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how to select a video monitor

Posted by fierce at 2020-04-06
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Whether you choose a video recorder to design a new video monitoring system, "start from scratch" or add it to an existing one - its type and performance will directly It depends on the structure of the video monitoring system, its tasks and the plans for future expansion and upgrading.

The main questions to be answered in selecting the Registrar are:

Please note that this article will focus on how to choose a DVD video recorder, although many times it applies to NVR) IP registers.

Technical compatibility of video recorder and camera

Modern cameras use six major video technologies (read more):

By default, not all of these technologies are compatible, so video recorders need to be selected, considering the cameras you have installed or will install.

Hybrid and trigonometric video recorder

A simpler solution is to buy a hybrid or three-stage video recorder specifically designed to interact with different technology cameras at the same time. In particular, their choice in the market is much broader than that of "single" registrars, whose choice is limited to one criterion.

The names of these registrants are hybrid DVD. R.: "hybrid" means that the registrant supports both video standards. In practice, they usually have three:

Dahua dh-hcvr5108h-s2 hybrid video recorder - 8 channels for conventional analog and hdcvi cameras, supporting 2 IP cameras.

The so-called three-level video recorder, in addition to the usual analog and IP, supports more than one high-resolution video standard, such as hdtvi and hdcvi, hdtvi and ahd.

Manufacturers don't always define "hybrid" and "tribrid," so you have to look at the performance of a particular model, which is the most common description. What video standards does the model support.

Allow video recorder

There is a common error that beginners install video monitoring system. The responsible part is to buy a high resolution camera, HD（ In this regard, no consideration has been given to the features that allow recording by the VCR, which will be connected to the VCR as this is assumed, 2. The registrar will sign the permit for camera shooting.

This is not the case. The video recorder will record the maximum resolution of the video he can. As a result, full HD video from camera to archive becomes 960h) or worse, it can't handle details.

If you are important, record the quality and details of the video in the archive (from some or all of the cameras) - you must pay attention to the DVD allowed values. Cameras from places where people only need to be seen moving can be connected to lower license registrars. For example, if the face value of the cash cashier's hand must be distinguished in the record, a camera and a video recorder with good resolution are required.

Recording speed

Registrars must be authorized with another feature - speed records, as they are interdependent. Higher resolution - lower speed, and vice versa.

Note that if the manufacturer specifies only one digital resolution - most likely the resolution with the lowest write speed.

Ideal solution - this is a 25 K / s recording on each channel, also known as real team or live video. However, these registrars are quite expensive and do not always require high recording speeds.

The selection of recording speed depends on the speed of the event in the video monitoring area. For example, in casinos, where the fraudster's behavior is enough seconds or less, it's better to record in real mode - 25 frames per second, or even higher camera. In normal facilities, you can provide a video recorder, recording from 3 to 6 frames / second, to control personnel's activity - 12K/

It is important that some manufacturers point out in their performance not the recording speed of a single camera, but a whole camera in all. That is, in fact, it will be assigned to the number of connected cameras. For example, the performance of an 8-channel video recorder indicates a recording speed of - 25 K/ This means that each camera will record at about three frames per second [25 / 8.

In some models, the total recording speed can be redistributed between chambers. For example, in the 4-channel register, at a total speed of 25 K / s, you can record at 15 K / s with one camera and the remaining three - 3 K / s.

What are the two flows?

Some camera models support two record streams. This does not mean that the Registrar writes video to disk in dual stream mode.

1） Primary, primary (main) traffic, in the best solution, is dedicated to writing registers to the hard disk.

The second - sub stream of video streams is dedicated to a stripper (view) video from a real-time camera, which usually has a higher resolution than a major one.

Number and type of hard disk of video recorder

The most common (hard disk) [or disk] video monitoring register needs to be purchased separately - it is not allowed in DVD itself. Winchester needs a professional, with a larger write resource - overlay. Because old records are always replaced with new ones, in infinite cycles, cheap hard disks will crash soon.)（

The recording space occupied by the video recorder must be calculated in advance. Not all registrants can operate large capacity disks, usually only 4-6 disks, not all people support connecting more than 1 disk - this is also a choice to consider.

Another point is to consider the compatibility of different brands of hard disks and DVDs. Manufacturers regularly publish recommended Winchester tables for their video registrars.

Interface - what can I connect to a video monitor

Channel number

The number of channels in the video recorder is the number of analog cameras that can be connected to it). Each camera is connected to a separate video input) BNC interface.

If DVD supports IP camera connection, it is usually not included in the specified number of register channels. How many IP cameras support registers are specified separately in the feature and connected to the register interface through a LAN. That is, if you specify a mixed 8-channel register, you can connect to 8 analog cameras, and how much IP - you need to see the performance.

When choosing video recorder, we need to consider the expansion plan of future camera network. It's better to have a register with the number of spare channels - the price difference won't be that big, but when the network grows, you don't need to buy extra registers.

Audio and audio output) (RCA)

The channel is designed to connect the voice recorder to a separately mounted microphone. In most cases, the registrar has either one audio channel, multiple camera channels, or none at all. This is all familiar with RCA connectors, for connector tulips. "

In Ukraine, sound recording on site is severely restricted by law, so in organizing audio recording of video monitoring, it is necessary to ensure You won't have trouble with the authorities.

You can connect to an audio output column or other audio playback device.

Warning inlet outlet) (RS-485)

Different sensors - motion, break and other. Therefore, for the events recorded by these sensors, the Registrar can adjust various actions of the system: at least start recording the video into the file.

Rotating PTZ camera connection

There is also a remote control camera connected to the RS-485 connector. This camera is also known as a PTZ, speed dome or robot camera. You can switch to a specific direction remotely - manually or automatically.

Connection Monitor

It depends on the video monitor you are going to extract from the camera, and you have to determine what slot to set in the register. The videotape is connected to the registry and has been connected to a monitor for real-time viewing of the video of the observed objects.

The TV monitor is connected through the BNC interface - just like the video input in the analog camera.

Standard connection of computer monitor to VGA interface, if you want to connect to high resolution monitor):) Full HD) - select a video recorder to disconnect from HDMI.

Most popular register models have three types of video output - BNC, VGA, HDMI.

Additional characteristics of registers

Video compression format

Almost all modern registrars use compressed H.264（ The weight of video file and the volume of video stream are relatively small. Previous formats (MJPEG), previous versions of MPEG4, etc. Video of fast moving objects.

Motion detector

Very useful features. Its essence is that when an observed object moves, media recording begins. The rest of the time, when the picture is still, the DVD doesn't write anything. The motion recording function allows:

Many models also allow a small piece to be written down a few seconds before the movement takes place.

In addition, the motion detector can be configured to a certain observation point, rather than the angle of the whole camera: door, window, etc. P.

Network protocol

Almost all modern video monitoring register models can be connected to LAN. Even if it's not a network (NVR) or hybrid video recorder, it's a regular DVD. If its characteristic is to list a network protocol, it means that it can be accessed through the Internet or LAN. Depending on the model, the video recorder can be remotely:

Multitasking)

The video recorder can also perform different tasks at the same time. Depending on the organization of the video monitoring system, you can buy DVDs:

Achievements

Therefore, the most important parameters in the selection of video recorder are:

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