HD-CCTV is a new standard specified by a number of chip and system suppliers in 2009 for co-development of High Definition Surveillance Systems applications. Although this standard proposes a time that is less than two years to date, due to the advantages of its own standards, coupled with more and more manufacturers, the HD-CCTV standard can be said to have gradually begun in the current high-definition surveillance industry. The Open Network Video Interface Forum (ONVIF) and the Physical Security Interoperability Alliance (PSIA) have formed a three-way situation.
In simple terms, HD-CCTV utilizes the SDI link originally developed for the professional broadcast market, which is the transmission line from the camera-DVR in the analog security system that is now widely used, and on this basis defines the definition of high-definition video transmission. Handshake protocol for information such as video resolution and frame rate. Such an analog HD video transmission mode (HD-SDI) is the most important basic core technology in HD-CCTV. HD-CCTV camp supporters expect that the new standard will result in a more easily deployed, lower-cost alternative to an Internet Protocol (IP) system.
Talking about the IP system, it is currently the mainstream standard for high-definition video surveillance system applications. Due to the introduction of IP standards, high-definition monitoring solutions can truly gain practical value. The IP system greatly improves the video data carrying capacity, greatly improves the video image resolution, and it has advantages such as high scalability, extensibility (wide IP system coverage), and centralized management. The current ONVIF and PSIA are based on the IP program camp. Currently, they all have their own industry leaders. For example, ONVIF has IP camera sales giants such as Axis and Sony. PSIA also has brands such as Cisco, GE, Honeywell and Panasonic. In various exhibitions in the security industry in recent years, the IP-based high-definition video surveillance program can be described as a smash hit. However, from the point of view of actual IP systems used in security systems in recent years, they only accounted for 10%. The actual or actual achievements and the expectations of these manufacturers can not but say there is a big gap, which is not unrelated to the characteristics of the IP system, a simple analysis, the current IP system has the following problems:
1. Difficulties in the management of IP devices Although the good management and scalability of IP devices is a big advantage, but from the real establishment of such a management system, especially for the existing security system solutions mainly based on simulation , need to invest more manpower and material costs.
2. The cost of upgrading from analog systems is as large as mentioned in the previous article. The vast majority of current security solutions are based on analog systems. If you upgrade from an analog system to an IP system, there are various difficulties in rewiring, reinvesting hardware resources, and retraining personnel.
3. There is still technology to use IP to transmit data. One is that the back-end device can no longer obtain the original image. In some applications that need to save the original code stream or require high bitstream, it cannot be satisfied. Second, image restoration is a process of encoding-decoding, which brings about a delay (above 50 ms). It cannot be satisfied in some occasions where real-time requirements are high.
In contrast, HD-CCTV can be said to have inherent advantages. From the beginning of the design, it considered how to solve various problems brought about by the IP system at the time. In simple terms, it mainly has the following advantages:
1. In the wiring scheme can follow the results of the old analog system, without re-wiring, device management can also follow the old analog system architecture, upgrade from the old system, only need to replace the hardware devices (cameras, DVR, etc.), no need to have Other inputs. It also eliminates the need for new knowledge training for system changes.
2. Undistorted reliability: Unlike digital surveillance data, which is compressed and then packetized over the network, uncompressed digital data is transmitted over the coaxial cable without distortion.
3. High-definition real-time image: It does not generate compression and packetization during transmission, and it does not cause image delay problems like normal digital high-definition. It is particularly suitable when it comes to real-time monitoring.
4. Provide high-definition images for intelligent surveillance (IVS): HD-CCTV provides uncompressed high-definition images with guaranteed image integrity, providing the best source of HD images for smart surveillance.
In fact, the most fundamental benefit of HD-CCTV is that it can be smoothly upgraded from the current large number of analog video surveillance solutions to high-definition solutions. This point, whether it is the end-user, to the system integrator, or now a large number of analog camera manufacturers, are willing to accept a way.
Objectively speaking, IP-based standards and HD-CCTV have their strengths, but in the current security industry, the future of HD-CCTV is exciting and exciting. Of course, HD-CCTV has only experienced a short period of time since it was proposed. No matter whether it is introduced from the camp members, marketing, or technical difficulties, it is still in its infancy. For example, the transmission distance of HD-SDI and the traditional SDI. In comparison, there is still a small gap, HD-CCTV cameras and DVR options are very small, the cost is relatively high. Marketing efforts are also far less than IP's high-definition monitoring solutions. However, as technical difficulties are overcome one by one, more and more companies and manufacturers will join in, the costs of hardware and solutions will become lower and lower, and they will attract more and more attention from the security industry.
