Current situation and future development direction

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Current situation and future development direction of video surveillance system

video surveillance system is an important part of security system and a comprehensive system with strong prevention ability. Video surveillance is widely used in many occasions because of its intuitive, convenient and rich information content. In recent years, with the continuous development of modern science and technology, especially the rapid improvement of network bandwidth, computer processing capacity and storage capacity, as well as the emergence of various practical video information processing technologies, video surveillance technology has also made great progress. Video surveillance has entered the full digital network era, and has increasingly attracted people's attention and attention. The development of video surveillance system is basically the evolution process from the early analog closed-circuit television surveillance system to the digital analog video surveillance system and the current digital video surveillance system. According to the development of technology, the current digital video surveillance system is divided into three stages: the multimedia stage of digital surveillance, the DVR stage of digital surveillance and the network stage of digital surveillance

current situation of video monitoring system

1. Analog video monitoring system

analog video monitoring system is divided into two types: video switching control based on microprocessor and multimedia management of PC (5) obvious reform effect on the supply side and switching control of matrix host and multimedia management of the system based on PC. Analog closed-circuit television monitoring system is actually a combination of many analog monitoring equipment. The system is mainly composed of "front-end equipment", "terminal control equipment" and "signal transmission medium". Among them, front-end equipment mainly includes camera, PTZ, decoder, etc., and control equipment mainly includes switching matrix, picture splitter, monitor, control keyboard, video recorder, etc. Transmission media include cables, control lines, etc. With the enhancement and improvement of the function and performance of microprocessors and microcomputers, the application of multimedia technology, great changes have taken place in the function, performance, reliability, structural mode and other aspects of the system. The composition of the video monitoring system is more convenient and flexible, the interface with other technical systems tends to be standardized, and the human-computer interaction interface is more friendly. However, since the form of information flow in the video monitoring system has not changed, it is still an analog video signal, and the network structure of the system is mainly a single function, one-way, centralized information acquisition network. Therefore, although the system has developed to a high level, it has not much potential to tap, and its limitations still exist. To meet higher requirements, digitization is the only way. The main disadvantages of analog monitoring system are: A. It is usually only suitable for small-scale area monitoring. The transmission tool of analog video signal is mainly coaxial cable, and the distance of coaxial cable transmitting analog video signal is not more than 1km, and the distance of twisted pair is shorter, which determines that analog monitoring is only suitable for single buildings, small residential areas and other small-scale places. b. The expansion ability of the system is poor. For the built system, if you want to add new monitoring points, it is often a drag on the whole body, and it is difficult to add new equipment to the original system. c. Effective alarm linkage cannot be formed. Due to the independent operation of each part, the control protocols between them are difficult to communicate, and the linkage can only be carried out within a limited range

2. Digital video surveillance system

with the development of multimedia technology, video compression and coding technology, network communication technology and the rapid rise of digital video surveillance system, there are two types of digital video surveillance system in the market today, one is the video surveillance system with digital video equipment as the core, and the other is the video surveillance system with embedded video web server as the core

the increasingly mature digital video compression and coding technology and the popularization of computers have created conditions for multimedia monitoring based on PC. The rapid rise of this new video monitoring system partially replaces the analog video monitoring mode with video matrix image divider and video recorder as the core, supplemented by other transmitters. Its advantages are mainly shown in: a. the multimedia monitoring host of PC integrates many functions of video matrix, image divider and video recorder, which greatly simplifies the system structure. b. Due to the use of computer network technology, digital multimedia remote network monitoring is not limited by distance. c. Due to the use of large capacity disk array storage or optical disk storage, a lot of tape media can be saved, and it is conducive to the system to realize multimedia information query

however, with the development of PC based video surveillance and video recording system, some deficiencies have also been exposed in the actual engineering use, mainly the instability of the system. The group of PC based video surveillance and recording system vigorously promotes the compounding and high-end deep integration into a structure: compatible/industrial PC + video capture card + common/more reliable operation platform + application software. From the composition and structure of the system: A. when PC is used for 24-hour uninterrupted work, its performance is not very stable, and the stability of industrial control PC is higher than that of compatible PC, which is applicable to 5 The fixture itself has no fixed structure (for example, the metal wire can be clamped by winding, or two flat plates can be clamped in a more complex working environment. B. operating system: the system with Windows 98 as the operating platform, insiders know that there is a certain problem with the stability of Win98. If the application software is not very standardized at the same time, it is easy to have problems such as unstable work and crash in the process of use. However, the software of the video surveillance and video recording system based on PC It is implemented on windows 95/98/nt, UNIX, Linux and other general-purpose operating systems. At the same time, system files, application software and image files are stored on the hard disk. Video processing must input a large amount of data with high density. At the same time, the hard disk must be multiplexed. Ordinary hard disk logic (such as FAT32 of windows) cannot adapt, so it is very easy to produce system instability and cause crash. c. Application software: the system using simple application software cannot be used in the field of security. The application software of the video monitoring system should support multi task concurrent processing, such as surveillance, video recording, playback, backup, alarm, control, remote connection, etc. d. Video capture card: the video surveillance and video recording system is usually a multi-channel input system. The video capture card can be multi card or single card. Generally speaking, the single card mode has a high degree of integration, and its stability will be better than the multi card mode. Many ways of using one card along the way are easy to form hardware conflicts, which will have a great impact on its stability

embedded system is a special computer system with application as the center, software and hardware can be reduced, which meets the strict requirements of the application system on the function, reliability, cost, volume and other comprehensive requirements, that is, a special computer system tailored for the monitoring system

embedded system is mainly composed of embedded processor, related supporting hardware, embedded operating system and application software system. It is an independent "device" integrating software and hardware. Embedded operating system is a kind of real-time operating system software that supports the application of embedded system. It is a very important part of embedded system. It usually includes hardware related underlying driver software, system kernel, device driver interface, communication protocol, graphics interface, standardized browser, etc. embedded operating system has real-time efficiency, hardware related dependency Software solid-state and application specificity have prominent characteristics. Advantages and disadvantages of embedded system: a. the system is a special system, so the system is small, the instructions are simplified, and the processing speed is fast. b. The system data is placed in rom/flash memory, which is fast to call, will not be changed, and has good stability. c. The system has good real-time processing and stable performance. d. File management system is more suitable for a large number of video data. e. It is also difficult to be satisfied in terms of network function, audio and video synchronization, etc

embedded video web server mode. An embedded web server is built into the video server, and the embedded real-time multitask operating system is adopted. After the video signal sent by the camera is digitized, it is compressed by the efficient compression chip and sent to the built-in web server through the internal bus. Users on the network can directly view the camera image on the web server with the browser, and authorized users can also control the action of the camera, pan tilt, lens or operate the system configuration

because the video compression and web functions are integrated into a small device, it can be directly connected to the local area to achieve plug and play, eliminating a variety of complex cables, convenient installation (only need to set an IP address), and users do not need to install any hardware devices, just use the browser to watch. Compared with other monitoring systems, the embedded video web server monitoring system has the following characteristics: a. the control area is vast. The web server of the embedded video web server monitoring system is directly connected to the network, without the limitation of cable length and signal attenuation. At the same time, the network has no concept of distance, completely abandoning the concept of region and expanding the control area. b. The system has almost unlimited seamless expansion ability. All devices are identified by IP address. Adding devices only means the expansion of IP address. c. It can form a very complex monitoring network. The monitoring system based on Embedded Web server is used as the core, which is very different from the traditional analog monitoring and monitoring methods based on PC platform. Because the output of web server has completed the conversion and compression from analog to digital, it adopts a unified protocol to transmit on the network, and supports the remote video transmission across customs and routers. d. The performance is stable and reliable, and there is no need for a special person to manage the embedded web server. In fact, based on the embedded computer technology, the embedded real-time multitasking operating system is adopted. Because the video compression and web functions are concentrated in a small device and directly connected to the local area or wide area, plug and play, the real-time, stability and reliability of the system are greatly improved, and there is no need for a special person to manage it. It is very suitable for unattended environment. e. When the monitoring center needs to watch more camera images at the same time, there will be a certain need for the network bandwidth. The experimental method is to cut the width of 15mm or other dimensions at the heat sealing part of the plastic packaging bag

development of video surveillance system

1. Development direction of video surveillance system

front end integration, video digitization, monitoring networking and system integration are the recognized development directions of video surveillance system, and digitization is the premise of networking, and networking is the foundation of system integration. Therefore, the two biggest characteristics of video surveillance development are digitization and networking

2. Digitalization

digitalization is the feature of the 21st century and the inevitable development of electronic technology with information technology as the core. Digitalization is the passport to growth. With the development of the times, our living environment will become more and more digitalized

the digitization of video monitoring system should first be the transformation of information flow (including video, audio, control, etc.) in the system from analog state to digital state, which will completely break the structure of "classic closed-circuit television system is centered on camera imaging technology", and fundamentally change the way and structure of video monitoring system from information acquisition, data processing, transmission, system control, etc. The digitalization of information flow, coding and compression, and open protocol make the video monitoring system seamlessly connected with other subsystems in the security system, and

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