The Research Of Embedded Video Server Based On AVS_M And Proxy Cache Technology

With the development of the technology of multi-media,video compression and network communications,the embeded video server techmology has become a research hot spot in the field of video applications today,having a wide range of applications in the field of monitoring and other video services.There is no denying that the current embedded video server is very powerful with exception of many drawbacks to impeded the promotion of servers.And most of the mainstream video servers adopt the H.264 and MPEG encoding standards,with which the Royalties alone is up to billions of dollars every year.the price of the server is far beyond what it actually is worth,which has been preventing the technology from popularization across the country.Technology monopoly makes our businesses development difficult in this area.In order to avoid this phenomenon,probe into AVS_M coding standard's applications in the ARM+Linux environment.studing the key technology of the embedded video server based on AVS_M is very necessary,and in order to further improve the quality of service,the proxy cache technology that play a critical role throughout the system is discussed in the article.Some pivotal technologies of the video service system are analysised particularly in the paper.AVS_M coding technology,streaming media transmission technology and the proxy cache technology are included;the AVSM coding technology includes transform and quantization,intra predection,motion estimation and entropy coding and so on;streaming media transfer protocol includs RTP/RTCP/RTSP;and the proxy cache technology involves the prefix cache,the adaptive segment cache,the popular segment cache and the modification of popular segment cache technology.The main tasks of the paper include:achieve video capture and encoding functions based on linux operation system and PXA255 hardware platform, researching and analyzing the process of realization of AVS_M coding;Achieving the AVSM video streaming transmission in the network and bringing up AVSM transmission and package formats on the basis of analysis of RTP,RTCP,RTSP and other related protocal;and then,for further improving the quality of video services and incressing the hit rate and reducing the jitter and delay,a more efficient proxy cache algorithm-the modification of popular segment proxy cache is made after studing some other algorithm.this method can inprove the cache utilization rate and hit rate by correcting the popular segments and making the popular segments and no-popular segments separate.In the end,the paper gives and analyses the validity of the policy and the essentiality of using the proxy cache technology.