How to select a camera for video surveillance, part 1. See video cameras. Analogue HD cameras AHD, CVI, TVI What's better for tvi or cvi

The popularity of analogue cameras is gradually falling under the onslaught of more modern digital devices that provide higher image clarity. However, transferring all the footage to digital cameras causes significant expenses, since all the wiring will have to be reworked, and analogue devices will have to rewire cables, and digital devices will have to rewire the cables.

Such modernization of the network costs a pretty penny, and it is necessary to construct IP video cameras, as well as a video recorder for them. Some of the stench has not been reduced, although it cannot be ignored that the image brightness that is removed is more effective than that of analogue competitors.

TVI is a standard for transmitting audio and video signals from separate parts 720p/1080p, as well as signals from PTZ cameras via a coaxial cable over a distance of up to 500 m. TVI video cameras provide maximum image detail and Dyed bright color. Moreover, the TVI signal has a higher resistance to crosstalk than the original analog signal.

It’s no less true that not everyone is happy with this kind of modernization, and not everyone is excited or able to so thoroughly redesign the entire topology of the network. Fortunately, the remaining fate of analog cameras, one might say, inspired another breath. We are talking about new analogue standards of high quality. Vikorist and primary coaxial cables, such video cameras, are careful to see the picture as Full HD 1080, so this parameter is not compromised by digital video cameras. At the same time, the price of analog cameras of the new generation is significantly lower than that of digital cameras.

At the same time, three analogue formats of high quality have been expanded – HDTVI, HDCVI and AHD. It’s true that the rest of the trio is slightly out of line with the front row, and currently only supports the separate production of HD 720. In the near future, new devices will hit the market with dtrimko Full HD 1080, but at the same time those who are moving are still alive. The HDCVI format has its own characteristics, which is the topic for this article, and for now the report will focus on perhaps the most promising of the new formats – HDTVI.

Data transmission via HD-TVI

Divided by the Hikvision company, the HDTVI format is a new development. This standard for transmitting images over an original coaxial cable with high resolution is Full HD 1080. This picture clarity is achieved through patented technologies for the reduction and separation of signals developed by Hikvision. With many advantages of the HDTVI format, it is possible to note the fact that it cannot handle the power of both a coaxial cable and plug-in connectors.

To put it simply, if you buy cheap cables (we don’t take cheap Chinese cables with poor quality), you still won’t spend money on the image. And at the same time, you are guaranteed to avoid signal jamming or wasting packets, which will ensure that you see images in real time without any problems.

Pros and cons of HD-TVI - technologies

It is clear that the powerhouses of technology do not reveal all the secrets of the technology, but it is clear that such high viscosity from frozen cables can be achieved by innovative solutions of signal transmission. Color, color and brightness parameters are distributed in the most effective manner. The result is obvious - the client receives images of the highest quality, which are transmitted over the old cable, which a standard analog video camera has already processed more than once. With a normal cable, the transmission of a clear picture can be ensured over a distance of up to a kilometer, and modulation can also be used to minimize the negative input of the transcode, which can be transmitted through the work of a nearby device. Nya.

However, the HD-TVI format, which is equal to other analog standards of high-quality production, does not have any additions or shortcomings. The most important of them is the importance of supporting multihybridity “behind the minds”. So, for example, an AHD video recorder can easily handle the range of video surveillance that comes with both analog and digital cameras, and the HDTVI version will be able to additionally use the analog video decoder.

So the axis is not entirely correct, but there is a difference, obviously, but it is only for the reader. The client doesn’t care how many wires and microcircuits are in the case of his device - everything works the same way. The decoder is simply installed in the HDTVI video recorder at the factory. And because of the high price, HDTVI installation is not very effective. Of course, IP devices will still be more expensive, but HDTVI will be about 20% more expensive than AHD.

On the other hand, this is a real plus. Most often, a video surveillance circuit is not built from scratch, as it is necessary to upgrade the existing circuit to ensure higher viscosity of the robots. And the transfer of all the footage from analog cameras to digital ones will involve significant costs, so you will have to not only change all the equipment, but re-lay the twisted pair instead of coaxial cables. And if you install HD-TVI video cameras instead of IP cameras, you can easily make do with external coaxial cables, which will save your budget. In this case, the image clarity will not be as bad as that of digital IP video cameras.

Visnovok

Strictly speaking, from the perspective of the end client there is no great difference between different high-resolution analog standards. Minimum performance – AHD is still compromising the maximum possible, but rather the maximum possible technology, which standard is predicted in the great future.

HDCVI is a standard of closures, which is indicated by the price of HDCVI possessed and at the pace of technology development, and is indicated, unfortunately, not by the highest rank. HDTVI is also a slightly higher price for video cameras and video cameras, but it is also a secure standard, which allows us to assume that it is rapidly developing.

True, the HDTVI technology itself is not cheap, and its further development is entirely dependent on the company’s investment. Hikvision" Which of the formats will take the leading position is just an hour away, but it can now be confirmed that HDTVI, at a minimum, is in competition with other current analog standards.

AHD

Despite the fact that analogue video surveillance systems run into the boundaries of the standard PAL color television systems (vertical capacity of 625 TVL), their potential is far from being exhausted.

Recently, there has been a trend toward an increase in the horizontal resolution of analogue cameras, with the aim of introducing a matrix with a higher degree of separation, and to ensure the transmission of the signal that is formed by a similar analogue camera, there has been increased pressure the last thing in a row - this is how the 960H standard came into being, having lost the same PAL vertical permission. Ale cameras in a separate building are 700TVL, for example 1000TVL, 1200TVL - there is no connection to vertical TV lines, these values ​​are subjective and lie within the type ї matrix, and itself within її horizontal resolution.

In order to be able to convey more information about a video frame, it is necessary to adhere to the established PAL/SECAM/NTSC standards. The current development of computing technology makes it possible to vibrate resource-intensive calculations with previously unprecedented speeds, which allows the development of complex mathematical algorithms for digital signal processing.

The results of the work have been an increase in the separate data and throughput of analog video surveillance systems, which have become AHD standards - Analog High Definition - Analog High Definition Systems .

Equivalent to its analog predecessors, the analog AHD standard provides clearer color reproduction and greater image separation.

Objects designed for analog video surveillance systems can be upgraded to an analog high definition system by replacing PAL/960H standard video cameras and video recorders with new AHD cameras and video recorders without the need Details of the installation work when laying a new cable.

This standard is more important for analog systems, the middle of data transmission is the primary coaxial cable, and less capable of connecting cables, the lower digital standard HD-SDI .

In addition, aligned with PAL, the AHD standard is a unique subsample for colors and brightness, without color subsampling, like Chroma and Luma for the PAL standard.

TVI

Today, the world has a large number of coaxial lines for connection. As development progresses, more than half of these cameras will be replaced by more modern cameras, which will provide a high level of separation. The need to replace the cable significantly complicates the process and increases the cost of payment for the end user.

HDTVI is an ultra-modern standard for transmitting audio and video signals to separate buildings 720P/1080P and control signals for PTZ cameras via coaxial cable. The working distance with this technology at a standstill becomes close to 500 meters. HDTVI technology can be used with lightweight installed and installed solutions for organizing video surveillance with high-quality images.

Advanced solutions for HD-TVI technology:

High quality imaging - 720/1080P
-Transmission via coaxial cable of both audio/video signals and cable signals
-When transmitting an HD signal, there is no loss of image brightness
-Signal transmission range up to 500 meters
- It is not difficult to upgrade an analog system to HD-TVI.

HDCVI

1. Price: the same HD CVI cameras and analog cameras are different, so the difference in price between the two tested products is close to 15%. The difference in the price of a 4-channel recorder is probably the same, maybe even less.

2. Analog video signal. There are differences between video standards and analog ones. It looks like the availability of analogue equipment for video caution will be wider for another hour after a few years:

Low level of ownership, reliability, signal transmission over long distances, ease of installation and adjustment, which does not require special skills.

Well, about the advantages of HD-CVI technology over its simple analogue:

1. Separateness of the image. It is stated that HD CVI cameras will be available in 720p or 1280×720, which is significantly lower than standard analog cameras - 700 TVL maximum.

2. Entirely adapted to current monitors. May all daily monitors display 16:9 display on both sides. The matrix of the HD-CVI camera is of the same quality, which, in its turn, allows you to capture the image without any problems. The matrix of a standard analog camera has a 4:3 aspect ratio. It is important to note that this format is more appropriate for the implementation of security video surveillance. However, today there are practically no shortages of 4:3 monitors, because they face an undeniably high price. Apparently, a 4:3 picture when displayed on a 16:9 monitor is deformed in one way or another.

3. Expansion of functionality. Progressive rosette. When this technology is installed, menu control and transmission of audio and video signals are carried out over one coaxial cable. The transmission range of signals without force becomes close to 500 m-code.

The pouches are listed in the level table below.

17.12.2015

HD-TVI (High Definition Transport Video Interface) is a new technology for transmitting high-definition analog video signals HD 720p and Full HD 1080p via coaxial cable. This is to replace the outdated PAL TV standard, which appeared in the middle of the last century, and is still used in analog video surveillance systems.

HD-TVI is not the only alternative for transmitting high-quality analog video signals Full HD 1080p and HD 720p via coaxial cable, compared to competing technologies such as HD-CVI and AHD, according to the translation gi.

With approximately equal statements of the characteristics of the technology for transmitting high-definition analog video signals over coaxial cable, an important factor in the competitive struggle will still be the same amount of bandwidth as HD-TVI claims more than HD-CVI and AHD. A larger bandwidth obviously transfers more power to the cable and otherwise reduces the maximum capacity of the cable. It is clear that competitors are replacing the maximum cable length for HD-TVI up to 300 m, leaving them with the same 500 m. Prote, as we can judge the results of the experiment, it is difficult to achieve good transmission speed for HD-TVI video signals at distances close to the stated 500 m, and then move them, even for the sake of reduced speed. There is already a lot to be said for the given task and what will be acceptable to the video signal.

It is a good thing that was at a time, the same factor, Yaki Bezpo -Serdanyo, is not in the techic characteristics of the new technology, Ale is more than a native of the virihedral of Virishalnno, the competitive Borotbin Standard Analogue signal for the Coacty cable. HD-TVI technology, known as HD-CVI, is developed and tightly controlled by one video surveillance system manufacturer - Dahua - and was created by an American integrated circuit manufacturer - Techpoint. It makes HD-TVI more democratic and accessible to videographers. Sucking for HD-TVI Standing a third-line outbuilding, bloomers at the SPIVPRASI with Vobornikov that is the most sewn of his technology, there is a bilsh vidkrit, the dinemino, nyzh confusing the patents of the technology. Currently, HD-TVI technology is actively promoted by leaders in the security market such as Hikvision, AVTech, IDIS, TVT, ITX and many other video surveillance systems that support its rapid advancement and development.

Video review of testing to our Youtube channel :

Advances in increasing the bandwidth and separation of analogue video surveillance systems have led to the creation of many new high-definition standards. The widest middle ones are AHD, TVI and CVI.

These standards are inconsistent both with the analog PAL format and among themselves. However, once you upgrade your video security system, you will not be able to change all installed components. The AHD, TVI and CVI standards use the same coaxial cables that are used in the analog module warehouse. Thus, during modernization it is enough to update the cameras and recorders.

AHD

This standard implements partial output from frames in PAL format. The AHD signal is identical to analog and has the same configuration and parameters as the classic TV video signal (PTVS speed). However, the composition has essential features:

• Frame-by-frame progressive rosette. This means that the AHD standard allows for the transmission of additional frames at a speed of 25 fps;
• the number of display elements has been moved vertically (up to 720 rows with 1280 points per skin). This made it possible to increase the frame rate to 40 ms and the upper frequency to 16.84 MHz. As a result, the primary part of the signal is very close in geometric parameters to a digital HD signal;

Essentially, AHD is a modernization of the analog standard based on fixed frequency modulation. This technology allows you to transmit a signal right up to Full HD 1080p without any expenses and a distance of up to 500 m using a standard coaxial cable type RG-59.

Otherwise, it seems that with the help of AHD recorders and cameras, it is possible to organize analog video surveillance using IP systems, without the need for advanced configuration.

HD-TVI

A new analog video standard that allows you to transmit a signal with a resolution of up to 1920x1080 pixels in addition to the PAL standard.

The HD-TVI format was developed by Techpoint, although Merezha’s authorship is often attributed to HikVision. We recognize the standard, which can be followed by any manufacturer of video surveillance technology.

HD-TVI is based on a changed technology for forming and transmitting signals. The standard transmits color and brightness externally to the video signal, which eliminates the accumulated transcode and ensures a clearer image.

In addition, TVI implements an algorithm for forward signal processing with further quadrature amplitude modulation. This makes it possible to transmit video over a standard coaxial cable that uses a 75 ohm cable.

CVBS

New color TV signal (PCTS speed) in SECAM, PAL and NTSC standards. CVBS is a composite video signal that often interferes with image transmission in analog cameras.

VIN is a mix of synchronization signals and color signals (a mix of red or blue color video signals with a brightness signal). Color synchronization pulses, as well as small frame shifts, guarantee stable image display on the monitor screen.

HD-CVI

CVI (Composite Video Interface, high-quality composite video interface) is an analog technology that is based on signal transmission over a coaxial cable.

HD-SDI

This non-analog standard is based on the idea of ​​using cable coaxial lines to transmit a high-definition digital signal. SDI has an important advantage over IP systems: in addition, there are any delays in the transmission of the video signal associated with the interconnected channel or the hours spent on image processing in the video camera itself. This advantage is especially relevant for systems with flexible PTZ cameras, since the second delay in the display is critical for them.

The transmission range of the video signal in HD-SDI systems depends on the type of cable being used. In this case, the signal from the video camera to the device that is being recorded is transmitted practically without loss of capacity. The image cannot reach the recipient unless it is critically extinguished in the middle of transmission. Statements for the HD-SDI standard:

• RG 59 - 50 m;
• along RG6 – 100 m.

Support for IP, HD-SDI and analog video standards

Analog video security systems come with low cost, no interruptions, and a lot of cables to run out of. To re-look, you can vikoristovvati pobutovy telepriymach. The main drawback: the unsatisfactory brightness of the video.

IP systems allow you to use the network infrastructure of LOM and SCS. There is no limit to the number of megapixels. The camera can be connected directly to the Internet. Sered Nedolikov:

• delays during signal transmission, delays in IP-dividing;
• There is a limit on the maximum length of the cable (90 m according to SCS standards).

The HD-SDI standard allows you to upgrade the analog video surveillance system to capture HD quality. In this case, you can use other connections based on the coaxial cable. When used in IP systems, the HD-SDI standard does not interfere with signal transmission. However, there is also a transfer of connections to the cable, and also to the cable itself, connections and sockets.

The main advantage of IP cameras is the fact that there are a lot of megapixels required when transmitting a signal. With the advent of analog video caution, great changes began to occur. And so as not to get lost, I have written this cheat sheet as a short overview of all analog video security standards.

How to decrypt CCTV

It’s not surprising that the abbreviation CCTV is not a standard for transmitting video signals and stands for closed-circuit television system. What is the most important caution!

In other words, CCTV is video surveillance, a process that results from the installation of optical-electronic devices used for visual control or automatic image analysis (automatic recognition of individuals, government numbers, etc.).

CCTV does not share video caution between digital and analogue.

Options between analogue and digital cameras

The principle of substitution between them at the external interface. In addition to the analog camera, the IP camera contains an analog-to-digital converter (ADC) and an Ethernet edge interface.

With new optics (lenses) and matrix, IP cameras have many important advantages in terms of image quality. The advantage of IP cameras lies in the fact that there are no losses in the middle transmission (in the cable), since the digital method of signal transmission is used. The connections between stationary IP cameras have a maximum cable length of 90 meters, which corresponds to the standards for local computing lines.

Some analogue cameras suffer from reduced signal-to-noise ratio due to larger cables. If the cable is longer, the code will fit better in the image. However, the maximum length of a coaxial cable is not limited to 90 meters and in some current standards it can reach 1200 meters.

High definition television

The maximum available vertical separation for analog systems, which is typical for PAL TV standards, is 625 rows with 720 display elements in each row - this is how a standard analog color signal can be characterized, divided into 196 6 for color TV systems.

Obviously, in order to improve image clarity during analog transmission, it is necessary to comply with the regulated international standards for the PAL signal (NTSC, SECAM)!

The result is an increase in the separate data and throughput of analog video surveillance systems that have become incomparable with both the analog video surveillance format PAL and high-definition standards AHD, TVI and CVI, which allow the coaxial cable to transmit a high-quality signal to a large cable.

Each of these standards has its advantages and disadvantages. However, the main advantage is that when upgrading a video surveillance system to transmit an HD video signal, you can replace the existing coaxial cables from the old analog video surveillance. All you need to do is change the camera and recorder.

AHD standard – analog signal of high clarity

The main advantage of the new AHD standard is a partial departure from the framework of the PAL standard. The physical sensor has an AHD signal identical to a standard analog signal and has the same parameters and configuration as a classic TV video signal (PTVS), in addition to the same features in the package wow signal.

In front of us, there is a frame-by-frame progressive signal, that is. In the AHD standard, additional frames are transmitted at a speed of 25 fps. The number of vertical display elements has been increased to 720 rows with 1280 points per skin. Such changes increased the frequency of the frame to 40 ms, and the upper frequency of the analogue method of transmitting a high-definition television signal reaches 16.84 MHz.

Thus, on the primary part (DVR AHD), the signal that is being captured is close in its geometric display parameters to the same digital HD signal and has the size of a full frame, equal to 1280x720 pixels.

In essence, the AHD standard is a modernized analog standard with a fixed algorithm for transmitting brightness and color signals and with fixed frequency modulation, which made it possible to transmit a signal of high clarity up to the level of FullHD 1080p without compression within the limits of transmission of a standard coaxial cable type RG-59 for a distance of up to 5 m without any troubles and expenses. In other words, with the help of AHD cameras and recorders, you can use an analog system with the power of IP systems, but without complex configuration of the system.

TVI standard from HikVision

The HD-TVI standard (or simply TVI) is a new standard in the field of analog video surveillance, and, in addition to its predecessor - the PAL standard, allows you to transmit a video signal to separate premises up to 1920x1080 pixels. HD-TVI was originally developed by Techpoint, but is often attributed to HikVision. The standard is open, so that any video surveillance provider can use the HD-TVI standard.

The main benefit of the new standard lies in the change in the technology of forming and transmitting video signals. The standard transmits an additional layer to the brightness and color signal, which allows the accumulated distortion to be eliminated to capture a clear image. HDTVI also implements an algorithm for forward processing of the video signal with further stagnation of quadrature amplitude modulation for transmission along the communication line - a 75 Ohm spindle coaxial cable.

CVI standard from Dahua

The HD-CVI standard stands for "High Definition Composite Video Interface" or "high-density composite video interface", an analog technology based on transmitting a video signal over a coaxial cable. This is a closed standard and is controlled by Dahua. Other companies may produce CVI-standard products without purchasing CVI chipsets from Dahua and may not produce them. In connection with this, it is important for them to compete on price with Dahua. Therefore, support for the CVI standard in other producers is not very broad.

Non-analog HD-SDI standard

The HD-SDI standard fails to connect analog video cable lines (coaxial cable) to transmit high-definition digital video signals.

The standard is superior to IP systems, in addition to any delays in the transmission of video signals associated with the limited transmission channel or the hours spent on video processing in the camera. This is especially true for systems with flexible PTZ cameras, where the shutdown of the image is critical in a few seconds.

The signal transmission range in HD-SDI systems depends entirely on the type of cable being used. It should be noted that, due to its nature, the signal from the camera is transmitted to the registering device without actually wasting any capacity and only if it is critically extinguished in the middle of the transmission, it simply does not reach. Tobto. either there is or there is nothing. The standard transmission ranges are RG6 -100 m and RG 59 - 50 m.

Support for AHD, TVI, CVI, HD-SDI, IP and analogue video standards

Analog video is compromised by its low price, lack of interference and great cable savings. To re-look, you can use the everyday television device. A little bit of unsatisfactory brightness can be introduced into the image.

IP systems allow you to use the existing edge infrastructure of SCS, LOM. There is no reduction in the number of megapixels. The camera can be connected directly to the global Internet. Before long, it is possible to introduce delays in the transmission of signals to the required IP-interfaces and interconnection to a maximum cable length of 90 meters in accordance with SCS standards.

HD-SDI allows you to upgrade analog video to transmit HD images via core and other cable connections based on coaxial cable. When replacing IP systems, there is no delay in signal transmission, except for interconnection along the cable and up to the cable itself, disconnections and connections.

AHD, TVI, CVI are absurd among themselves and with an analog video surveillance system, and further developments. Allows you to transmit HD images to a distance of 500 meters. The least possible cable connection is compatible with the HD-SDI standard. There is no delay during signal transmission in accordance with IP.

Low price and the Swedish throat is equal to IP systems.

Distinctions of AHD, TVI and CVI among themselves

Most HD analog equipment can operate in two modes: HD and analog mode. For example, the cameras of the AHD system can be switched to analog video surveillance mode according to the PAL standard for connection to the old recorder.

Since the AHD, TVI and CVI standards have similar meanings, I have included their main characteristics in one table.