基于通用串预测算法的AVS2屏幕混合内容帧间编码优化  

Universal String Prediction-Based Inter Coding Algorithm Optimization in AVS2 Mixed Content Coding

作　　者：赵利平[1,3] 林涛[2] 郭靖[2] 周开伦[2] ZHAO Li-Ping;LIN Tao;GUO Jing;ZHOU Kai-Lun(Department of Computer Science and Engineering,Shaoxing University,Shaoxing,Zhejiang 312000;Institute of VLSI,Tongji University,Shanghai 200092;College of Mathematics,Physics and Information Engineering,Jiaxing University,Jiaxing,Zhejiang 314000)

机构地区：[1]绍兴文理学院计算机科学与工程系,浙江绍兴312000 [2]同济大学超大规模集成电路研究所,上海200092 [3]嘉兴学院数理与信息工程学院,浙江嘉兴314000

出　　处：《计算机学报》2019年第10期2190-2202,共13页Chinese Journal of Computers

基　　金：浙江省自然科学基金项目（LY19F020015）;国家自然科学基金项目(61871289,61601200）;绍兴市公益性技术应用研究计划项目（2018C10015）;上海市自然科学基金项目（18ZR1440600,19ZR1461100）资助~~

摘　　要：我国第二代数字音视频编解码技术标准的屏幕与混合内容扩展版(AVS2-SMCC)中,对于全色度屏幕混合内容的编解码其采用融合4∶4∶4格式的通用串预测编码算法和传统4∶2∶0格式的块预测、变换编码算法的编解码框架.在此框架中,根据屏幕混合内容的内在帧间特性和不同帧间子模式的特点,该框架对帧间编码算法进行了优化:首先提出了支持4∶4∶4格式的帧间编解码算法;其次,提出了内容自适应的不同帧间子模式色度失真权重因子算法和帧间子模式预编码与编码树单元划分的提前终止算法;最后,提出了一种新的帧间第一受限串模式,即将通用串预测算法的第一受限串的参考位置扩展至参考图像队列中的第一帧.实验结果表明,对于AVS2-SMCC标准测试序列中的移动文本和图形类别序列,提出的算法和AVS2-SMCC参考软件RMD1.0相比,在有损低延迟配置(一种含帧间编码的配置)下,Y、U、V分量的平均BD-rate下降率分别可达14.35%、90.73%、88.85%,编码时间降低50.86%,解码时间增加15.24%.With the rapid development of technologies in networking and thin-client devices,such as remote desktop,video conferencing with documents or slides sharing,television programs and many curriculum videos playing in the Internet that contain mixtures of camera-captured content(CC)and screen content(SC),efficient screen content coding(SCC)becomes a hot topic in multimedia applications and has attracted increasing researcher attention from both academia and industry.Two international video coding standards include efficient SCC capability.One is High Efficiency Video Coding(HEVC),the other is the second-generation of the Audio Video Coding Standard(AVS2).In recent years,AVS is developing an AVS2 Screen and Mixed Content Coding(SMCC)extension(AVS2-SMCC).In our previous work,a 4∶4∶4 format universal string prediction(USP)algorithm integrated with the tradition 4∶2∶0 format block prediction and transform coding framework is used to code 4∶4∶4 format mixed content screen.To fully exploit both local and non-local,both general and special,and both complex and simple matching patterns with a variety of sizes and/or shapes and/or positions in a wide range of commonly seen screen content,a USP approach and its key technologies with three modes:general string(GS)mode,constrained string 1(CS1)mode,and constrained string 2(CS2)mode are proposed.The three constrained string modes are implemented with one of the three types of strings:offset string,coordinate string,and unpredictable pixel,or its combination of them.When using USP algorithm to code a coding unit,one of the three constrained modes which gets the minimum rate distortion value is selected to code the CU.Experimental results show that,for text and graphics with motion of AVS2-SMCC test sequences,USP algorithm achieves significantly improved coding efficiency in the All Intra configuration when compared with the latest HEVC-SCC extension.In order to further improve the coding efficiency in the Low Delay configuration and reduce the complexity,in this framew

关 键 词：高效视频编码 音视频编解码技术标准 屏幕混合内容编码 帧间编码 快速算法 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]