H.264帧内预测与帧间块模式选择快速算法

针对H.264帧间预测时的多子块模式选择和帧内预测的多模式选择问题,提出了一种实用的基于统计门限的模式快速选择算法,通过门限设定有效限定了编码模式的选择范围.多组视频序列的实验结果表明,基于统计门限的帧内预测模式选择算法在Ⅰ帧的PSNR值有微小变化的情况下,大大降低了编码时间,Ⅰ帧的编码时间降低17%～23%,PSNR下降不到0.4%.基于统计门限的帧间块模式选择算法使得平均PSNR值下降了0.047dB(PSNR最大下降不到1%),但是相对全模式预测时,编码器速度提高了20%～30%.

H.264 inter-frame sub-block mode and intra-frame mode selection algorithm

Since H.264 inter-frame encoding with multi-size sub-block modes and intra-frame encoding with multi-mode involved much calculation, a novel algorithm for H.264 inter-frame sub-block mode selection and intra-frame mode selection based on statistic threshold was proposed. Scale of all the modes was restricted via statistic threshold. Simulation experiment results from video sequences show that the encoding time ofl frame decreases by 17% to 23% and PSNR decreases less than 0.4%. The encoding time of P frame was reduced by 20% to 30% contrasted with that of all sub-block modes, This algorithm is effective in enhancing encoding speed with PSNR lower 0.047dB at most.