The Research Of Transmission Technology In Live Streaming System

With the development of the Internet, streaming transmission by network has become a hot spot. Moreover, in the field of mobile Internet ,it has also been widely used. At present, most websites of stream media in our country still adopt the approach of centralized service, just putting the server focus detached in one data center to offer unified service and management for the nation, even the whole world. The advantage of this approach is the simple structure and easy management. However , with the increase of users, the rapid development of broadband access and the sharp growing of request, it is bound to bring tremendous pressure to streaming media servers and the bandwidth of website, which has negative influence on service quality. At the same time, network multimedia with low resolution and low frame rate does not meet the needs of business and life any longer. Therefore, it if of great importance to design a good network service mode and reasonable content deployment strategy to achieve the distribution of live streaming media and to find a efficient codec technology and transmission control strategy to speed up streaming media transmission.This paper describes the current situation of streaming media technology in live streaming system , the network protocols in live streaming system and other key technologies. In addition, compares P2P and CDN technology advantages and disadvantages, proposes a novel network construction which is a model of video transmission combined the concept of CDN. This model avoids the bottleneck which may affect the data transmission speed and the stability, solves the network congestion, makes the content delivery faster and more stable as much as possible. CDN system is able to redirect users'request to the nearest server to achieve the purpose of streaming media acceleration according to the comprehensive information including the flow of network ,connections between nodes, load conditions ,the distance to users and response time. Moreover, this paper does research on the streaming media transmission standard, focuses on H.264 codec standard in order to get better service quality with lower coding rate, designs appropriate network transport and control solutions, does network adaptive on server side, which help to achieve the purpose of the acceleration of streaming media transmission.Based on the established model, this paper elaborates the overall design concept, introduces functions and features at all dimensions of the module entities ,analyzes existing potential problems and proposes improvement program, depicts the operation of the process in detail, optimizes the delivery using H.264 and the problem of complex installation on client side, implements the basic functions of sending live request to the delivery networks, push the media to the steam server in edge, and finally show to user in browsers, by using java multimedia develop framework JMF to program, communicating with Socket for each layer. After system implementation, the author built testing environment, did testing to live streaming system. The result shows that it has achieved the purpose concerning stability, image clarity and system operation.