Design And Implementation Of HD Video Monitoring System For 4G Mobile Network Based On Android

Today's mobile video monitoring system transmits HD video that is generally 720 P,bit rate of 512 Kbps or so.Higher bit rate HD real-time video,with the image quality doubling,puts forward higher requirements for the system:increasing hardware processing speed,increasing network bandwidth,efficient design of software systems and improving network transport protocol.In this paper,HD video transmission system of 4G mobile network is realized by the efficient design of software system and the optimization of network transmission protocol,and HD video(1080P)transmission with high bit rate(1024Kbps)is realized too.This paper analyzes the key technology of HD video surveillance system of 4G mobile network,and puts forward the implementation of video obtain forwarding equipment software and Android surveillance user-end software.In the video obtain forwarding software,system synchronizes the receive thread and send thread through the semaphore.Circular queue buffer technology is applied to smooth video forwarding caused by the impact of network fluctuations.In the Android monitoring user-end software,using multi-threaded video decoding playback improves the efficiency of the software.Also achieving the capturing,recording and clarity selection and other common functions diversifies the system function.For the video jitter and Huaping caused by network problems,this paper presents the reciver RTP processing mechanism to optimize the video performance of the Android monitoring client,smoothing video stream jitter through the ring queue,and filtering the incomplete video frame through verifying the integrity of a frame RTP packer.4G mobile network HD video monitoring system mainly uses 4G wireless network for video transmission.Because of the low efficiency of TCP transmission in wireless networks,UDP packet loss and other issues,paper adopts UDT protocol to transfer data.Because network congestion detection algorithm of UDT protocol can not differentiate congestion data loss and wireless wrong data loss.Miscarriage of justice for network congestion can happen in the high bit error rate of 4G wireless network.This paper proposes a network congestion decision strategy based onRTT(round trip delay).The network congestion is classified by RTT,and network congestion is determined by combining network packet loss and network congestion level.And achieving the algorithm in UDT protocol gets UDT_BR protocol.This paper tests UDT_BR throughput in actual 4G internetworks and wifi network combined with TCP and UDT protocols.The experimental results shows that the UDT_BR protocol has a certain improvement in transmission efficiency comparing with TCP and UDT protocol.After the successful implementation of the whole system software,this paper tests the system in 4G internetworks and wifi network.Test results show that 4G mobile network HD video monitoring system is stable and practical,transfers clear video,ables to transmit 1080 P HD video of 1024 Kbps rate.