This paper first expresses a multimedia stream by two instantaneous events according to the CSP(Communicating Sequential Process) theory. Then the concept of time duration vector is defined and some computations on it are considered.

• 该文首先根据通信顺序进程的理论 ；把一个多媒体流用两个瞬时事件表示 ；并且定义了时间区间向量的概念和在它之上的一些运算 .