An Improved Rate Control Scheme for H, 264 Based on Frame Complexity Estimation

The JVT-G012 rate control algorithm for H.264 video encoding can get high encoding efficiency. But the algorithm has disadvantage that the target bit allocation in the frame layer is uniform according to the buffer residual bits. This paper presents a new method which uses a content complexity quotiety of frame for allocating target bits in the frame layer more accurately. The content complexity quotiety is the combination of the average difference of gray histogram and mean absolute difference (MAD) ratio in the frame. Experimental results show that the bit rate maximum error of tested sequences in this algorithm is 1.38 percent and their average peak signal noise ratio (PSNR) is improved by 0.38 dB on average compared to the original JVT-G012 algorithm. Therefore, the proposed rate control algorithm can not only more accurately control bit rate, but also improve PSNR of video sequences. The video image quality is better and smoother.