Adaptive Rate Video Transmission Based On The Gprs Network

After the description of the characteristics of GPRS network and the video transmission protocols,the video transmission rate adaptive algorithms based on the UDP for GPRS network were proposed.The algorithms,including the choice of the first video algorithm,packet loss rate prediction algorithm,as well as video rate adaptive adjustment algorithm.Algorithm simulation results show the choice of the first video algorithm can effectively reduce the times of video switching.Packet loss rate prediction algorithm,in terms of stable network environment or dramatic changes in the network environment,can more accurately predict the packet loss of the next time.Video rate adaptive adjustment algorithm can effectively reduce the times of video switching,and enable the rate convergence as soon as possible.In the choice of the first video algorithm and video rate adaptive adjustment algorithm,the user preference,the value of "like",was added,so that the appropriate fine-tuning of the rate adaptive adjustment algorithm can be made in accordance with the user preference on screen quality and fluency.Finally,the description of the rate adaptive transmission system is made. The system is based on video server "Darwin Streaming Server(DSS)" and mobile phone-player "Bell Player".DSS is open-source software.Bell Player migrates the Mpeg4 IP projects,which is open-source software and was originally run in the Linux kernel,to Windows CE core.According to the need for adaptive algorithms,the two open-source software code was amended.So that a solution,which involves PDP context activation,NAT penetration,heart rate data packets,video on demand and document switch,is achieved in the GPRS network.