An improved rate control algorithm for H.264

This paper proposes a new algorithm for H.264 rate control, and aims at improving coding quality of high motion scenes. Firstly, the motion estimations using all the possible modes are performed, and the mode that produces the least mean absolute difference is used to estimate the quantization parameter. Secondly, a new motion complexity measure is defined to represent the amount of motion content between two consecutive frames, and is used to estimate the target bit. Experimental results show that our scheme can effectively improve video quality at scene changes and high motions, and reduce the sharp drops of PSNR as compared with the H.264 adopted rate control algorithm. Moreover, our scheme also achieves an average PSNR gain of 0.129 dB for the test sequences.