Directshow-based Network Video Monitoring System

Public safety and people's lives are inseparable,as part of security system,the video surveillance system is very important for industrial production,people's lives and social security.In recent years, network video monitoring system has become a hot spot in the field of montoring application.However, the current IP networks provide only best effort service, does not provide any Quality of Service (QoS) guarantee.To ensure real-time video transmission of QoS, needs to adopt new technologies and methods.Use of the existing network conditions, providing a good video quality, network-oriented real-time transmission of video surveillance systems need to solve the technical difficulties.This paper presents a DirectShow-based network video monitoring system design and implementarion,it uses multi-threaded structure of H.264 video encoder,propose a drop frame coding algorithm based on motion detection,improve vedio encoding quality, increase compression ration,achieving an effective rate control.Through TCP, UDP protocols for in-depth analysis,combined with real-time transfer protocol RTP,proposed a real-time transport protocol named EVS,and focused on real-time video transmission of the control method,effectively improve the smoothness of the video stream to reduce the delay,jitter, packet loss rate and increased network bandwidth utilization,In order to achieve real-time video transmission QoS.Monitoring system using client/server two-tier distributed architecture model, with good reliability, portability, and maintainability.Front-end server, responsible for collecting surveillance video and audio, compression encoded, packaged into RTP packets,application of effective transmission control strategy,transfer the media to monitoring center in the from of streaming media; Monitoring center,receive video and audio data from each front-end server through the network, a buffer by a certain mechanism to ensure the continuity of media data, according to encoded formats, frame rate information of each server to decode the original video and audio data, respectively, displayed in different area and play, to the effect of multi-screen monitor.At the same time according to need to store surveillance video, audio, storage format for the ASF file format.This article is designed for network video monitoring system has been successfully run on the LAN, the WAN,and has certain practical and promotional value.