All the universities have known the trend of the security intelligence, the network surveillance camera (IP Camera) can use the Ethernet to power the network remote connection through Ethernet, which can save the power cord. Trouble and reduce the cost of wiring construction, plus the advantages of elastic storage space, system scale expansion, etc., make network monitoring gradually increase.
Originally, the monitoring market in the IP Camera’s holiday, the traditional simulated photographic system seems to have to come to the end, but recently simulated photography camp but frequently blowing counterattacks, constantly introducing HD-“a resolution up to 720P, video Format simulation scheme. Among them, CVI, TVi, AHD are most eye-catching.
In this IP Camera completely replaces the transition period before the simulation, the simulated photographic system still has its vitality. The three major programs of CVI, TVi, and AHD not only take the lead in resisting the IP Camera, and each other will fight each other. Since the current simulation camp Sanxiong is prosperous, each claiming that it can surpass IP Camera, and respectively advertised the high-definition faucet, so that the security monitoring specification market enters the big mixed warfare, the user will inevitably create confusion.
Therefore, this paper specifically introduces the three simulated HD programs of the Thousands of Snow, indicating that they are born, the market foundation, and simply explain their own advantages and disadvantages, let readers choose some reference. Basis.
Why does there be analog HD market?
In this monitoring of the intelligent times, the simulation camp dare to launch analog HD to compete with it. It is very important reason to simulating the photographic system still has a small market share. Therefore, the simulation camp will not be so easy. Exit the market, but will continue to seek reform programs that can approach the IP Camera performance to ensure existing market, it is a very important direction, which is also the reason for the simulation of HD programs to be continuously launched.
However, if it is just a device manufacturer’s own subjective will, the simulation HD program is not necessarily a wave of waves, and the simulation camp is still vital, and there are two important factors. One is that traditional engineers are online knowledge, Technology is unfamiliar, and another factor is that the price of IP Camera devices is relatively expensive. Therefore, the equipment manufacturer of the simulated camp provides a knowledge of the installation of the wiring. It does not require re-learning. The price is similar to traditional simulation, but in performance, it can approach the IP Camera solution, which can be said to meet traditional engineers. And low-level passengers in this transitional demand, naturally can get warmly immediately.
CVI, TVi, AHD common advantages and disadvantages
CVI, TVi, AHD are three comparison in these simulated HD programs, which are also based on simulated coaxial cable transmission, translational transmissions for progressive scans.
CVI, full name “HDCVI), which is independently developed by Zhejiang Dahua Technology Co., Ltd., which is announced at the end of 2012;
Tvi, HIGH Definition Transport Video Interface, HDTVI, R & D from TechPoint Inc from US Silicon Valley, is also a specification of the main promotion of Hangzhou Haikangwei TV Co., Ltd. As for AHD, the full name “Analog High Definition” is the simulated HD solution introduced by Nextchip, South Korea.
As mentioned earlier, if you want to upgrade from traditional simulation to CVI, TVi, AHD these simulation HD programs, it is very easy to install the wiring, because CVI, TVi, AHD follows the transmission pathways and methods of traditional simulation, users To upgrade your device, you don’t need to change the infrastructure of your system, even just replace their original camera and digital monitoring host (DVR) to replace a new camera and DVR, you can get a new HD system. It can be said to reduce the complexity of construction deployment, reduce costs, and the technical requirements of the construction personnel, and even simplify the complexity of subsequent maintenance.
However, this is easy to see from the perspective of traditional simulation upgrades. If you make engineers who have the same cooked network equipment installation and traditional construction wirings, it is purely compared with the complexity of the construction, I am afraid that simulation HD is still more than IP. Camera is complicated. After all, on the line, IP Camera is using a general network cable, nor does it need to set up a power cord, and IP Camera can connect back to the host with a single line via the IP sharing, and the simulation system is every Both the camera need to wire back to the host, there is a much trouble under the phase; on the installation, the simulated camera will necessarily need to match the DVR. IP Camera can utilize a general computer device; on the system restart and setting, IP Camera can remotely Remote control, the simulation program needs to be set up. So, which is simple to easily, but also to see which case itself is in the above.
In addition to some of the degree of construction wiring, CVI, TVi, AHD is compared to traditional analog and IP Camera, and there are also their advantages on images. The three compared to traditional analog images, except for higher resolution and clarity, there is no bright color crosstalk, the transmission distance is significantly increased, and the coaxial cable can achieve a high-definition transmission of 500 meters, using twisted pair The transmission distance of about 200 meters, which also has the advantages of the traditional simulation system compared to the IP Camera image, that is, the image is transmitted from the front end to the back end without compression, the image does not have delay, the image can avoid compression damage Distortion problem.
However, because their images are not compressed, compared with IP Camera, the back-end data naturally also accounted for large storage space, plus transmission distances, if the device is equipped in a wide range of space, inevitable construction There are many DVRs, compared to the lack of flexibility to IP Camera, and therefore the simulation HD system is suitable for small and medium-sized monitoring spaces such as retail, stores, home markets.
Differences in CVI, TVi, AHD
However, even if CVI, TVi, AHD is common, it is an essentially a lot of products, but they still have their own characteristics and advantages.
In the three specifications, CVI launched earlier, and since a launch struggle to become one of the standards of the HDCCTV monitoring system alliance, it supports NTSC and PAL system, two color TV broadcast standards, 960H / D1, ISP and TX two in one The front end chip, the construction cost belongs to the intermediate price in the three programs. Although CVI has opened technology as an industry standard to openly authorize a third party, because Zhejiang Dahua itself is a device business, not a neutral chip factory, CVI has been developed from the specification to the production of chips, and then to support camera and DVR The manufacture of products, is currently the Dahua’s own bag, close to monopoly, lacks the participation, matching of other chip manufacturers and equipment manufacturers, other peers do not help but have doubts, do not dare to use their specifications, and thus also affect The generalization of this specification, plus the CVI specification camera can only match the CVI specification DVR, which greatly limits the development of CVI products, resulting in the least one of the three major programs in the three major programs.
As compared to this, TVI is an open ecological circle, with more than 100 well-known DVRs and camera manufacturers to participate in and investing in the competitive environment, can develop more series of HD products for users. It doesn’t matter of 720P or 1080p, and can be compatible with different label simulated cameras and DVRs.
The TVI is probably in terms of transmission, although the transmission capacity of three specifications is almost, many measured reflection points out that TVI is the shortest transmission distance in three specifications, actually only 300 meters, for wire The requirements are also the highest, but the effect in 200 meters is better than CVI. However, in the actual application, it is not so important that the simulation HD can reach more than 500 meters. It can even be said to be a false issue, because of the current actual project wiring, 500 meters this distance is also None of practical value, after all, more than 300 meters of wiring is basically replaced with fiber converters, so, especially to emphasize transmission distances, there is no significance for simulation HDs.
Since the TVi support manufacturer is a wide range of applications, it is the highest in the three programs, so it also limits the market share of the low-cost market in the simulation of camp.
As for AHD, it is mainly divided into three levels, respectively:
(1) AHD-L, the resolution is only 960h, but its sharpness and line are between 960h and 720p, which is the product produced from traditional simulation transitions.
(2) AHD-M, current mainstream format, clarity, and line number are quite equivalent to 720p IP Camera.
(3) AHD-H, the sharpness and the number of lines are comparable to 1080P IP Camera. Its performance and other two specifications are not large. In addition to more complacent of 960H / d1, AHD front-end chip is also ISP and TX two in one, the least pick up line on the transmission.
Generally speaking, although AHD has developed late, because of the cooperation of all family manufacturers, the model is involved, the development speed is very fast, and the supporting is also more and more perfect, and it can support things. It can be compatible with TVi. Replace the simulated camera and DVR of different labels in the same HD picture form. It is the cheapest one in three programs that belong to an affordable product, so it is also one of the current market share in three programs.
CVI, TVi, AHD, these three recently look quite analog HD programs, although in a long way, they will finally give IP Camera, but at this stage, they have a vast group of low-cost markets. Traditional engineering companies, I want to be a good gospel from the simple upgrade of the traditional simulated equipment.
Objectively said that these three specifications do not have any side of the overwhelming advantage, choose which solution, end see everyone’s existing conditions and lock demand. If there is only Zhejiang Dahua’s equipment in Hand, CVI is the only choice, compared to the application of the ecosystem than the ecosystem is more open, and the compatibility is wider. However, AHD can support more image formats compared to TVI. For different transmission lines, the price is also cheaper, so it is the highest recent specification in the market, but also people who pay attention to C / P values. Good choice.
In any case, the simulation system will not walk into history so quickly, and as a transitional product, the three major programs will continue to have a period of time. It can be expected that the three major programs should be stabilized in intelligence and high-definition. The ground, enhanced the clarity of the image quality, the stability of the product, and continuous amplification support will be the direction they work together.