Monitor video server role

Video server plays a role in monitoring

What is network video surveillance? Network video surveillance is relative to analog surveillance and digital surveillance. In analog surveillance systems, image transmission, exchange, and storage are based on analog signal processing techniques. Digital monitoring introduces advanced digital signal processing technology and realizes digital storage represented by DVR. The network monitoring is based on digital signal processing, which realizes signal transmission, exchange, control, video storage and on-demand playback in a networked manner, and realizes all codec devices in the system by setting up a powerful central management platform (CMS). And unified management and centralized control of video storage devices. For the user, only need to log in to the central management platform to realize unified calling, browsing and management of the monitoring resources of the entire network. Network video surveillance implements end-to-end networking. The system architecture consists of IP front-end, TCP/IP network, central management platform, network storage device, TV wall decoder and client.

The video server can be divided into two categories: video encoder and video decoder. The video encoder is located at the front end of the network video surveillance system, while the video decoder is located at the user access end (or back end).

Video encoders are used to digitally compress and network front-end signals (video, audio, and other signals), including monitoring point analog video and audio information and access to alarm information, encoding/compression, transmission, and peripherals (such as cameras, Control of cloud mirrors, matrices, etc.). The above information is processed by the video encoder and uploaded to the central management platform through the IP network, and then distributed to the client, the video decoder, and the video storage device by the central management platform.

The biggest difference between video encoders and network cameras is that the video encoder's video source comes from analog cameras and needs to be used with analog cameras. The network cameras are integrated and integrate analog video capture. From the current situation, although network cameras are emerging in large numbers, video encoders will still occupy an irreplaceable important position in network video surveillance systems for the following two reasons: First, a large number of established analog and digital monitoring systems In order to protect the investment of existing analog cameras, these transformations will generate huge video encoder deployment requirements. Second, the selection of network cameras is far from being large, and it is difficult to meet the application of different users. Demand, so many applications must be based on the analog camera plus video encoder mode to achieve digital networking of the front end.

The video decoder is used to receive the network video monitoring code stream forwarded by the platform under the control of the PC client, and decode and output the analog signal to peripheral devices such as a video wall and an audio, and is usually deployed in the monitoring center of the user. The video decoder differs from the PC client in that the video decoder is generally based on hardware decoding, displaying the surveillance image through a dedicated display device, and the PC client directly displays the surveillance image through the PC display. Because PC clients have more control and management functions, and access is flexible and operational, applications based on PC clients for monitoring and browsing are becoming more and more popular. However, because the video decoder is based on hardware, the performance is stable and the image quality is good, so it is very common for many applications that need to centrally decode the upper wall.

Video server purchase points

Video server purchase points

In the face of a dazzling array of video servers, here we mainly choose the right video server products according to the functional requirements.

1. Whether the product has relevant qualifications. Although the product qualification does not fully represent the quality and performance of the product, it is the basic condition for the acceptance of many system integration projects, and it is also the basic condition for the product to be qualified.

2. Deliver the actual bandwidth requirements of standard real-time moving images. This is one of the important indicators to measure the overall performance of a network video server. High bandwidth means an increase in the cost of network usage. For end users, this will shake their determination to adopt a digital surveillance model. After all, economics is a problem that any business unit has to consider.

3. Delay in remote video transmission. Although the transmission delay is inevitable for any kind of network video server, the delay values ​​of different network video servers are different. The delay value will directly affect the effect of digital monitoring. Imagine that when the monitor controls the front camera pan/tilt through the mouse in the monitoring center, he clicks the mouse five times in five seconds, and after tenth seconds, he sees the pan/tilt after the first click on the display. Control effect, what will happen?

4.IE monitoring function. Conventional monitoring and management software is used to achieve the integrity of the function, the operation is cumbersome and inconvenient, and even requires special training and learning to be proficient. The management software provides a simple WEB version of the monitoring management software selection suitable for leading or non-professional monitoring managers. It can provide single screen image monitoring, recording, control and other functions in the form of IE webpage. Users do not need to install professional software. When monitoring image selection, there is no need to memorize the complex IP address of different network video servers. Just access the system's WEB server to download the configuration information control such as the preset monitoring point name. The mouse click to select the relevant image name to realize the monitoring function.

5. Image compression algorithm standard. The current mainstream network video server compression algorithm standards are nothing more than MJPEG, MPEG-1, MPEG-4.

6. The number of video channels that the monitoring center can monitor and record at the same time. Since the network video monitoring server is mostly used for remote, real-time and centralized monitoring of multiple distributed network points, the number of video channels that the monitoring center can simultaneously monitor and record is an important indicator for measuring the effect of remote centralized monitoring.

In theory, remote real-time monitoring and recording can be performed on an unlimited number of monitoring target images at the same time. However, in actual applications, the actual network bandwidth of the monitoring center is limited. For example, if the central network bandwidth is 10M, assuming that each video occupies 250K, a maximum of 40 video recordings can be achieved unless the video bandwidth is increased or the network bandwidth is increased.

7. Warranty issues. The quality assurance issue is one of the most concerned issues for engineering companies. As the engineering company directly faces the end user, the unsatisfactory after-sales warranty service will directly affect the reputation of the contractor.