The World Wide Web has become a new and powerful medium. However, applications on the Web are currently not fully multimedia supported. This is mainly because that the synchronization in the Web environment can be extremely complex, as the network infrastructure on which the Web is based provides no guarantee of real time data transfer, especially for large media, such as audio and video. In this article, weak synchronization is introduced as an efficient approach to specify temporal relationships among objects in a multimedia document to gain the best presentation performance. This approach provides a new modeling mechanism that can specify the precise as well as imprecise temporal relationships among involved objects. Specifications on inter-media synchronization, such as strict synchronization method and loose synchronization method, are also included in the approach.%在当今世界,WWW已经成为新颖而强大的媒体,但是,现在运行于Web上的应用仍然不是完全多媒体化的.这主要是因为Internet网络是不可靠、尽力型的,无法提供数据实时传输的保证,尤其对那些大数据量的连续媒体(如视频与音频数据).因此,在Web环境中多媒体对象间的同步就变得格外复杂.该文提出了一种新颖的同步模型:弱同步.它使多媒体文档即使在多变的环境下也能获得最佳效果.在弱同步中,不仅可以定义对象间确定的时间关系,也可以定义非确定的时间关系.此外,媒体间的同步关系,如严格同步和松散同步,也可以在文档的同步描述中定义.
展开▼
