基于SVC与多网络接口的DASH调度算法  

DASH Scheduling Algorithm Based on SVC and Multiple Network Interfaces

作　　者：韩煦 张国强[1] 高茜[1] HAN Xu;ZHANG Guoqiang;GAO Qian(School of Computer Science and Technology,Nanjing Normal University,Nanjing 210023,China)

机构地区：[1]南京师范大学计算机科学与技术学院

出　　处：《计算机工程》2019年第12期243-248,共6页Computer Engineering

基　　金：国家自然科学基金(61772279,41771411);江苏省研究生科研与实践创新计划(KYCX18_1237);赛尔网络下一代互联网技术创新项目(NGII20150102)

摘　　要：基于HTTP的动态自适应流媒体(DASH)技术是主流的互联网视频传输技术之一,可适应动态网络和异端客户端,然而传统DASH使用高级视频编码(AVC),存在编码块复用性低、码率波动性高等问题。为此,在终端设备具有多网络接口的环境下,以可伸缩视频编码(SVC)代替AVC,提出一种基于视频块优先级的联合调度算法。通过SVC编码将整个缓冲区组织为一个包含时间维度和编码层次维度的二维空间,确定视频块在二维缓冲区的位置,将其放入待下载队列,并按照优先级对队列中的视频块进行重新排序。根据每个网络接口的带宽,将队列中的视频块分配给不同接口执行下载操作。实验结果表明,相比于单接口基于带宽和缓冲的调度算法,该算法的平均视频质量提高46.04%,切换次数降低36.84%,并且可使缓冲水平下降44.11%。The Dynamic Adaptive Streaming over HTTP(DASH)is one of the mainstream Internet video transmission technologies,which can adapts to dynamic networks and heterogeneous clients.However,the traditional Advanced Video Coding(AVC)based DASH has many problems such as low reusing ratio of code block and high rate of oscillation.Under circumstances where the terminal equipments have multiple interfaces,this paper replaces AVC with Scalable Video Coding(SVC)and proposes a joint scheduling algorithm based on video block priority.First,the SVC organizes the whole buffer into a two-dimensional space,containing the time dimension and the coding hierarchy dimension.Then the video blocks in the two-dimensional buffer are located,put into the download queue and rearranged according to their priority.Finally,the video blocks in the queue are allocated to different interfaces to execute download operations according to the bandwidth of each network interface.Experimental results show that compared with the single-interface,bandwidth and buffer-based scheduling algorithm,the video quality of the proposed algorithm improves by 46.04%in average,the switch times reduces by 36.84%and the buffer level decreases by 44.11%.

关 键 词：可伸缩视频编码 多网络接口 流媒体技术 DASH技术 调度算法 

分 类 号：TP37[自动化与计算机技术—计算机系统结构]