一种高效的H.264码率控制方法

针对H．264编码方案提出了一种实时的无需二次编码的比特分配和码率控制策略．在一个可以在模式选择前预测当前帧编码复杂度的码率模型基础上给出基于宏块条的码率控制策略，包括帧、宏块条的比特分配和量化级计算方法以及求取码率模型参数的自适应算法，并对场景切换进行了检测和处理．实验结果表明，与JVT提案中部分使用二次编码的码率控制方法JVT-E069相比，所提出的方法在相同条件下码率控制得更准确，并能获得较高的PSNR和主观视觉质量，特别在有场景切换的情况下PSNR可提高0．5dB．

A Novel Rate Control Method for H.264

This paper presented a real-time single-pass bit allocation and rate control method for H.264. In order to solve the rate control problem for the fact that the quantization parameters are used in mode selection, a rate model was presented which can estimate the frame coding complexity before macroblock mode selection. Based on the rate model, a slice layer rate control scheme was developed, including bit allocation of the frame layer, the slice layer and the quantization parameter calculation method. At last, the problem of scene changes was solved. The experiments show that, compared to JVT-E069 which is partially two-pass, this method can control the rate more accurately and obtain the higher PSNR and visual quality. Especially when the two schemes are applied to the sequence with scene changes, the PSNR is improved by (0.5 dB).