H.264帧间模式选择新算法

基于H.264视频序列连续2帧时间与空间邻域内已编码宏块(MB)的模式上下文信息，自适应地为当前编码宏块选择合适的候选模式类. 把亮度16×16块和8×8块各自包含的4×4残差子块的变换系数绝对值和组成2个矩阵，利用在其上定义的梯度值分别设计了新颖的宏块级和亚宏块级模式选择准则. 实验结果表明，与joint video team(JVT) J033和JVT K021中提出的模式选择快速算法相比，本算法分别平均节省了近11％和7％的编码时间，而几乎没有带来编码率失真性能损失.

A Novel Mode Selection Algorithm for H.264 Inter Frames

The suitable mode class is adaptively selected for the current macroblock (MB) based on the context of encoded MB modes in the spatiotemporal neighborhoods of the previous and current H264 video frames. Two matrixes which are composed of sum of absolute values of the integer transform coefficients in 4×4 residual block contained in luminance 16×16 block and 8×8 block are defined respectively, the novel MB and sub MB mode selection criteria which use the derived gradients of the two matrixes are then proposed. Experiments show that the proposed algorithm can averagely save about 11% and 7% encoding time compared to joint video team (JVT) J033 and JVT K021 respectively with almost no rate distortion efficiency degradation.