一种基于H.264的全零模块预判算法

An Efficient Early Detection Algorithm for All-Zero Blocks Based on H.264

在低比特率视频压缩编码中，全零模块的预判是一种用来减少编码器计算复杂性的技术。在对离散余弦变换（DCT）和量化的理论分析基础上，提出了一种基于H．264视频编码的全零模块预判的改进算法，该方法在整数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差值和（SAD）及量化参数而定。实验结果表明，与传统的方法相比，在不造成视频质量下降的情况下该方法运算量减少了16%～32%。

Aim. In low bit-rate video coding, all-zero block determination is a common technique to reduce the computational complexity of the encoder. We aim to improve the algorithm for the early detection of all-zero blocks in H. 264 video encoding. We explain in detail our improvement in the full paper; in this abstract, we just add some pertinent remarks to listing the two topics of explanation： （A）early detection technique in DCT（discrete cosine transform） ; according to the characteristics of integer transformation and motion search in H. 264, all-zero block decision is made in inter-frame coding by comparing sum of the absolute differences （SAD） with a value related to quantization parameter before integer transformation, achieving a large reduction in the amount of computation in transformation and some reduction in the amount of computation in motion search and quantization; although eqs. （1） through （4） are well known, how to use them makes quite a difference in the amount of computation; in topic （A） we discuss how to use them; （B） early detection algorithm for all-zero blocks based on H. 264; in topic （B） we derive eqs. （5） through （9）. Finally we give a numerical simulation example, whose results are given in Tables 1 and 2 in the full paper. These results show that the proposed algorithm achieves approximately an 11%-36% computational saving without video-quality degradation, as compared with the conventional method.