The Research And Implementation Of Interactive Multimedia Real-time Teaching System Base On IP Network

Multimedia real-time teaching system refers to computer aided teaching system which carries on teaching with the aid of modernized multimedia technology in the computer network environment. Network multimedia teaching system allows students in different space and time to share study resources ,and it also allows them to discuss and study together through coordination dialogue. Compared with the traditional teac- hing way, the multimedia network teaching has the incomparable superiority.This paper proposes and constructs an interactive multimedia real-time teaching system base on IP network. This system uses the Client/Server construction, and it is divided into two parts,the teaching end and the listening end. The system portal frame construction is divided into four layers,they are surface layer,system manage layer, media interactive layer and data processing layer.Surface layer defines the view of the contact surface,system mange layer controls the movement process and the data flow of the system,media interactive layerl contains all kinds of media datas,and offers datas to the data processing layer to process.According to the function,the entire system is divided into seven modules,they are system manage,audio and video data processing,screen recording, electronic tabula rasa, teachers and students interaction,stream media transmission and UDP group broadcasting transmission.This system uses DirectShow development technology to realize the collection, compression and playing back of multichannel stream data;it uses RTP/RTCP protocol to realize the high quality and hign efficiency transmission of stream data;it realizes multi-patterns interactive methods including characters,voice and electronic tabula rasa between teachers and students,and proposes a new method to realize the electronic tabula rasa in real-time teaching system on the basis of the research of the digital ink technology.This paper studies the essential technology in real-time teaching system,and by combining the stream media synchronization model,studies the synchronous strategy of audio and video from letter source,network transmission and letter destination these three aspects in the audio and video transmission process. In view of the network model of this system,this paper proposes the corresponding transmission strategy of stream media, the splitting and combining packets arithmetic and the cache dynamic allocation strategy in RTP network transmission by analyzing the impact of UDP packets size on the data transmission.This real-time teaching system connects teachers and students in different areas in real time,it is able to realize the live broadcast of the teaching process and multi-patterns interactive methods between teachers and students,it also shows some merits,such as low cost,flexibility,reliability and efficient,it can meet the basic requirements of real-time teaching.