摘要： 介绍了MPEG-4标准中的二进制格式的场景描述，基于XML的两种可扩展文本格式的描述框架：XMT-A和XMT-Ω及其支持的节点、属性、域与BIFS流的映射关系；给出了MPEG-4标准场景视频制作及发布系统的功能结构和基于XMT的系统层次分析。利用该系统制作和发布的多媒体交互式场景视频，可以进行网上教学的节目制作和远程点播。系统建立在MPEG-4标准上，提高了远程教学的质量，满足了用户与场景视频的交互需求；利用XMT作为中间描述格式，满足了相同场景在MPEG-4、SMIL、VRML等标准间的内容交换及互操作功能。

关键词: MPEG¬, -4, 可扩展标识语言, 场景视频, 流媒体

Abstract: This paper introduces the scene description of binary format in MPEG-4 standards and two extensible textual format of XML: XMT- A format, XMT- Ω format; the mapping between BIFS and their nodes, attributes and fields. It also gives the function structure of MPEG-4 scene video manufacture and release system and the system layer analysis based on XMT. The interactive multimedia scene video which makes use of the system can manufacture the program for Internet teaching and play video on demand of long range. The system established on MPEG-4 standards raises the quantity of the long range teaching, satisfies the interactive necessary of user and scene video. XMT which is a central descriptal format allows the content exchange and interoperability between MPEG-4, SMIL and VRML standards.

Key words: MPEG¬, -4, XMT, Scene video, Streaming