本文提出了一种简单有效的帧内模式选择方法，通过分析CABAC熵编码中色度分量与量度分量的交织信息，去除耦合，同时在率失真优化过程中部分引入部分码率估计方法，降低模式选择的计算复杂度，提高模式选择速度。大量的实验结果表明，本文提出的方法对全I帧序列能够带来66.4%的时间节省，同时几乎不损失编码图像质量；对IBBP序列能够达到平均10%的时间节省，同时部分序列甚至比JM有更好的R-D曲线。

An easy and efficient intraframe mode decision method is presented in this paper. We analyze the interlace information of the chroma and luma components in the H.264 bitstream after the CABAC entropy coding,and decouples the correlations. The partial bit rate estimation technology which is used in the ratedistortion optimization can reduce the computational complexity and speed up the mode decision process. The experimental results show that the proposed method can achieve timesaving by 66.4% for all intrasequences with almost no loss of picture quality. For the IBBP sequence, an average of 10%  timesaving is also gotten with some better RD curves than that of JM.