毕业设计耿文宾.doc

可视化专家在线咨询系统的研建 摘 要 农村教育的普及以及农民知识文化水平的提高增强了农民科技务农的意识，同时他们对科技务农的需求也变得空前高涨。然而农民在务农过程中遇到了各式各样的技术难题，为了解决农民的这些技术难题，采用目前快速发展的计算机技术、网络技术，特别是流媒体技术，开发能够使农户与农业专家进行可视化在线咨询的系统，实时的为农户服务。 本系统采用了实时流媒体技术的优秀平台JMF技术开发，JMF集成了Java处理多媒体的API函数，能轻松地实现流媒体的采集、传输、管理；另外，本系统还采用Java-Socket通信机制，通过几项技术的结合，完成了专家在线咨询系统的开发，实现了农业专家与农户的可视化交互。 关键词：可视化；在线咨询；JMF；Socket The built of on-line visualized expert consultation system Abstract With the spread of education in rural areasand the increasing level of farmers knowledge, farmers enchance their awareness of science and technology in agriculture day by day, at the same time, the demand for agricultural science and technology is becoming unprecedentedly high. In order to settle the difficulties farmers encounter in using current rapid development of computer technology, it is necessary to adopt the rapid development of computer technology, net technology, especially streaming media technology to develop an on-line visualized consultation system, which can help farmers inquiry agricultural expert by visualization and provide real-time service for farmers. The system used JMF technology development tool, which integrate the multimedia processing Java API and is an excellent platform of real-time streaming media technology. It can realize the collection, transmission and management of the streaming media easily. Moreover, the system also used commucation mechanism Java-Socket. With the combination of several techniques, it not only complete the development of online system, but also realize visualization interactive inquiry between agricultural experts and farmers. Key words：Visualization;Online Consultation;JMF;Socket1引言 1 1.1项目研究意义 1 1.2项目研究现状 1 1.3项目研究内容 2 2流媒体技术 3 2.1 流媒体技术简介 3 2.2 TCP协议实时数据的传输性 3 2.3 RTP协议 4 2.3.1实时传输协议RTP 4 2.3.2 RTP架构 4 2.3.3 RTP协议的报文格式 5 2.3.4 RTP在协议层中所处的位置 6 2.4实时传输控制协议RTCP 6 2.4.1 RTCP协议 6 2.4.2 RTCP发送方报告(SR)数据包的格式 7 2.4.3 RTCP的控制功能 8 2.4.4 RTP的特性 9 2.4.5 RTP/RTCP协议保证多媒体信息实时传输 9 3系统设计技术 11 3.1 JMF简介 11 3.2JMF系统介绍 11 3.2.1JMF体系结构简介