H.264/AVC是最新的视频压缩编码标准，在帧内预测过程中，采用了率失真优化技术(RDO)进行预测模式的选择，使编码性能得到显著提高，但同时编码复杂度和计算量也明显增加。研究了现有的典型快速帧内预测算法，并提出一种融合宏块平坦性特征和4×4块纹理特征的快速帧内预测算法。算法通过判断宏块的平坦性提前选定块大小，根据4×4块内部纹理特征，确定预测模式集，降低算法复杂度。实验结果表明，较之JM95，在峰值信噪比(PSNR)基本不变，输出码率略有升高的情况下，本文算法对一个宏块的RDO计算次数平均降低了71.3%。

H.264/AVC is the newest video compression coding standard. The intra prediction for H.264 uses RDO to choose the best prediction mode. This makes the coding performance greatly enhanced. But it also causes the coding complexity and the computation obviously to increase. This paper studies several fast intra prediction algorithms, and proposes a novel fast intra prediction algorithm which fuses the macroblocks smooth character and the 4×4 blocks texture property. The algorithm pre decides the size of block by macroblocks smooth character and decreases the predict modes by the texture character of 4×4 block. The result compared with JM95, shows that the algorithm makes the coding complexity reduced 71.3% while the PSNR is almost invariable.