Algorithm And Implementation Of Video On Demand

Network impels the spread of computers and at the same time computers become more and more impersonate. VOD becomes popular under the two strong trend. People can demand whatever movies he likes anytime any where rather than sitting in front of a TV for hours to watch a hot movies. VOD makes people again get control of their spare time. In nowaday society which so much emphasis personality VOD service will definitely has a wide foreground and immeasurable business value. However, many factors constrain the developing of VOD. Such as network bandwidth, the performance of VOD server, the strategy for video frequency sending, the strategy for program arrangement and so on.We can do many things to improve the performance of VOD system. Using high price servers or rebuilding a faster network do improve the system-wide performance. However, in reality, we have to consider the cost of a system, so we need to find a more economical way. Using better sending strategy or arrangement strategy which cost fewer really effects.Besides introducing some VOD concepts and some key techniques the paper focus on the following topics.First, sort VOD arithmetic into three main kinds: VOD server responding strategy, server arrangement strategy and flow sending strategy. On VOD server responding strategy side, the paper main introduce the concurrency responding and its key model. On server arrangement strategy side, this paper mainly introduces the Batching strategy and some real arrangement strategy based on Batching. On flow sending strategy side, the paper mainly introduce two main arithmetic: Broadcasting and Patching strategy. The paper also gives some contrast of these arithmetic.Second, when study the arithmetic of VOD I take part in a project named "the Study of remote education for cadres of Zhejiang Province" and in charge of the developing of the VOD module. In the paper I introduce design for NVOD and TVOD parts of the system.Third, introduce the specific implement of the module. The paper tell the relationship of all the sub-module, mainly involves the VOD key arithmetic and further more give out the improvement arithmetic. What's more , the implement of responding strategy and multi-thread scheduling also be presented.