Monitoring technology from last centuries 80 time enter since our country, with the security of the sharp increase in demand has been in rapid development. From a technical point of view, Wireless keyboard has gone through many different stages of development. In 2000 China's first domestic DVR came out, began to enter the China security industry. Subsequently, in the technology and market of double drive, DVR began to make a spurt of progress of development. By 2006, the DVR has occupied the whole of video surveillance for nearly 40% of the market share. In the video monitoring from analog to digital development process, DVR plays a very important role, can be said that, DVR has a digital control era. But in monitoring market network demand, known as DVR replacement -- NVR concept was frequently mentioned.


NVR called NetworkVIDEoRecorder, compared with DVR ( DigitalVIDEoRecorder ), its core advantage is mainly reflected in the network. The DVR system, the center deployed DVR, the deployment of monitoring point video equipment ( analog camera ), audio equipment ( pickup / microphone ) and alarm equipment ( heat / smoke ), various monitoring equipment with the center point DVR respectively by video, audio, control, alarm cable one one. DVR provides focused coding, video and control signal playback. The NVR system, the center deployed NVR, the deployment of monitoring point network camera or video adapter, monitoring equipment with the center point between the NVR any connected to an IP network. Video, audio monitoring and alarm signal through the network camera or video adapter after digital processing, IP stream form to upload to NVR, from NVR centralized video storage and management. The combination of network cameras, video encoder and IP front-end, NVR can provide a full IP video monitoring solution, Google TV remote the user only needs to use the existing network to complete the system of rapid deployment, and may at any time, any place for any targets in real-time monitoring and management. Based on the full network processing, NVR in deployment, application and management of all aspects to provide a new, innovative solutions, has hitherto unknown network advantage.

Demand analysis

Video monitoring system of storage devices to the application characteristics of video monitoring system in general has the monitoring points, the number of monitoring camera, long time, data acquisition time is often a few days. Video monitoring system based on storage device in a data reading and writing mode with other types of systems with different characteristics.

Characteristic:

The digital video encoder or the video server to stream the data written to the storage device, real-time monitoring point back to image and picture in the streaming media mode is stored in storage, playback workstation in the streaming media mode to read the stored video file. The read and write mode with the common database system or file server system storage using small data blocks or grade reading and writing a completely different way, so the video monitoring system is stored in the technical parameter requirements and other application system has bigger difference.

Characteristics of two:

Large video monitor system often have 1000-2000, even more surveillance cameras, each camera generally use the D1 format back image. Each D1 image code rate of 2Mb/s camera, all accumulated super to required a total of 200-380MB/S of bandwidth. Video capture process, video file formats are generally not changed, and the rate constant, Android TV remote video frame rate of image in 15-25 generally frame between /S, that is stored in the read and write operations, must ensure that every 1/25 seconds can reach 200-380MB/S bandwidth, otherwise the image acquisition or playback frame dropping phenomenon will appear storage device itself, unless a large capacity cache configuration. The video monitoring system storage requires not only the large bandwidth, also called the bandwidth is constant.

Characteristics of three:

Data read and write operation of long duration. As the camera is generally 7*24 hours of work, even if the streaming media file using a segmented storage mode, online ups power the write operation duration may also have up to 2-6 hours later playback, also have the same time. Therefore the requirement for storage with super long time working ability, keep long time stability.