关键词: H.264, 码率控制, 平均绝对差, 基本单元

Abstract: Rate control plays a dominant role in getting the higher video reconstruction quality in given bandwidth.In order to improve the rate control performance of H.264，a novel rate control algorithm is presented in this paper.First，the Quantization Parameter（QP） of the I-frame is determined by using a linear PSNR-QP model.Then，the QP of the P-frame is calculated from H.264’s quadratic R-Q model.Different from H.264，the predicted MAD is calculated by a combined space-time model，i.e.，the combination of linear prediction model and the weighted model，and adaptively corrected according to prediction errors.Experimental results have shown that the reconstructed frames by the proposed algorithm can achieve better reconstruction performance and less fluctuation than by JM10.2 in terms of PSNR.

Key words: H.264, rate control, Mean Absolute Difference（MAD）, Basic Unit（BU）