home Programs Dvr cameras what. HD DVR - a high-resolution device

Dvr cameras what. HD DVR - a high-resolution device

DVRs have recently become often used as an elemental component of a video surveillance system or as a stand-alone device. As an individual device, recording equipment is installed in vehicles. This car gadget performs video recording of events occurring while driving and while the car is in the parking lot. Video monitoring lines use a DVR. The abbreviation DVR means the characteristics of the device itself (Digital Video Recorder) and indicates that the device is digital. Recording equipment is used to receive video signals from analog video cameras and subsequently digitize them.

The DVR video recorder is equipped with video monitoring systems that are classified as professional.

Video surveillance lines equipped with devices of this type are installed in office premises, shops, factories, warehouses, as well as in shopping and entertainment establishments. Operating these devices does not require special knowledge or skills. As a rule, the latest models are improved, have a clear interface and are easy to set up and operate. The information that is processed by the DVR is recorded on a hard drive. You can view the video image via a personal computer or TV, as well as via the global network, i.e. remotely.

What types of Digital Video Recorder recording equipment are there?

In order for the user to understand what is the best DVR video recorder to equip a video surveillance system, you need to know that there are two main types of such devices:

PC-based;
Stand Alone.

The DVR recorder, which is of the PC-based type, operates on a personal computer. The main mechanism is the video capture card. The operation of a computerized recorder is ensured by using special software. Such devices have a convenient and intuitive interface. The disadvantage of using such equipment is the inability to use the serving computer for other user purposes (for example, watching movies or playing games).

Stand-Alone video recording devices use specialized software and certain hardware modules. As practice shows, many users prefer just such DVRs. These devices are distinguished by reliable and efficient operation, as well as simple operation. They have a reasonable price. For full-scale operation, in addition to the video recording device, the purchase of a hard drive is required.

Main technical parameters of video recording devices Digital Video Recorder

The main technical parameter of video recording equipment such as Digital Video Recorder is the number of channels. Channel indicates the maximum number of connected video cameras. Today there are the following number of channels in video recording devices:

One;
Four;
Eight;
Nine;
Sixteen;
Thirty two.

Basically, devices with 4, 8 and 16 channels are in great demand. Typically, a BNC connector is used to connect video cameras. A necessary parameter of a video recording device is the number of audio outputs. With their help, audio recordings of ongoing events are performed. As practice shows, the number of microphone connectors does not exceed the number of video inputs. The number of frames during recording is a characteristic that determines the speed of video recording. The optimal value is 25 frames (based on one second). Modern models also have a higher recording speed.

High-speed mode, with at least 25 frames, allows you to shoot and playback video information in real time (in the current mode).

Another important parameter is resolution. Today, manufacturers offer HD DVRs. In this case, the HD marking reflects the acceptable resolution. Also quite common are the D1, D1/2, CIF and 2CIF formats. The higher the resolution, the clearer the image received by the video camera will be transmitted. With increasing resolution, the use of compression codecs was required, since high-quality information takes up more space on the hard drive. Modern video recording devices use the H. 264 compression codec. Earlier models used MPEG4 and MJEPEG codecs.

In the video – DVR video recorder:

Types of connectors in Digital Video Recorders

Depending on the selected model of recording equipment, several control monitors can be connected to the video surveillance system in parallel. Basically, all models use one video and one audio output. Regardless of the assembly of the selected recording device, the device is equipped with the following connectors:

RJ 45 (or modifications of slots such as TCP/IP, DDNS, DHCP, DDNC);

The VGA slot characterizes the ability to connect a video recording device to the monitor. This connector connects the display of a standard personal computer. Almost all modern models are equipped with such a connector. The HDD slot allows you to connect a removable hard drive (hard drive) to the DVR. This connector, depending on the storage capacity of the drive and the number of mechanisms, may be different. Basically, SATA and IDE slots are used as an addition. The SATA format has recently taken a leading position and is displacing its predecessors.

A review of modern models shows that video recording devices with HDD and IDE slots are practically not produced.

Network slots such as TCP/IP, DDNS, DHCP, DDNC indicate the ability to connect video recording equipment to a global or local network. Using these connectors, you can make a network connection and control the device, including the video surveillance system as a whole, remotely. Along with slots, users pay attention to the type of recording device itself. Currently, there are equipment that is duplex, triplex or pentaplex. This parameter characterizes the device’s ability to perform several tasks (options) simultaneously. It is best to use devices with a pentaplex type due to the fact that the recorder can perform five functions in parallel. For example, you can record, view, play back video information, as well as remotely manage and backup it.

The video shows a review of the DVR:

How to control Digital Video Recorder devices?

Video recording devices of the Digital Video Recorder type are controlled in the following ways:

Using infrared remote control;
Via control keys;
By using a computer manipulator (mouse);
Network method based on specialized software.

The most convenient way to control is to use a regular computer mouse. Although all types of control are found in different models of video recording devices. Also, a special detachable USB slot is used to carry out management actions. Using this connector, you can archive recorded video information. The recorder can be directly connected to a computer or removable storage device of various sizes. Often in practice, users use this type of slot to update the firmware and software version of the video recording device. To connect security sensors and actuators, as well as to control them, special alarm inputs and outputs are provided.

The best model of a high-quality car gadget in Digital Video Recorder format

As already mentioned, Digital Video Recorders are used as stand-alone car gadgets. A novelty in the modern world of electronic technology is the HD DVR. The assembly model DVR-027 has become widely used. This device can record video events in high quality and has HD resolution (1280x720 pixels). The quality of video recording is quite high at different lighting levels.

This car video recording device is quite compact and is considered portable.

The video shows an example of shooting with a DVR:

There is a built-in infrared illumination, which has six LEDs. The six-LED backlight ensures almost perfect video recording at night. All video files are stored on a removable storage device. The maximum device capacity is 32 GB. The footage can be viewed on the built-in display or on a personal computer. In this case, it is not necessary to connect the video recording device via a connecting cable; for these purposes, using a card reader is quite acceptable. The viewing angle is 120°. The recording speed is 30 frames. If necessary, video recording can be slowed down to 10 frames per second.

HD DVRs define the maximum resolution. At the user's request, the resolution can be changed to 848x480 or 640x480 pixels. The device records information in cyclic mode. The display is rotatable and can change the viewing angle by 270°. The recording format is AVI.

Hello. Review of a car recorder sold for a ridiculous $11.50. Which is what sparked my interest. While the product was on sale and the review was being written, the discount ended. But most likely she will appear again. On Ali, a similar recorder is sold for . So what do we get for this price?

There were two colors to choose from.

Despite the super budget, there is a box no worse than that of its expensive relatives

Equipment. A three-meter charger (I always plug this one into the socket in the trunk, run the wire along the top, braiding the handles, then behind the sun visor and that’s it), a data cable and a suction cup. I think these bells and whistles are already half the price.

And here is the comcoder itself.

The “pop-eyed” lens is striking. The front lens protrudes outward and it is impossible not to hit it. Therefore, here you need to be careful and not place the device on the lens. Despite the pop-eyed look, this is not a fish-eye. The viewing angle is 110 degrees horizontally, which corresponds to 24 mm EGF for film cameras. That is, according to the generally accepted classification, this is an ultra-wide-angle lens. On the right you can see the backlight LED, a regular one, not infrared. Turns on and off by briefly pressing the “on” key. It is useless for the needs of a car recorder. It might be useful to highlight something under your feet on the rug when there is nothing better at hand.

On the left are mini USB connectors, audio video output (input?). But here you won’t be able to connect straight away to a 2.5 mm jack. (I’ll go into the bins to look for vintage headsets with such a connector). HDMI with limited functionality - when connected, the reg is forced into playback mode.

On the right is a slot for micro SD and a power key, which also turns on the LED, and a key for switching modes - video, photo, viewing.

On top there is a socket for a quick-release mount, which is a groove in which the recorder is held by friction force quite reliably due to the lightness of the subject, about 50 g

Well, at the back there is a 2.4" display, at the bottom of the display there are keys with characteristic symbols that do not need to be explained. True, a couple of keys have 2 functions. When shooting a video, pressing the key with the triangle pointing up turns off the microphone, pressing the key with an exclamation mark (menu ) blocks the file from being overwritten.
The red button in the center turns on the parking mode. In this mode, when shaking (the strength of which can be set in the corresponding menu item), the turned off recorder turns on and starts video recording, protected from erasure.

When connecting to a computer, the subject offers you to choose from two options - card reader mode and USB camera. The card reader is quite fast, reads from a class 10 card at a speed of 30 MB/sec. As a USB camera, the recorder is also not bad, it provides an image without interference in low light, and the wide-angle lens allows you to shoot a person waist-deep from 70 cm. When installing a USB camera, a USB audio driver is also installed. That is, the sound must come through the built-in microphone of the recorder. But I couldn’t do this using the existing utilities.

Characteristics of the video file.

Format: AVI
Format/Info: Audio Video Interleave
File size: 124 MiB
Duration: 1mn 0s
Overall bit rate: 17.4 Mbps
Director: Generalplus
Original source form/Distri: Generplus
Recorded date: 2010-06-29
Copyright: Generalplus

Video
ID: 0
Format: JPEG
Codec ID: MJPG
Duration: 1mn 0s
Bit rate: 16.8 Mbps
Width: 1,280 pixels
Height: 720 pixels
Display aspect ratio: 16:9
Frame rate: 30,000 fps
Color space: YUV
Chroma subsampling: 4:2:0
Bit depth: 8 bits
Compression mode: Lossy
Bits/(Pixel*Frame): 0.606
Stream size: 120 MiB (97%)
To compress video, MJPEG (Motion JPEG) is a frame-by-frame video compression method. It’s easier to say ordinary serial photography, each frame of the video is a photo in jpeg format. The disadvantages of MJPEG are its lower compression ratio compared to streaming methods. And the advantage is that it does not require high processor performance, it is easy to install. And what is rarely mentioned is that you can get fairly high-quality still frames, which is important for a video surveillance device.

The registrar has an extensive menu, surprisingly all the items work.

Based on the settings, I will say that the default G sensor mode set to 4G is overly sensitive. In this case, a third of my files turned out to be blocked from erasing, although not without reason - where I jumped over a policeman, where I suddenly braked, like here for example (I remind you that the lens is wide-angle and objects are removed 2 times compared to reality)

Characteristics

ype: Full HD Dashcam,HD Car DVR Recorder
Chipset Name: Generalplus
Chipset: Generalplus1248
Storage
Max External Card Supported: TF 32G (not included)
Class Rating Requirements: Class 10 or Above
Display
Screen size: 2.4inch
Screen type: TFT
Power
Battery Type: Built-in
Charge way: Car charger
Battery Charging Time: 2 -3 hours
Primary Info.
Wide Angle: 110 degree wide angle lens
Camera Pixel: 3.0MP
ISO: Auto,ISO100,ISO200
Video/Image/Audio
Decode Format: MJPEG
Video format: AVI
Video Resolution: 1080P (1920 x 1080),1440 x 1080,720P (1280 x 720),848 x 480,VGA (640 x 480)
Video Frame Rate: 30fps
Video Output: AV-Out,HDMI
Image Format: JPEG
Image resolution: 12M (4032 x 3024),5M (2592 x 1944),8M (3264 x 2448)
Audio System: Built-in microphone/speaker (AAC)
Exposure Compensation: +1,+1/3,+2,+4/3,+5/3,-1,-1/3,-2,-2/3,-4/3,-5/3, 2/3
White Balance Mode: Auto
Functions
Loop-cycle Recording: Yes
Loop-cycle Recording Time: 10min,1min,2min,3min,5min,OFF
Motion Detection: Yes
Night vision: Yes
G-sensor: Yes
HDMI Output: Yes
Delay Shutdown: Yes
Time Stamp: Yes
Interface Type: AV-Out,Micro USB,Mini HDMI,TF Card Slot
Language: English,French,Italian,Japanese,Korean,Portuguese,Russian,Simplified Chinese,Spanish,Traditional Chinese
Other
Apply To Car Brand: Universal
Dimension/Weight
Product weight: 0.050 kg
Package weight: 0.254 kg
Product size (L x W x H): 7.00 x 6.50 x 4.00 cm / 2.76 x 2.56 x 1.57 inches
Package size (L x W x H): 16.00 x 12.00 x 8.50 cm / 6.3 x 4.72 x 3.35 inches
Package Contents
Package Contents: 1 x GT300 1080P Car Dashcam DVR, 1 x Car Charger (Cable Length 345cm), 1 x Bracket, 1 x USB Cable (42cm)

This recorder is not my first, or even my twentieth. At one time I was interested in them - I bought them, used them, sold them. Therefore, I was immediately skeptical about the stated characteristics of the subject for such a price.
The physical size of the matrix in this recorder is apparently about 1 MP, therefore there cannot be any Full HD here, especially 12 MP photos. And indeed there is no difference between Full HD and HD, between the set photo resolution of 8 MP and 1.3 MP. This is just interpolation. In short, I had no illusions about the permission; what I expected was what I got.
But the untuned lens was a little disappointing. The image is blurry. Again, I treated this condescendingly. here the guys on the Xiaomi action cameras are turning the lenses, and here is some kind of non-name, God himself ordered it.

At this point, doubts about whether to disassemble or not to disassemble completely disappeared. The recorder was immediately disassembled to adjust the lens. The subject is easily disassembled, 4 screws are unscrewed and the front panel is removed.

Here we see a small battery with a small capacity, which is only enough here to save a file when the external power is turned off. The recorder works in offline mode for 4-5 minutes and turns off. Whether this is intended or the battery is defective is unclear.
The chamber module is mounted on hot-melt adhesive (savings in everything), although there are holes for screws for fastening. The lens is fixed with a transparent resin-like substance, so to start turning it you need to break the fixation with a sharp but short movement of the pliers. Sharpness was adjusted in USB camera mode. Of course, it would be better via HDMI, but when connected via HDMI, the recorder goes into playback mode.
At the same time I looked at the processor

It looks like this. Interesting information was received from EXIF - the camera module is designated Maginon CBB3. A recorder from the German company Supra was produced under this brand. Along the way, the firmware was stolen from there.
Well, now let’s move on to the quality of shooting
I'm posting a couple of photos of still frames from the video.

The video file can be downloaded

The codec is gluttonous - 10 minutes requires 1 GB. But there is a function to protect files from overwriting. You can always block the file you need and don’t worry about it getting lost. Number plates can be distinguished mainly from passing cars, and extremely rarely from oncoming cars. Of course, the lens here is too wide-angle for the resolution of the matrix, so it receives more information than it can digest. If there had been a longer lens, the situation with identifying license plates would have been better.
The microphone is quite sensitive and sound recording works both when the engine is off and when driving. What I mean is that many recorders suffer from poor sound recording; when driving, you can only hear a crackling sound.
Neither the recorder nor the power supply interferes with the radio.

The holder has a short lever, and the recorder itself is light, so there is no shaking.

But there is a drawback common to all suction cups - the recorder lens is too far from the glass and raindrops, insects, etc. end up in the DOF zone (depth of field).

The image quality in this recorder is quite acceptable in my opinion. The numbers are of course hard to distinguish. But they are also hard to see on real FULL HD. Because here it’s not a matter of resolution, but of endurance. To photograph an object clearly moving at a speed of 120 km/h at a distance of 30 m, you need a shutter speed of 1\250 sec; the coolest FPS recorders have a maximum of 120 per sec. that is, they film the numbers with blur, but acceptable, allowing them to be made out.
Therefore, I believe that the numbers are not the main thing, because in addition to emergency situations, the recorder records all sorts of road oddities, which are interesting to look at later.
For example, this is the jack-in-the-box. It scared me, I was just about to pass a little to the left.

Today I got hold of a 2.5mm mini jack. Connected the recorder to the monitor. It conveys the picture well.

You can use the subject part-time as an overtaking camera on right-hand drive cars. Well, the question remains with connecting the rear view camera. Here you need a jack with 4 pins to switch input and output. I'm planning to buy +15 Add to favorites I liked the review +22 +32

The Xiaomi mijia Car DVR Camera blew up the market with its appearance. Stylish design, excellent technical characteristics, brand, and the device is already very popular at the start of sales. I decided to do a review because I am a direct user of this device and am ready to form a full review. Examples of shooting from the recorder and ease of use await you below.

Xiaomi mijia Car has become the second car recorder of the Chinese brand. In 2016, the company released Xiaomi Yi 1080P Car WiFi DVR. Technically, the devices are very similar, but a number of small differences still exist. A comparison of these two recorders will be below, but for now let’s continue the review of Xiaomi mijia Car DVR Camera.

Equipment

The Xiaomi mijia Car DVR Camera comes with everything you need, namely:

Registrar
USB cable 3.5 meters
Charging 12V
Holder
Additional sticker on the holder
Glass sticker for safe installation of the holder – 2 pieces
Tool for laying cables under car trim
Instructions

MicroSD card is not included. Device supports memory cards of at least class 10 and up to 64 GB.

Design

The first thing that catches your eye is the design of the recorder. The device looks expensive and is made of high quality plastic. In Russian realities, you should worry about how visible the device is from outside the car. It must be removed if you plan to park for a long time. The fastening mechanism is very smooth and convenient, the recorder is easy to remove and put on the holder. Before ordering I was very worried that there would be problems with this, but everything turned out to be more than thought out.

Overall design rating: 10 of 10. I really liked it.

Specifications

The characteristics of the Xiaomi mijia Car DVR Camera give an idea of the recording quality of this recorder. It has everything you need except GPS. Yes, this option is missing, although many fans of the company were waiting for it. From personal experience I will say that I never used GPS on my previous recorder. But the thing is still useful and would definitely not be superfluous, especially in controversial moments on the road. But its absence affected the price of the device, making it as affordable and budget-friendly as possible.

Xiaomi mijia Car has a Sony IMX323 CMOS sensor, which allows you to record video with 1080P 30fps or 720P 60fps(the recorder itself records only with a frame rate of 29.9 fps, perhaps the functionality will be expanded in the future). Clarity and noise reduction are achieved due to the large F/1.8 aperture, which allows you to shoot with a “readable” picture even in low light conditions. Video compression is performed in accordance with the H.264 standard. MP4 recording format. The recorder is equipped with a Wi-Fi module, with which you can view recordings on a smartphone and update the firmware.

Specifications of Xiaomi Mijia DVR

Display 2.7″, resolution 426×240 px
Sony IMX323 CMOS sensor
Viewing angle 160 degrees
Processor MSC8328P
H.264 compression format
Video 1080P 30fps / 720P 60fps
Aperture F/1.8
Synchronized audio recording
Loop video recording
Wi-Fi, G-sensor, ADAS
Battery: 240 mAh
Dimensions 8.80 x 5.30 x 2.80 cm

Ease of use

Xiaomi mijia Car DVR Camera is very easy to use. There are minimal settings on the device, set it once and forget it. The only negative point that you will have to face is the Chinese interface language. But I don't think this is a problem. For convenience, I have attached a translation of the registrar settings into Russian. I also found the touch buttons used to navigate the device inconvenient.

You can connect to the car recorder via a smartphone. It's comfortable. You can now watch videos quickly, without getting into the wilds of Xiaomi mijia Car. The iPhone connected to the device without problems, but nothing worked with Motorola on Android 6.0, obviously, “dancing with a tambourine” could have helped, but I didn’t bother to figure it out.

By the way, for mijia to work with a smartphone, you need to install the proprietary Mi Home application on the latter. You can download the Russian version of the plugin for the application. Let's move the review from theory to practice and look at examples of videos that the recorder shoots.

Examples of videos shot on Xiaomi mijia Car DVR Camera

Shooting in clear weather on the highway

Overcast

Shooting at night (twilight)

Download all video files, in original quality available on the Cloud. This is the only way you can see an example of recording a recorder without compression.

Comparison of Xiaomi mijia Car DVR Camera with Xiaomi Yi 1080P Car WiFi DVR

Firmware

Xiaomi mijia Car came to me with firmware version 1.0.6, and after the first connection to the smartphone, it offered to update to 1.0.8. The update took about 8 minutes. From the reviews on the Internet, it became clear that the recorder began to shoot more consistently, the picture became clearer, and the “soap” went away. Later firmware 1.0.9 was released. with minor GUI related changes. From the experience with the Yi 1080P Car, it is clear that the developers will eventually release optimal firmware that will allow the hardware to reveal its full potential. Global firmware in English will most likely be available in the summer of 2017.

Review of Xiaomi mijia Car DVR Camera. Is it worth taking?

Result: After a month of daily use, only positive emotions remained. The device behaves stably. Installation into the holder is very simple and quick. A good 160-degree view gives an informative picture “from rack to rack.” I’m a little unhappy with the night photography, very often the car license plates are simply illuminated and unreadable, I hope that with the release of the new firmware this shortcoming will be corrected.

During the day, in most cases, you can use a freeze frame to catch the license plate of an oncoming car without any problems, but the picture as a whole is overexposed, and the recorder catches a lot of glare. This drawback can be eliminated by installing a polarizing CPL filter. The lens diameter is 40.7 mm, you can use a 40.5 mm polarizer, but then the edges of the frame will be blocked, not critical, but if you want to get rid of them, take a 46 mm filter with an adapter ring from 42 mm.

It is very interesting how the recorder will behave in the summer, whether it will warm up. I will definitely add to the review after testing at high temperatures, I hope there will be such things often! I’m ready to forgive the registrar for the Chinese language, and I’m also sure that global firmware in English will soon be released, and everything will be even simpler. For a price of 3000-4000 rubles, Xiaomi mijia Car DVR Camera is a leader and films like a device for 8000 rubles over.

Where can I buy

Aliexpress(Mi Tech Store)	Link
Aliexpress(Xiaomi MC Store)	Link
Banggood	Link
Gearbest	Link

CCTV cameras are available at reasonable prices and keep you safe both at home and in business. Each of us can afford to protect ourselves from vandalism, theft, and also increase the overall productivity and efficiency of workers through the use of a professional video surveillance system.

Standalone DVR security cameras are all-in-one units. It's all the components built together that matter. DVR video cameras are digital video cameras, the distinctive features of which are high reliability and ease of use and installation. In appearance, they are very similar to VCRs or DVD players. With the development of technology, including video surveillance technology, DVRs are quickly replacing old, outdated VCRs. For example, when using VCRs to record movies, VCR tapes will lose their quality over time, but since camcorders are digital, the quality of the image and video will be constant.

Digital video cameras are becoming very popular for video surveillance systems, especially for home, office or perimeter security, where they are very easy to install and configure, making them effective and smart to purchase. An additional advantage of CCTV cameras is that the recording is made to some storage device, such as a hard drive. This will save you from the hassle of storing video recordings. In addition, no additional tools such as cassettes are required. DVR cameras are designed to work 24/7, and after the hard drive is full, the DVR deletes the oldest recording and starts filling the hard drive from the beginning. This means you'll save a fair amount of money on storage and storage space. The DVR camera system provides instant access to recorded videos, as well as real-time access and control.

Standalone DVR CCTV cameras are highly reliable and user-friendly. Mainly because they are designed for one task, which is to record, store and playback videos. So you don't need to worry about system crashes or software conflicts because all the hardware and software are built into one board.

If simplicity, reliability and stability are important to you, then DVR video cameras will be the best choice.

Available in our store wide range of video cameras. We sell and install video surveillance systems. You can view the products at

In this article we will try to popularly explain what it is DVR. The abbreviation DVR is Digital Video Recorder or digital video recorder in Russian, that is, a device designed to record video in digital format.

Now we’ll tell you in more detail about what types of DVRs there are, what characteristics they have, how they differ, and what these or other symbols mean.

First of all, let’s define 2 types of DVR:

PC-based DVR
Stand Alone DVR

PC-based DVR– these are the so-called “computer video recorders”. That is, systems consisting of special Software (hereinafter referred to as Software), a video capture card and a computer. Such systems have the following advantages:

user-friendliness of the interface;
possibility of extension;
flexibility of configuration and customization.

But PC-based DVR There are also some disadvantages:

dependence on the reliability of the computer and its operating system (most often Windows);
the possibility of dual use of a computer (which is extremely undesirable in video surveillance systems);
difficulty of installation and configuration for an untrained user;
big sizes.

Stand Alone DVR(namely, Stand-Alone DVRs have come into our use as simply DVRs, which is why we will call them DVRs) are specialized video recorders, devices specifically designed for video surveillance needs. They use specialized hardware and software.

DVR advantages:

high reliability,
ease of operation,
small sizes.

Disadvantages of DVR:

impossibility of extension (upgrade).

So, what are the characteristics of DVR and what do they mean?

DVR video inputs

Typically, DVRs have 4, 8/9 and 16 video inputs; occasionally there are 6, 12, 24 and 32-channel DVRs, but devices with such a number of video inputs are the exception rather than the rule.

DVR audio inputs

They are also often found in DVRs. They allow synchronous audio recording. The number of audio channels ranges from 1 (as in BestDVR-401Light-S) to all 16 (as in BestDVR-1602Real-S).

DVR video outputs

There are several options here. The simplest DVRs have 1 BNC video output. More complex ones - several and in different formats - such as: BNC, S-VIDEO, VGA, DVI, HDMI. At the moment, the most popular video outputs are BNC and VGA; they allow you to display images on regular and computer monitors. There are 2 main approaches to using these video outputs:
1 – switchable video output (that is, only 1 works at a time), for example, video output is implemented in BestDVR-401Light-S, BestDVR-800, BestDVR-1600.
2 – synchronous operation of video outputs, when the image is duplicated on both monitors, this is how BestDVR-403LightNET-S and BestDVR-903LightNET-S are designed.

Often, in addition to the main video output, the DVR has additional ones (most often these are BNC video outputs) they are used to display in full screen the “alarm” camera in which movement has currently occurred and are called SPOT outputs. Such outputs are available, for example, in BestDVR-1602A-S. For more serious DVRs, the additional video output has wider capabilities and is already called MATRIX video output, for example, with BestDVR-1602Real-S and BestDVR-1600Turbo-S, you can display an independent multi-screen on this video output and even watch an archive on it. The greatest potential at the moment is the HDMI video output, which will allow you to connect a FULL-HD monitor and get the highest quality images.

DVR compression algorithm

DVRs always use compression for video recording (since without compression, the disks would fill up very quickly, and transmitting video over the network would not be possible). There are many compression algorithms, we will list them from top to bottom with their advantages and disadvantages. Let us immediately note that they are divided into 2 types - frame-by-frame and streaming. Frame-by-frame compresses each frame, while streaming compresses the video stream. Streaming algorithms compress several times more efficiently than frame-by-frame algorithms. Single-frame ones give a slightly clearer picture during playback.

MJPEG– the oldest and cheapest frame-by-frame algorithm to develop, low compression ratio.

JPEG-2000– modern “reincarnation” of MJPEG. Rarely used.

Wavelet– a frame-by-frame algorithm popular in its time, compressing more efficiently than JPEG but not as efficient as streaming algorithms.

MPEG-2– a streaming algorithm that gives high quality video (it is used for recording DVDs).

MPEG-4– the most popular video compression algorithm today (3 times more efficient than MJPEG). It is this compression algorithm that is used in BestDVR Econom-class recorders.

H.264(MPEG-4) is the most progressive and promising (but difficult to develop) streaming algorithm today, combines high video quality (it is used for HD-TV television broadcasting) and strong compression (one third more efficient than standard MPEG-4 ). It is this algorithm that is used in the BestDVR Professional class and BestDVR HI-END class recorders.

Resolution and recording speed (for PAL standard)

These are perhaps the most important characteristics of any DVR; they actually indicate what quality of video recording you will receive. All of these resolutions are limited to the PAL standard.

There are several standard resolutions, let's consider from the highest to the lowest: 720 * 576 pixels - D1 or 4CIF– the highest resolution, otherwise called “full frame”, is used to obtain the highest quality recording.

528*384 points – DCIF– intermediate resolution.

720*288 – HalfD1 or 2CIF– half-frame or “field” (since a PAL format frame consists of two fields), this is a fairly high resolution, which often turns out to be the golden mean between recording clarity, frame size and cost of the system as a whole.

360*288 – CIF– quarter frame – a resolution that gives a rather rough picture, but saves disk space and allows you to save traffic when transmitting video over the network.

180*144 – QCIF- a resolution that gives a terrible picture, but allows you to greatly save network traffic, for example, for H.264 compression, the stream from one camera at a speed of 25 fps at this resolution will be only 128 Kbit.

By the way, in hybrid DVRs that can simultaneously record signals from analog and network cameras (for example, in the BestDVR-1608IP model), it is possible to record signals from IP cameras with HD resolution 1280*720 pixels at a speed of 25 fps.

DVR recording speeds

Abbreviations that are widely used in the industry:

k/sec– frames per second
fps– frames per second - translated “frames per second” or can mean field per second, in Russian fields per second
ips– images per second – translated “images per second”
pps– pictures per second – translates to “pictures per second”

In fact, all these abbreviations mean the same thing; it’s just that some try to indicate the speed in “fps” for “full frame” (720*576) resolution, and in ips or pps for “quarter frame” (360*288). But most always indicate "fps", and for accuracy the resolution is also indicated. By the way, you need to be careful, since some manufacturers indicate in the characteristics of their DVR the maximum overall recording speed and do not indicate that it is provided at the minimum resolution.

Recording speeds for the PAL standard are limited to an upper value of 25fps. Resolution and recording speed should always be considered in conjunction with each other and the object that will be recorded. For example, a recording of a walking person recorded at a speed of 25fps and CIF resolution will be much less informative than with D1 resolution and a speed of 3-4 fps.

House, office, cottage small shop 3-6fps/2CIF
Gas station, warehouse, parking, market 6-8fps/2CIF
Supermarket, bank, 12fps/D1 port
Subway, shopping center, train station, airport 25fps/D1
Casino, jewelry store 12-25fps/HD(1280*720)

DVR Control

There are 4 common control types for DVR:

The most advanced DVRs usually offer users all of these features. For example, all Real series DVRs have buttons on the front panel, are equipped with IR remote controls and mice, and additional keyboards are available as an option.

Discs used in DVR

Modern DVRs typically use standard computer hard drives for recording. Although, it is worth noting that some drive manufacturers, such as Seagate, have responded to the needs of the video surveillance industry and have developed specialized drives with increased reliability. Most often these are 3.5" drives (2.5" drives are more often used for mobile DVRs) and with an IDE or SATA interface. Typically, a DVR can accommodate between 1 and 8 discs. By the way, you need to take into account that drives with an IDE interface are practically no longer produced, since most manufacturers have switched to producing faster and more reliable SATA drives, so if the DVR only has an IDE interface, then to connect a SATA drive you will need a SATA-IDE converter. It should be noted that most BestDVR models already support SATA drives, this is indicated by the letter S in the names of the devices

By the way, when purchasing disks for DVR, you should make sure which brands are recommended for a particular device, and what maximum volume your DVR supports.

Interfaces for DVR

What interfaces do DVRs have and what are they used for? First of all, this is USB - this interface is used for archiving. An option is possible when DVRs are directly connected to a PC via USB, for example, this is how this interface is configured in BestDVR-401Light-S, or you can connect USB-flash, USB-HDD, USB-DVD-RW devices to the USB port and archive recordings on them, such as BestDVR-402A-S, BestDVR-802-S. Also, the USB port is often used to update the recorder software.

Sometimes the DVR has a Compact Flash connector, which is also used for archiving and updating software.

RS-485 – this interface is intended for control. It can also be used to connect a keyboard to control the DVR. Or to control PTZ cameras from the recorder.

RS-232 is an engineering port for DVR diagnostics and programming.

Alarm inputs and outputs – used to connect security sensors and actuators (sirens, flashers, etc.).

DVR network functions

DVR network features are becoming more and more relevant, so it is important to understand what each feature means. First of all, network functions imply several possibilities:

real-time video broadcast;
audio broadcast;
viewing the archive;
archiving (copying recordings from DVR to PC);
setting.

Typically, a high-end DVR supports all these functions, for example, all network BestDVRs of the Professional and HI-END classes have all this functionality.

Types of network software:

Client software – allows you to simultaneously connect to one DVR, example – BestDVR-403LightNET-S, BestDVR-903LightNET-S.
CMS (Central Monitoring Station) software – allows you to simultaneously connect to several DVRs, example BestDVR-802-S, BestDVR-1602A-S.
WEB-server – the ability to access the DVR from a WEB browser window (without installing additional software).
Dual Stream technology is a very important technology for network work, allowing you to set independent quality settings for each channel for recording and broadcasting to the network. Dual Stream allows you to record with maximum quality and broadcast to the network with minimal traffic consumption.

Multitasking DVR

The DVR has several types of multitasking. Let's talk about each of them.

Simplex– simultaneous execution of one operation (when viewing the archive starts, recording stops).
Duplex– the ability to view the archive without stopping recording.
Triplex– 3 operations at the same time - broadcasting, viewing the archive and working on the network simultaneously.
Pentaplex– 5 or more operations simultaneously (recording, local monitoring on one monitor, viewing an archive on another monitor, archiving and network work).

Motion detector in DVR

Motion detection is a very important function in a DVR; in addition to saving disk space by recording only those frames that contain motion, it also saves the user’s time for further searching in the archive. A motion detector is usually characterized by two characteristics:

There are also additional characteristics of the motion detector, but they add more complexity than efficiency. In essence, everything is simple here - the higher the accuracy of the detector mask and the more sensitivity levels, the better.

Other Common Terms

Relatively recently, so-called “hybrid DVRs” began to appear on the market - devices capable of recording signals simultaneously from analog and IP cameras. The advantage of these devices is that IP cameras do not have a resolution limit of 720*576 pixels, and the image can be obtained several times clearer. For example, BestDVR-1608IP can record a signal from 8 IP cameras with a resolution of 1280*720 and a speed of 25fps (or from 16 IP cameras with a resolution of 720*576 and a speed of 25fps).

Conclusion

As you can see, DVR is simple. There are not many terms and characteristics, and if you understand them at least a little, you can choose the optimal device to solve your problems. And the further effectiveness of working with it depends on carefully reading the instructions, following the rules of use and quality support from the manufacturer.