一种精细的H.264码率控制方法

针对H.264提出了一种无需二次编码的精细码率控制策略,为解决H.264中宏块模式选择时需要使用量化级而给码率控制带来的困难。提出了一种可以在模式选择前预测当前帧编码复杂度的码率模型。并且提出了基于宏块条的码率控制策略。分析了H.264中利用拉格朗日R D优化方法进行宏块模式选择的特点,并根据编码比特对拉格朗日乘子进行优化,提出了基于模式选择的精细码率控制方法。实验结果表明,与JVT提案中的码率控制方法JVT G012相比,所提方法在准确控制码率的同时,提高了PSNR值。

Fine rate control method for H.264

A fine single-pass rate control method for H.264 is presented. In order to solve the rate control difficulty caused by the fact that the quantization parameters are used in mode selection, a rate model is given which can estimate the frame coding complexity before macroblock mode selection. Based on the rate model, a slice layer rate control scheme is developed. In order to enhance the method with more accuracy, the mode selection process is analyzed and a fine rate control method based on mode selection by optimizing the Lagrange multiplier using coding bits is proposed. The experiments show that compared to JVT-G012 in JVT, the proposed method can control the rate more accurately and the average PSNR of all testing sequences is improved.