Interactive Digital Media Services Platform-Design And Realization Of Vod System

Video On Demand(VOD) is an information service technology launched recently which is a new way to combine the multimedia technology and network technology. For this thesis, the ultimate goal is to build a VOD system with the target of large, high performance, high practicality, extensibility and balanced load. In the process of particular construction, we use distributed architecture and normal personal computer(PC), which can make an efficient and practical video service platform available to more and more users. Overall, the study task mainly includes designs an efficient load balanced algorithm, build a large LVS cluster system for the video service, and the specific designs of the system structure and so on.We have completed the design of the VOD system and tested it in Chongqing wired network for detecting the numbers of users it can hold and the requirements of the network about the VOD system, as a basis for the analyze of the feasibility of this system. After the overall analysis of the whole system, the system can be divided into four subsystem including a program form subsystem, an information feedback subsystem, a dispatching subsystem and a database subsystem, thus formed a three-tier system model which contains a VOD management server of the center computer room, a sub-server for content demand, and set-top boxes terminal for users demand. Making the system flow chart of the data transmission among the VOD management server, the sub-server, and the user set-top boxes designed at the same time, as well as achieving the RTSP protocol to complete the transmission of media data from the sub-server to client terminal. Finally, built a simple environment and test the system.This thesis is focused on the study of VOD video server, proved select the distributed type VOD video server not only can run freely in the LAN, the most important is that it has a certain extensibility, which can extend the server system to the system can be in the range of large-scale telecom applications through practice, and it is very great prospect.