In the field of education, with the advancement of the national "School-School Link" project, more and more schools have a high-bandwidth LAN environment and gradually access the Internet. On the campus network architecture, digital technologies such as e-library and VOD on demand have been widely used. Traditional e-learning methods are gradually moving towards pure digital, from digital cameras to non-linear editing, from paperless office to electronic lesson preparation. Various digital subnets of the school have emerged one after another, and education is improving her mission of teaching and educating people with newer technological means.
At the same time, in response to the phenomenon of more and more concealed cheating in examinations in recent years and more and more technical methods of cheating. TV monitoring systems have been set up in designated examination rooms of the National Unified Education Examination in the area. For example, the Guangdong Provincial Examination Center has issued notices to the admissions offices and self-examination offices in Guangdong cities. The designated examination venues for the National Unified Education Examination in Guangdong Province will establish a television monitoring system within the next three years.
The traditional test room TV monitoring system adopts analog monitoring, which requires a long distance between each front-end camera equipment and the monitoring center. To this end, it takes a lot of manpower and material resources to penetrate the wall, bury the pipe, and lay the line. And if the distance between some test centers and the monitoring center is too long, in order to avoid affecting the transmission control effect, you need to add some specific relay equipment. In addition, in the monitoring center, in order to realize the monitoring, display, and recording functions, many complicated equipment such as monitors, long-delay video recorders, screen dividers, and control switching matrices are required. Operators also need some training to master many Operation of electrical equipment.
In this form, due to the need for additional wiring and non-standardized equipment and professional management personnel, traditional monitoring methods are becoming increasingly unsuited to the needs of schools for functions, regardless of construction cost, construction difficulty, and final application. Xunfei digital monitoring system will be the first choice for schools to choose monitoring methods. The typical arrangement is as follows: Since the arbitrary communication of audio and video materials is realized, as with VOD and other systems, digital monitoring is actually an application subnet of the campus network. In this environment, the LAN architecture and switch settings are often completed. The school only needs to You only need to purchase cameras, gimbals, and decoders, and no complicated training is required for teachers. For users who only need fixed-point monitoring, the required equipment is simpler.
The overall structure design and construction of the examination room remote monitoring system follow the principle of "unified planning, unified specification, distributed implementation, emphasis on effectiveness, safety and reliability". At the same time, in order to achieve the overall goals of the system, the design of the entire system should adhere to the following principles:
Reliability and security principles:
Fully consider the selection of reliable and mature technologies and products. The reliability of the system is an important prerequisite for the successful construction of the system. In the design of the system, multiple layers of security protection mechanisms and measures ensure the integrity, accuracy and security of various materials.
Openness and standardization principles
In the system design, an open design idea is adopted to ensure a perfect interface between the system and other application systems. And it has adopted widely used industry standards and technical standard specifications to fully integrate and connect with other application systems.
Scalability and network principles
It fully meets the existing conditions and requirements, and can also take into account the development and progress of future technologies and the growth of system requirements. The system has strong scalability. The existing network can be used to remotely transmit the front-end video stream, and any computer in the network can be used as a sub-control point for remote monitoring, control and command. The expansion of network control points only means the expansion of IP.
In short, this system makes full use of today's most advanced equipment, networks and technologies to achieve modern, intelligent, digital and networked management.
With the development of informatization in various industries, the establishment of a unified monitoring information network, integrating monitoring services into the entire information management system, has become the main direction of current monitoring needs. Beijing Xunfei Information Technology Co., Ltd. has accumulated many years of experience and technical experience in digital image monitoring and distributed network systems, and has advanced a comprehensive set of system solutions based on hierarchical remote network monitoring, which reduces the investment in repeated construction of the monitoring system. Waste, also meets the needs of centralized monitoring information management, enabling various business functions to share monitoring information.
According to the requirements of the broadband IP network system for video surveillance services, the Xtream surveillance system uses distributed network video access, centralized access control and resource management, and a multi-level organizational structure . Distributed network video access refers to that the monitoring front end connects the monitoring video to the entire monitoring system network, instead of connecting to the monitoring center. Centralized authority control and resource management refers to the use of a dedicated server system to control user access rights and monitor front-end storage requirements, and to uniformly plan and allocate resources. The multi-level organizational structure is a hierarchical organizational structure adapted to the system application industry. It performs authority control and hierarchical management according to different business departments, and combines with the original information management system.
The Xunfei digital monitoring system is an organic part of the campus network. This subsystem provides a comprehensive view of every corner of the campus by setting up cameras in each classroom and important locations on the campus. It is an advanced audio and video that integrates teaching and management. Transmission system. This subsystem is combined with the overall architecture of the campus network, which enables audio and video to communicate with each other throughout the campus. It is not only conducive to the exchange of teaching content, but also to the administration of teaching affairs and examinations. Lessons and the training of young teachers play a pivotal role.
3.1 System composition:
The structure of the system is as follows:
The system consists of several monitoring subnets at the front end and a monitoring management center at the central end. The monitoring subnet includes front-end camera equipment and front-end data acquisition equipment:
Front-end camera equipment: camera, gimbal, decoder, pickup.
Data Acquisition Equipment: Embedded Video Encoder and Acquisition Workstation
Monitoring management center: monitoring management server, master control workstation, mass storage equipment
The front-end video encoder or acquisition workstation compresses and processes the audio and video signals collected by the camera, converts them into digital signals, and transmits them to the campus monitoring and management center through the campus network. After the image is transmitted to the monitoring and management center, it is uniformly processed by the monitoring and management server, and the image is posted on the campus network in a multicast manner. The relevant staff can monitor the school situation through the large screen in the monitoring and management center, and the teachers and employees of the school You can also browse the images you want to watch on any PC on the network through authorization. Even if the school's leaders and relevant persons are not at school, they can monitor the school situation and manage the monitoring equipment at home or elsewhere through the Internet. At the same time, in the general control center, the monitoring management server records all the campus conditions in the center. Once an unsafe situation occurs, the image is retrieved through digital query as a research certificate to assist the investigation.
The anchor function of the monitoring management server satisfies the problem of multi-person access. In the past, digital video surveillance used on-demand. In this way, once multiple people access the same camera at the same time, the image will be unstable and the picture will not be smooth. Now With the multicast function, this situation does not occur when multiple people access the same image, that is to say, the effect of one-person access and multi-person access to the image is the same, which is more conducive to meeting on-site monitoring, especially such as examination room monitoring. Happening.
3.2 Monitoring Management Center
Configure the network master control cluster server in the monitoring management center, including the sub-control workstation. An overall workstation is configured in the center. The main control / sub-control workstation can monitor any of the multiple video and audio sent by the encoder on the 16-channel monitoring front-end on the same screen. The front-end PTZ and lens can be controlled by authorization; Real-time transmission to the corresponding master control station, the master control station will notify the management staff in an audible and visual manner; the master control station can also perform audio and video interaction with multiple front-end interaction points, and the leader can give orders to the front-end staff.
Set up a monitoring management server in the monitoring center. The monitoring management server provides hierarchical management of front-end video encoders and collection workstations, and hierarchical user rights management. The server can use industry-standard mass storage computer servers and install dedicated XtreamServer software. , The user can store the front-end audio and video data on the central server in real time through the network according to the needs; the server database records all video data information (video files can be distributed to various monitoring encoders or servers), alarm information, monitoring point information, other Data information, general users log in to the server through WEB, and can query any authorized information on the unified interface; for the network environment that does not support multicast between the front end and the center, the server provides unicast to multicast data forwarding, so Multiple people in the center view the front-end real-time stream to save a lot of bandwidth.
4. System functions:
4.1 Monitoring Workstation Xtream Producer
4.2 Xtream Controlle
- Full real-time audio and video synchronization: 8 channels / 16 channels of each host in full real-time (with a delay of no more than 0.1 second) synchronized video and audio acquisition, compression, storage, network transmission, and playback; each frame is 25 frames / second, with a standard resolution of 352 × 288 , The maximum resolution is 720 * 576; it can also reach 25 / second per channel during playback, without losing frames, it can be enlarged to full screen, and local details can be enlarged without limitation;
- Save storage space: The industry's top compression technology MPEG-4 algorithm is used, with a compression ratio of up to 1: 500. Each channel only needs 60 to 120M hard disk space (including video and audio), and the bandwidth required for network transmission is adjustable from 10K to 2M.
- Four recording modes: manual recording, timer recording, alarm recording, motion detection recording;
- PTZ control: support three variable control of lens aperture, zoom, focus; support all-round control of PTZ; control can be performed at monitoring workstation and network sub-control terminal;
- Alarm management: 16 inputs, 8 outputs, free definition of linkage rules, alarm information storage, network transmission, query;
- Network sending: support multi-user network monitoring, support multicast output;
- Security management: important operations require permission password verification to prevent unrelated persons from viewing, deleting, and modifying image data; unauthorized persons cannot access remotely;
- Intelligent application: regular recording according to time period; image has dynamic detection function; compression ratio, image quality, code stream can be adjusted;
- Friendly interface: full Chinese graphical interface, simple and practical, easy to operate, no training required;
4.3 monitoring server Xtream Server
- At the same time receiving audio and video data of any monitoring point in the network, it can realize 1, 4, 9, and 16 screen division and multi-screen monitoring; you can group monitoring points to automatically poll and view;
- The monitoring workstation and master control workstation can be one-to-one, one-to-many, many-to-one, and many-to-many; support remote monitoring and remote control (PSTN / ISDN / DDN / Broadband) across routers; support multicast function; support Multi-user multi-level management; remote real-time monitoring and retrieval of on-site data.
- Level authorized to control any PTZ and lens of any monitoring point;
- Can display on all channels or single channels, can be connected to large screen projection or rear projection
- The monitoring center uses a tree structure to organize each monitoring point, which is easy to operate; it has good scalability and is not limited by the number of monitoring points;
- The subordinate monitoring station automatically receives alarm information, and prompts the administrator with sound, light and text messages;
Remotely configure monitoring workstations;
- Can interact with multiple interactive workstations for video and audio, and issue commands to the front end;
- Configuration, management and information release of monitoring stations and monitoring points;
- The audio and video data of the front-end monitoring point can be stored on the server, and the user can order the historical data stored on the server;
- Provide WWW service, so that authorized users can check the monitoring point situation in real time through WWW;
- Provide user authentication and multi-level authority control (forbidden to watch, monitor, and monitor control);
- Provide data proxy forwarding. Only one share of bandwidth between the monitoring server and the monitoring workstation is required to meet the real-time viewing of multiple people. For network environments that do not support multicast, the multicast proxy function is provided;
- Provide network backup function to ensure data integrity and security;
- Provides the function of searching, querying and browsing historical data based on web pages; users can query historical data by camera number and date, all operations can be achieved by clicking on the web page;
- Provides network-level proxy server traversal, real-time monitoring of internal network monitoring points on the external network.