改进的帧内帧间模式选择快速算法

为提高I帧和P帧的编码效率,H.264视频编码标准采用多模式帧内预测和多子块模式帧间预测,并选择率失真最优的模式进行编码,导致编码复杂度很高.为此,提出一种基于小波变换的帧内模式快速选择结合帧间预测下帧内模式预判断的算法.利用小波变换后的低频子图做帧内模式选择,由此预判断宏块中每个4×4子块可能的预测模式,使原来9次的代价函数计算减少到平均3.75次;使用去均值的差值平方和,预判断宏块是否选择帧间预测下的帧内编码模式,减少P帧编码时间.实验表明,改进算法在峰值信噪比降低不超过0.0644dB的情况下,编码速度平均提高19%左右.

Fast mode selection for intra and inter prediction

H.264 video coding standard is high complex and time-consuming owing to its multi-mode in intra prediction and multi-size sub-block modes in inter prediction to improve the efficiency of I frame and P frame.A new algorithm with fast mode selection based on wavelet transforms in intra prediction and combined with pre-estimation of intra mode in inter prediction was proposed.Firstly,the method utilized the optimal modes selected in low frequent part transformed by wavelet to estimate the possible modes in sub...