Design And Implementation Of Real-time Video Transmission Scheme Based On KCP

With the continuous change of wireless communication technology and the continuous improvement of Android intelligent mobile terminal performance,the terminal equipment in video transmission system is migrating from personal computer and fixed camera to Android intelligent mobile terminal.At present,most of the video transmission systems in the market need high bandwidth support to ensure the real-time of video transmission.When encountering the situation of network congestion,these video transmission systems can not guarantee the real-time of live video or even interrupt the live video,which is an abnormal experience for users.Based on the above problems,this thesis provides a real-time video transmission scheme based on KCP protocol.Aiming at the problem of poor real-time live broadcast in the extreme of network congestion,we try to use KCP protocol as the video transmission protocol on the protocol side.In this scheme,Android smartphone is used as the streaming and playing end of real-time video transmission system,and KCP protocol is used for end-to-end communication.As a reliable ARQ protocol,KCP protocol is designed to deal with the problem that TCP network communication speed is very slow in the case of network congestion.In this thesis,KCP protocol is used as the video transmission protocol between Android streaming terminal and Android player,which can effectively guarantee the real-time performance of the live broadcast system in the case of network congestion.In addition,this thesis also adds frame tracking calculation to Android player to ensure the real-time performance of live broadcast when the network jitters.The main work of this thesis is as follows:1.In order to realize the Android Streaming Terminal Based on KCP,this thesis uses KCP client as the Android streaming terminal,and designs and implements each module in the process of video data collection and transmission in the Android streaming terminal.These modules include real-time video data collection,copy,preview,modification,coding and transmission.2.In order to realize the Android player based on KCP,this thesis uses KCP server as the Android player,designs and implements the modules in the process of receiving,decoding and playing real-time video data from video data in Android player.3.In order to reduce the accumulated delay of Android player when the network jitters,this paper designs a frame chasing calculation to determine whether to discard the packets according to the video data timestamp at the end of the queue by traversing the KCP packet receiving queue.In order to verify the effectiveness of the system,this thesis tests the function and performance of the real-time video transmission system,verifies the correctness of each module in function and the real-time performance of real-time video playback,which can meet the requirements of actual use.