关键词: H.264/AVC, 帧内预测, 模式选择

Abstract: H.264/AVC uses the rate distortion optimization method to determine the best mode for a macroblock （MB） to improve coding efficiency. But it increases computational complexity. To overcome this shortcoming, a fast intra mode decision algorithm for H.264 is raised. In chroma prediction, four prediction modes can be reduced into one or two modes according to the textural features of a MB. In luma 16×16 prediction, the mode which has lowest Sum of Absolute Transformed Difference（SATD） can be selected as the best prediction mode. In luma 4×4 prediction, the algorithm chooses three probable modes from nine modes as the candidate modes. Comparing the total cost of sixteen 4×4 blocks and one 16×16 block, the best block size can be determined. Experimental results show that the coding time of the propose method is decrease about 68% while maintaining similar PSNR and bit rate performance of H.264 intra encoding.

Key words: H.264/AVC, intra prediction, mode select