分布存储媒体传输的同步算法

分布多媒体数据库（ＤＭＤＢ）和分布多媒体信息系统（ＤＭＩＳ）的一个重要需求是多媒体同步传输．文中先分析了在ＤＭＤＢ和ＤＩＭＳ中多媒体同步传输的特点和要求，然后提出了一个能满足这些要求的同步传输方案．在这个方案中，多媒体同步关系是用动态同步Ｐｅｔｒｉ网（ＤＳＰＮ）来显式描述的；通过文中给出的同步传输算式和同步发送算法，可以在ＤＳＰＮ模型的基础上产生同步传输调度方案；同时接收端能根据实际通信状况和多媒体的同步要求，对来自多个服务器的多媒体对象进行动态同步控制．

SYNCHRONIZATION ALGORITHMS FOR DISTRIBUTED STORED MULTIMEDIA TRAFFIC

Multimedia synchronization traffic has been identified as an important requirement of distributed multimedia databases (DMDB) and distributed multimedia information systems (DMIS). The characteristics and requirements of multimedia synchronization traffic in DMDB and DMIS are discussed in the paper. Then, a synchronization traffic scheme is presented to meet these requirements. In the scheme, the multimedia synchronization relationships are specified expressively by using dynamic synchronization Petri net (DSPN). From DSPN, the synchronization traffic schedule can be generated by employing the suggested synchronization transmitting equations and synchronization transmission algorithms. According to the practical communication status and the requirements of multimedia synchronization, the client is allowed to control dynamically multimedia synchronization of multimedia objects coming from multiple servers.