摘要
本文用一种以出现网为基网的时间Petri网作为多媒体系统模型。这种模型便于描述和分析并行媒体流间的同步问题。文中提出了时间层次同步和同步时间差阈值等概念。同步时间差同步是时间层次同步性能的一个度量。根据实现时间层次同步的可能性,一个时间Petri网中的同步变迁可划分为三种类型:理想同步变迁、可实现有效同步的变迁和不可能实现有效同步的变迁,一个好的多媒体系统的时间Petri网模型不应存在第三类同步变迁。文中给出了这三类变迁的判定条件。
A kind of time Petri nets are used to be models of multimedia systems in this paper. The underlying nets of this kind of time Petri nets arc occurrence nets. They are convenient to describe and analyze the synchronous problem between concurrent media streams. From the understanding of synchronization in multimedia systems, the concept of synchronization on time level and the concept of threshold of time distance for synchronization are presented. The threshold of time distance is a measure of synchronization on time level. The synchronous performance of synchronous transitions in a time Petri net model is divided to three classes according to the possibility of realizing the valid synchronization on time level and the decided conditions of this classification are given.
出处
《计算机科学》
CSCD
北大核心
2004年第2期11-16,共6页
Computer Science
基金
国家自然科学基金(60173053)
