Design And Implementation On Network Multimedia Teaching System

With the successive development of global information society, it is necessary that education use more information technology. The network multimedia teaching is gradually becoming the mainstream of education form that develops the teaching space and time latitude. The network multimedia teaching provides learner with rich resources of high quality, it will certainly have the positive influence on improving the teaching quality, transforming the teaching methods and promoting social education.In order to meet the demand of teaching and management of computer laboratory, I design and implement a network multimedia teaching system. In the aspect of screen image capturing, this system uses the newest technology of DX9, and solves the problem that exists in commercial network teaching system in which the surface of video player can not be captured, and enhances the screen capturing and rendering speed. In the aspect of multimedia data compression, this system selects different compression methods for the different media information. For the screen image information, we find the changed area first, then compress and transfer the data of changed area. For the mouse, we separate it from the screen image and transfer it with a mixed method that includes semantic compress and image compress, thus its movement has the continuity. UDP protocol with multicast broadcast technology is used for data transmission. I design and implement the transmission controlling protocol on application layer that enables the media data to be reappeared correctly and synchronously on the client side. UDP protocol is also used for the transmission of control commands and files. Through the protocol of application layer, files are transmitted efficiently to the student side with the UDP protocol. In the other aspects of aided teaching, we provide practical functions such as remote controlling, computer information, screen video recording and so on.The study of this paper makes the network multimedia teaching system become more effective for capturing screen, higher speed for compressing, shorter time on postpone and more stable.