【作者】 朱方胜；

【导师】 王舜燕；

【作者基本信息】 武汉理工大学 ， 计算机应用技术， 2006， 硕士

【摘要】 网络信息多元化发展,使音频、视频数据的实时交换成为WEB应用的必要组成部分。提供这种服务的关键点在于,如何在HTTP协议本身的无状态性以及WEB浏览器基于文本的信息处理方式等约束条件下,使音视频实时交互服务能与WEB元素无缝协作。 本文以现有的多媒体及网络技术为背景,阐述了一个基于COM技术、能与WEB页面元素平滑交互的音视频通用组件的设计方案。本通用组件运行于Win32环境下Internet Explorer浏览器中,可配置成在线直播(一对多)、远程监控(多对一)、视频会议(多对多)、视频聊天(一对一)等应用模型。组件各模块及其自身均为COM组件并遵循DirectShow框架。组件基于ATL开发,以Activex控件形式封装,嵌入WEB页面中通过属性与事件的方式与WEB脚本进行通讯;网络通讯协议以RTP/RTCP为主,音频数据压缩采用G.729标准,视频编解码部分采用遵循MPEG-4标准的XviD项目。组件可配以辅助服务程序来提高服务质量。辅助服务程序运行在不同操作系统上,使用标准HTTP协议与WEB应用模块通讯,进行客户身份认证及其他数据通讯业务。采用此组件的WEB应用中,音视频会话逻辑完全由WEB设计人员负责设计,组件与具体WEB应用开发环境无关。 文中首先介绍组件所涉及的几项关键技术,在此基础上提出系统的整体结构设计,并给出数据定义。论文主体介绍了组件各部分的详细实现方式,并给出各种应用模型及对应的测试数据,最后提出了完善此组件的方向与方法。更多还原

【Abstract】 The development of network information in different directions pushes it to be a necessary role that supplying real-time audio and video data exchange service for WEB applications. The key point of supporting this service is how to make it seamlessly corporated with WEB elements while the HTTP protocol is stateless and the main information for browser is based on text files.With the background of multi-media and network technologies, this paper presents a COM based audio and video communicating component which can work smoothly with the elements on WEB pages. The component runs in Internet Explorer browser on Win32 platform. It can be configured to operate at models of live broadcasting(one to many), remote monitoring(many to one), video conferencing(many to many) and video chating(one to one). Every module of the component is also a COM object which is built under DirectShow framework. The component is based on ATL and encapsulated as an ActiveX control which is embedded in WEB page and supplies properties and events for communication with WEB scripts. The protocol is designed using RTP/RTCP for data transmission and the XviD of MPEG-4 is used as codec. The sustaining server program can run on diferent platforms and uses standard HTTP protocol to communicate with WEB modules for client authenticating and information exchanging. When using this component, the control logic for session of audio and video exchange is totally handled by WEB developers. The component is independent to the environment in which the WEB application server is running.Firstly, several key technologies are introduced in this paper, then is the overall design of framework of this audio and video system and the data definitons. The main content of this paper is the description of how to implement such a component. Constructing every applicable model and the corresponding statistics is given after that. The ways of perfecting this component are represented in the end of this paper.更多还原