Research And Realization Of The Video Education System Based On Streaming Media Technology

With the rapid development of science and technology,distance education plays a more and more irreplaceable role in modern education.Through the omnipresent modern network,distance education goes beyond space and time,constitutes the educational system of lifelong learning and produces tremendous social profits.In the network video learning system,synchronous live broadcast is an important part.Traditional method of live broadcast always uses closed-circuit TV system or satellite transmission.It gathers information of teaching by video/audio gathering equipments and transmits processed data to student.This method's cost is enormous.With the development of streaming media technology,researchers bring it into the field of video learning,which processes real-time data and transmits it by the network.This alternative saves cost and time.Many video learning system based on streaming media technology adopt the C/S model,but as the number of clients is increasing,the access to servers is too large, which bring about the burden of servers is heavy and the decline of the quality of servers,which ultimately affect the effect of learning.With the development of P2P network,researchers find the P2P multicast need not certain servers,and saves many hardware and management cost.Therefore,using the P2P technology to resolve the problem of bottleneck in network video learning becomes a new question focused by many researchers at home and abroad.This paper introduces the technology of streaming media and researches the P2P network deeply,then put forward an optional video learning system based on streaming media,which integrated the C/S model with P2P model.The system is developed using VC program language.It uses the filter framework of DXSDK to realize the live gathering of video/audio,and develops streaming filter by means of Windows Media streaming technology.The gathered data is compressed to the format of DXSDK.In the C/S model,data is distributed to clients by the components of Windows Media,whereas in the P2P model,the tree pattern of single resource is used to transmit data.The transmitter and receiver form a multicast tree.The middle node receives the data of its father node and meanwhile transmits it to its son nodes. Besides,the system develops other accessorial functions,such as on-line message communication,virtual member list and so on.The functions can sustain the message communication between teachers and students,and achieve the management of members.The paper realizes an integrated video learning system contains video gathering, streaming,distributing and watching.This system is developed and tested,then set up in the LAN of related maritime unit.The distribution of video integrated the features of C/S and P2P models.The clients can choose the models according to the factual situation.Under the circumstance of small number of clients,they can choose the C/S model,whereas if the number of clients increases,they can choose the P2P model. This optional system gives full play to advantages of each model,and is flexible.