为了降低H．264编码复杂度，提出一种基于时空相关性的快速帧内预测算法。该算法充分利用视频序列的时间相关性，自适应地根据先前编码宏块对当前宏块进行预判，在Intra＿4×4和Intra＿16×16预测方式之间进行选择；对Intra＿4×4预测方式，依据模式聚集特性，参考先前帧和当前帧已编码宏块的预测模式统计特征，确定当前4×4子块的候选模式。实验结果表明，该算法在保证信噪比和比特率几乎不变的情况下，编码时间减少约40％，提高了编码效率。 In order to reduce the encoding complexity in H.264,we propose a fast intra-frame prediction algorithm which is based on temporal and spatial correlations.Making full use of the advantage of temporal correlation of video sequence,the algorithm adaptively prejudges current macroblock according to previous coded macroblocks,and selects between the prediction approaches of Intra_4 ×4 and Intra_16 ×16;For Intra_4 ×4 prediction,it decides the candidate modes for current 4 ×4 sub-macroblock according to mode-gathering characteristic and referring the statistic characteristics of prediction mode of coded macroblocks in pre-frame and current frame.Experimental result shows that the algorithm reduces the encoding time by 40% with a neglectable PSNR change and bit rate increase,improves encoding efficiency.In order to reduce the encoding complexity in H.264, we propose a fast intra-frame prediction algorithm which is based on temporal and spatial correlations. Making full use of the advantage of temporal correlation of video sequence, the algorithm adaptively prejudges current macroblock according to previous coded macroblocks, and selects between the prediction approaches of Intra_4*4 and Intra_16*16; For Intra_4*4 prediction, it decides the candidate modes for current 4*4 sub-macroblock according to mode-gathering characteristic and referring the statistic characteristics of prediction mode of coded macroblocks in pre-frame and current frame. Experimental result shows that the algorithm reduces the encoding time by 40% with a neglectable PSNR change and bit rate increase, improves encoding efficiency
