allocation is based on the coding hit count of the first rate distortion optimization (RDO) and the target bit count in Li´s method. The macroblock row layer hit allocation of the proposed method is achieved according to the percentage of bit count of each macroblock row in the first RDO. Experimental results show that the proposed rate control algorithm can not only achieve significantly smaller bit rate estimation error while guaranteeing the same coding efficiency, but also effectively improve the coding performance for the sequence with scene change.