Study And Design Of High-Definition IP-Camera Monitoring System In WAN

With the development of network communication and video codec technology,there is an increasing demand for video surveillance used by individuals or in national urban constructions.Video monitoring systems utilizing high-definition internet protocol camera have become an important part of security field.To solve the problems of poor image quality,low compression rate,high bandwidth usage,and long delays in conventional systems,this paper focuses on video capturing,encoding,transmission,servers,and clients by combining the H.265/HEVC compression technology with TCP/IP network communication protocol.The contents are as follows:1.Research on Hisilicon media process platform.The paper studies the overall hardware structure of Hi3516A processor and key technologies of modules in media process platform.Modules contain the video capture module,the H.265 encoding module,and the region management module.After analyzing the characteristics of H.265 coding,and a novel transmission control method,which combines the linked list with video key frame,is proposed.The method can effectively improve the real-time performance of network video streams when the network speed is poor.2.Data processing and communication security.Transmissions between client and server have a variety of data packets,which have different data structures;therefore,the paper studies the JSON text interchange format,which is not only independent of language and platform but also can quickly parse and package network packets.To ensure data transmission security,the RC4 algorithm is used for encrypting the video streams.3.Construction of server architecture.The server acts as a relay station,which is the data exchange line Ibetween network nodes and viewing instruments.In other words,different data packets are sent to viewing instruments by the server.Therefore,the server should possess a high capacity of concurrent connection.Compared to traditional model,event-driven model based on Libev enables server to reduce the occupation of resources,enhance capability of reception services,and improve transmission efficiency of the network.4.Decoding and display of network video streams on viewing instruments.The video can be viewed in mobile phones and personal computers.To improve scalability and portability,the paper adopts the open-source librarys(FFmpeg2.2.16 and SDL2.0)for decoding and playing the H.265 network video streams.The device-side,server-side and viewing-side,three independent subsystems,are studied in this paper.The entire video surveillance system is tested in WAN.The results showed that H.265 bitstream can perform collecting,transmitting,decoding and displaying normally.Besides,it has great image quality,high video compression and small bandwidth usage.In addition,the sever has a good performance of high concurrent processing capability and low memory expense.Moreover,it has a short video delay.Especially,it will sacrifice image quality in order to improve the real-time performance and maintain a stable system when the network speed is poor.