基于场景突变的码率控制算法  

A rate control algorithm based on scence change detection

作　　者：吴军[1] 林伟华[1] 谢斌[1] 

机构地区：[1]江西理工大学信息工程学院,江西赣州341000

出　　处：《江西理工大学学报》2015年第3期89-94,共6页Journal of Jiangxi University of Science and Technology

基　　金：江西省教育厅青年科学基金项目(GJJ11132)

摘　　要：在视频编码中实际的视频序列一般是由不同的场景组成,在场景突变处,由于前后两帧在不同的场景中,空间相关性减小,导致视频编码质量下降,码率控制偏差较大.为了解决H.264视频编码中因场景突变而导致的编码质量下降等问题,提出一种改进的码率控制算法.用图像信噪比比值检测场景突变,在场景突变处提前结束编码当前GOP,将当前GOP未编码帧和下一个GOP合并为一个新的GOP,并修正码率分配.仿真结果表明,新算法在不增加编码器复杂度的前提下可以精确检测场景突变,提高后续帧的编码质量,减少编码时间.The video sequence in video decrease in the position of scene change coding is usually composed of different scenes. Spatial correlation may of the sequence because the two frames are in different scenes, which leads to a sharp decrease in video quality and a large rate control deviation. In order to effectively solve the problem of decreasing video quality because of scene change in H.264 video coding, an improved rate control algorithm is put forward in this paper. In the experiment, scene change was detected with the average difference of gray value first, then current GOP was stopped coding in the place of scene change; unencoded frames on current GOP was combined with the next GOP into a new GOP; rate allocation was adjusted in the last. The simulation results show that the proposed increase of the encoder complexity, improve the encoding time. algorithm can precisely detect scene change without any video quality of subsequent video frames and decrease the encoding time.

关 键 词：H.264 码率控制 场景突变 码率分配 

分 类 号：TN919.81[电子电信—通信与信息系统]