低比特率视频编码中一种有效的码率分配算法  

Efficient Bit Allocation Scheme in Low Bit Rate Video Coding

作　　者：周树民[1] 李锦涛[1] 黄晁[1] 

机构地区：[1]中国科学院计算技术研究所数字化技术研究室,北京100080

出　　处：《计算机辅助设计与图形学学报》2005年第11期2558-2564,共7页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家自然科学基金(60302028)

摘　　要：引入能较好地反映视频图像运动特性的差分帧直方图(HOD)来预分配码率.对于运动较为平稳的序,提出了基于HOD的分段常数码率预分配算法.帧级码率预分配根据视频原始序列HOD的统计特性来决定;对于运动程度变化较大的序列,采用修正后的线性HOD模型来预分配码率.实验结果表明,相对于H.264 JM76中的分配算法,该算法使得R-D性能平均提高0.35 dB,视频主观质量的下降也得到了有效的改善.Histogram of differential frame （HOD） was introduced to allocate bits on frame level since it could indicate the motion degree of a picture effectively. Based on HOD pre-analysis, a frame-layer bits allocation scheme is proposed to replace the one used in AVC. In the scheme, a new model of sectional constant frame-layer bits allocation is proposed when motion distribution in a sequence is continuous. Otherwise, a revised linear HOD model is used to allocate bits for a frame if there is abrupt motion change. The final simulation shows that compared to H.264 JM76, the proposed bits allocation scheme improves R-D performance by 0.35dB on average and manifests a more smooth subjective quality degradation.

关 键 词：比特预分配 码率控制 差分帧直方图 

分 类 号：TP391.71[自动化与计算机技术—计算机应用技术]