多媒体同步系统中补偿缓冲区的设计  

Compensation buffer design in multimedia synchronization systems

作　　者：许延[1] 常义林[1] 刘增基[1] 

机构地区：[1]西安电子科技大学综合业务网国家重点实验室

出　　处：《西安电子科技大学学报》2003年第3期315-319,398,共6页Journal of Xidian University

基　　金：教育部高校博士学科点专项科研基金项目(20010701006);ISN国家重点实验室资助项目

摘　　要：多媒体系统中端到端的时延抖动常常导致媒体播放的不连续,为了保持媒体内及媒体间的时间关系,通常在信宿端设置缓冲区来补偿时延抖动,将时延抖动和时延偏移限制在一定的范围内.文中分析了时延抖动的统计特性,它近似于高斯分布,在此基础上提出了一种缓冲区的设计方法.另外给出了包含音频和视频多媒体播放系统的同步应用,利用Chernoff不等式,推导出所需缓冲区大小的计算公式.模拟结果表明,用该方法确定的缓冲区完全能够满足用户提出的可感知的服务质量(P QoS),而且具有较高的缓冲区利用率.In multimedia systems end-to-end delay jitter often leads to discontinuity of information playback. Therefore a mechanism which maintains the jitter and skew variations bounded within suitable values must be adopted in order to preserve the intra-media and inter-media temporal relationships. A buffer at the destination site is often adopted to compensate the delay jitter. Based on the statistical analysis of the delay jitter that is near Gaussian distribution, a method for designing a compensation buffer is presented. In this method, the buffer size can be determined according to its relationship with perceivable quality of service (P_QoS). A synchronization case study is also included, which adopts the Chernoff bound so that the buffer required can be presented in a simple formula. Finally simulation results show that the method of buffer determination is effective. With this method, synchronization system can always meet the P_QoS defined by the user. Additionally, it also has high buffer utilization and satisfies end-to-end delays.

关 键 词：多媒体同步系统 时延抖动 缓冲区 时延偏移 P_QoS Chernoff不等式 

分 类 号：TN919.8[电子电信—通信与信息系统]