H.264中的基于全零块检测的运动搜索方法

Motion Search Method Based on All Zero Block Detection in H.264

运动搜索和变换域编码是视频编码标准H.264中运算量很大的部分,为了减少视频编码的运算量,本文根据H.264运动搜索和整数变换的特征,提出了一种H.264下的全零块检测方法。在帧间编码中,该方法在运动搜索中和变换前,对运动补偿的差值数据进行全零检测,检测的门限根据绝对误差和(SAD)和量化参数而定。在运动搜索非常准确时,就可以找到全零块,就停止搜索,可以省却后面的搜索运算和全零块的整数变换以及相应的量化运算,在基本保持H.264原有编码算法的图像质量的同时,减少了运算量,缩短了码流,提高了编码器的编码效率。

In order to reduce the computation of motion search and transformation in H.264 encoder, an all-zero block detection method based on integer transform and motion search is proposed in this paper. According to the characteristics of integer transform and motion search in H.264, all-zero block decision is made in inter-frame coding by comparing Sum of the absolute differences(SAD) to a value related with quantization parameter before integer transformaion, avoiding a large amount of computiaon in motion search, tansformation and quantization. This technology highly improves the efficiency of real time H.264 encoder by skiping all-zero block before integer transformaion and shortens the code stream at the same time.