The video surveillance system has several parts and functions

What are the functions of each part of the video security monitoring system?

In terms of realized functions, a complete video security monitoring system usually consists of five main parts: front-end acquisition, signal transmission, control, display and storage.

Front-end collection

The front-end acquisition part completes the acquisition of the video signal. It includes one or more cameras and matching lenses, PTZ, protective cover, PTZ decoder, infrared light, voice collection and other equipment to complete the collection of image information, voice information, alarm information and status information. The camera uses the built-in CCD and auxiliary circuit to photograph the scene situation into an analog/digital video signal, which is transmitted to the monitoring system. The motorized zoom lens can zoom in and out of the shooting scene, and realize optical adjustments such as aperture and focus. The pan-tilt and protective cover provide a suitable working environment for the camera and lens, and can realize the horizontal and vertical adjustment of the shooting angle. Decoder is the core equipment of pan/tilt and lens control, through which it can realize the use of microcomputer interface to control the lens and pan/tilt through software.

Signal transmission

The signal transmission part completes the transmission of front-end audio and video, control and status signals. According to the type of transmission signal, it can be divided into two categories: digital and analog. Commonly used analog transmission media include line types such as coaxial cable, analog optical fiber, and microwave; digital transmission systems mainly include the well-known TCP/IP network, and line types include twisted pair, optical fiber, and wireless networks. Regardless of whether it is a digital or analog transmission system, its cost, transmission distance, and transmission capacity are different. In practical applications, flexible selection and combination should be made according to their respective characteristics.

control

The control completes the display switching of audio and video signals, PTZ control (PTZ), and resource allocation, which is the core of the video security monitoring system. It includes audio and video signal switching and distribution, cloud mirror control, operating keyboard, various control communication interface conversion and other equipment; it also includes supporting power supplies, consoles, monitors and other equipment. In a digital system, control has risen to a broader level. In addition to display switching and cloud mirror control, it also includes equipment management, authority management, code stream scheduling, bandwidth control, area management, network management control, etc. This is a monitoring technology and The product of the combination of IT technology. With the introduction of these new control methods, the surveillance system has become more than just a tool for recording and playback, it has become a management method that can cover a wide area.

show

The display part completes the output of the video signal terminal equipment. There are many types of video image display equipment, from traditional monitors, LCD monitors, projectors, to today's DLP, LCD splicing screens and other equipment. The display of video signals is divided into two types: digital and analog. There are two types of digital display: one is the YUV digital signal preview display, which is usually used in the preview display of digital hard disk video recorders; the other is the decompression and restoration display of compressed digital signals, which is usually used in digital hard disk video recorders or networks. Video playback and remote viewing of the hard disk video recorder.

Video storage

The video storage part mainly completes the storage and playback of digital video signals. Its main goal is to ensure the integrity and safety of the storage period and data under the premise of ensuring the quality of the playback image. According to the different solutions of the video security monitoring system, the storage composition scheme is also different, usually mainly composed of hard disk video recorder (DVR), network hard disk video recorder (NVR), network storage and other equipment. DVR/NVR is mainly used in small systems; network storage is mainly used in large and medium-sized systems.