【作者】 胡军；

【导师】 侯整风；

【作者基本信息】 合肥工业大学 ， 计算机应用技术， 2002， 硕士

【摘要】 本文首先综述了网络远程教学的现状和发展趋势，分析了基于Web的远程教学系统的缺陷，探讨了流媒体同步等问题，在此基础上设计并实现一个远程实时教学系统，使教师和学生间实时地在线交流，达到面对面的即时效果。 本系统具有以下特点： 所有信息数据的传送都在传输层实现，与在应用层实现相比，不仅减少了协议层之间流动的时间开销，而且提高了有效数据的传输速率，有利于实时播放多媒体影音文件。 直接使用UDP传送流媒体文件，流媒体数据传送采用服务器集中处理同步方案，客户端采用双缓存机制进行流媒体的接收和播放缓冲，并使用DirectShow播放流媒体，进一步减少了流媒体的传输和播放延时。 为了减少数据处理延时，在套接字的选用上，没有使用系统提供的套接字封装，而是直接使用了Socket API函数，建立了套接字的消息传递机制，并利用结构和指针列表进行套接字的动态分配，使服务器对于客户端的连接数量不受任何限制。更多还原

【Abstract】 This thesis generally demonstrates the present and trend of Network Remote Teaching, and analyzes Streaming Media synchronization, and shortages of Remote Teaching based on Web. Above all information, we design and realize the Remote Real-Time Teaching Software system. Teachers and students achieve real-time intercommunication if face to face.The software system has such characteristics as follow:All the information including Streaming Media are transported in transport-layer. Its speed is much higher than in application-layer because it cuts down the time in data processing between two layers and can transport more pure data in equal time.Streaming Medias are transported directly in UDP packets. We select the synchronization of Server-Centric Model. Received data are put in two blocks of memory, and these are considered as saving pool and playing pool. Playing Streaming Media use DirectShow.In order to reduce the time of processing data, we directly use the function of Socket API, and set up a set of message map. It is countless that clients connect to server, and this is realized by using structure and pointer.更多还原