Car cam

In different countries, the use of car DVRs by private individuals is considered differently: in some countries it is allowed without restrictions, but in other countries the use of car DVRs by private individuals may be outlawed, since DVRs can be considered tacit devices that violate the rights of others persons to privacy , and allowed to be used only by government agencies that are granted by law the right to activity.

Russia

The data recorded by the DVR, according to the Code of Administrative Offenses, can be considered as evidence in the proceedings of an administrative violation case ^[1] . The decision on whether to add to the administrative case the testimony of the registrar is made by the judge . A bill is under consideration in the State Duma , according to which the court will be required to take into account the data of recording devices in proceedings ^[2] .

Austria

The Data Protection Commission under the Austrian Federal Government has banned the use of car DVRs, considering their use an interference with privacy, as people’s faces and car registration marks may be recorded. If the unauthorized installation of the DVR is detected, a fine of 10,000 € is imposed , with a re-installation, a fine of 25,000 € ^[3] .

Germany

The courts do not decide unambiguously on the admissibility of using the DVR as evidence. So the district court of Munich in one case allowed to attach the filming to the case ^[4] , and in the other banned ^[5] .

USA

The use of DVRs is allowed only to the police and other special vehicles, regardless of state.

Ukraine

Ukrainian legislation in this regard is not much different from Russian.

Security video systems

Some car DVRs can be used as a CCTV camera in a parked car or as a security video camera indoors. Many registrars have special “parking” modes (photographing moving objects that fall into the field of view of the device).

Also, some recorders have a special CCTV shooting mode. Suspended from the ceiling and connected to a power outlet, they can act as an alternative to CCTV systems by shooting video with a lower bitrate and frame rate (to reduce the amount of video being shot) ^[6] .

Since 2013, models of DVRs equipped with a Wi-Fi module and capable of transmitting video to smartphones / tablets and to the Internet, to a remote server have appeared on sale. Such devices can be used as IP cameras and also as a security video surveillance system with remote access.

Pedestrian registrars

If you have a battery with a sufficiently large capacity for long-term video recording and fastenings on clothes, DVRs can be used in pedestrian mode - by tourists, travelers, police, etc.

Recorders for bicycles and motorcycles

Special bicycle / motorcycle brackets allow you to fix a portable DVR on the steering wheel of a motorcycle, as well as on any other pipe of a suitable diameter.

Sports Camera

The presence of a battery with a large capacity in the recorder allows you to use it outside the car as an action camera . Some recorders come with special accessories for attaching the recorder to a bicycle helmet or handlebar, to a flat surface, to clothes, to a belt, pressure boxes to protect against moisture and dirt (which can also be immersed in water), etc.

AdvoCam, teXet, Intego brands have models with a waterproof case in the kit. Completely waterproof case at the Highscreen Black Box Outdoor sports recorder.

There are several types of car DVRs, mainly autonomous (portable) recorders and multichannel DVRs (usually in the form of built-in modules). Some time ago, recorders built into the rear view mirror began to be popular.

There are also car navigators with built-in cameras and additional memory card slots on which data is recorded. In Russia, Lexand , teXet , Shturmann and some other brands are engaged in their production.

The widespread use of smartphones based on iOS and Android , as well as the presence of high-quality cameras and a large amount of memory in them, makes it possible to use these devices as car DVRs. There are several dozen applications for both platforms that allow you to "turn your smartphone into a DVR."

Standalone DVRs

In the case of autonomous car DVRs, one or more cameras, a memory card and sensors are simultaneously installed. The advantage of standalone DVRs is the low price, the ability to quickly install / disassemble without the involvement of specialists, the ability to use in a car with a built-in battery. At the time of writing, such registrars are the most popular - according to the Vedomosti newspaper, in 2012, sales of portable DVRs increased by about five times, 1.3-1.5 million car DVRs were sold ^[7] .

Multichannel DVRs

A multi-channel video recorder is a separate unit, which is a recording device to which individual cameras and sensors installed in the car are connected. The number of connected cameras is 2-4. The disadvantage of multichannel registrars is high power consumption, installation complexity, high price (from $ 1000)

Smartphone-based DVRs

Smartphone-based DVRs are programs that allow you to use your smartphone as a DVR. Modern smartphones have high-quality cameras, plenty of memory and processing power, and are also usually equipped with geolocation tools: GPS or Wi-Fi positioning. The advantage of such programs is their price (within hundreds of rubles), as well as the possibility of intellectual integration of the DVR function with other functions of a modern smartphone - navigation, the use of maps with a route, the use of Internet services.

A disadvantage of smartphone-based DVRs is that such devices cannot perform recording functions during calls.

The main parts of a car DVR are a camcorder and a recording device. The camera generates a video signal, which is transmitted to a recording device. The recording device processes the video signal, compresses and records directly. The recorded video signal is stored on a memory card or built-in hard drive.

Recording Permission

Resolution - a value that determines the number of points (raster image elements) per unit area. The resolution determines the clarity of the image on the video, as well as the ability to distinguish between small details when viewing. Among the recorders sold today, the most common are models that shoot in 640 × 480, 1280 × 720 and 1920 × 1080 pixels (Full HD).

In many budget devices, low-resolution video is interpolated to sizes corresponding to HD resolution. However, not all manufacturers indicate this in the characteristics of their device, thus misleading users, since the quality of shooting in natural HD mode and interpolated mode varies significantly. For example, if the real resolution is 640 × 480 pixels, then when stretched using interpolation to a size of 1280 × 960, each pixel is "smeared" into four neighboring ones.

Sweep

Interlaced scanning is a video transmission method in which frames are divided into half frames, in each of which either even or odd lines are transmitted. Progressive scan shows the full frame. You can determine which scan is used by the index indicated in the characteristics: “i” - interlaced scan (for example, 720i - resolution 1280 × 720 pixels), “p” - progressive (720p). Progressive scan gives a better image.

Frame Rate

In modern single-channel recorders with high resolution, the frame rate (FPS, frames per second) usually ranges from 15 to 60 frames per second. For frame-by-frame analysis of a video of an accident, a high frequency is required. Most devices allow you to configure this setting manually. Registrars with CCTV mode shoot at a rate of 6 frames per second specifically so that the saved video has as little as possible.

Bitrate

Bitrate affects the image quality, all other things being equal, the higher the value of this parameter, the sharper the picture looks, but the less time the video material is placed on the memory card. Modern video recorders with a resolution of 1920 by 1080 and a frequency of 30 fps shoot video with a bitrate of 8 ... 20 megabits per second.

Viewing Angle

The viewing angle determines the area of ​​the terrain that falls into the frame. The viewing area depends on the focal length of the lens and the size of the matrix. The horizontal viewing angle of modern registrars varies from 60 to 110 degrees (100-160 degrees diagonally) ^[8] . Too small a viewing angle leads to the fact that only what is directly in front of the car falls into the frame, but not adjacent rows and curbs. At the same time, a too wide angle can cause distortion of the image along the edges - the effect of the fisheye lens . However, given that the purpose of the DVR is not an artistic video, but a video recording of the road situation, this is acceptable (but insufficient visibility can cause important details not to get into the frame). The small size of the matrix and the short focal length make it possible in most cases to use a fixed-focus type lens that does not require focusing.

Compression Format

To store the video signal using the ADC is converted from analog to digital (discrete) form and is compressed. At the time of writing, the following compression formats are used more often than others: MPEG, MPEG4, H.264, M-JPEG. Most commonly used is H.264 (MPEG4 part 10). This compression standard allows you to receive small files with a slight deterioration in quality.

Sensitivity

Sensitivity - the minimum illumination at the subject, at which the image quality can be described as acceptable. Measured in suites. The value of this indicator and image quality has an inverse relationship (0.3 lux gives a picture better than 1 lux). The vast majority of modern car registrars use a CMOS matrix. Such matrices have high resolution, but have low sensitivity.

Image stabilization

While driving on the road, the DVR inevitably shakes and vibrates. In order that this does not affect the quality of the video, digital image stabilization technologies are used.

Auto On / Off

Most modern car DVRs work as follows: when external power is supplied from the on-board network, the recorder automatically turns on and starts recording. When external power is removed, the car DVR stops recording and turns off. There are also devices that are activated when detecting movement or when detecting sound - for this they are equipped with special sensors.

Having your own battery

The presence of a battery with a minimum capacity is necessary to properly turn off the recorder in case of a sudden power outage. Batteries with a large capacity allow the registrar to work autonomously for 2-4 hours. The average capacity of the built-in battery is 800 mAh. Some recorders are positioned as an alternative to a mobile camcorder and are equipped with batteries with a capacity of 1400 mAh (4 hours of autonomous video recording).

Some registrars use a removable BL-5C rechargeable battery, similar batteries are installed in Nokia cell phones. The advantage is the ability to quickly replace the battery without contacting the service.

Loop recording, loss

The possibility of looping video recording allows the DVR to record new data on top of the old. This recording mode eliminates the need for the user to delete the old video on their own in order to avoid overflowing the memory card or hard disk. Car DVRs usually save video in segments of several minutes. Budget devices at the time of creating a new file and saving the previous one cannot take pictures, thus, a 1-3-second interval is lost.

Date and Time Overlay

The vast majority of registrars are linked to video by date and time. Without these marks, presenting evidence as evidence will be problematic.

Integrated Display

Car DVRs can be equipped with LCD displays with a diagonal of 1.5-3.5 inches. Using the display, you can view the footage and make adjustments. Some models are equipped with a rotary display, others - built-in housing.

Video Out

The presence in the car DVR video output (AV or HDMI) allows you to connect a TV, monitor or laptop to it to watch video from a memory card.

Accelerometer

The accelerometer (aka G-sensor) allows the DVR to respond to sudden changes in speed and position of the car (sharp turns, bumps) and activate the so-called. "emergency mode". In this mode, video protected from deletion is recorded.

GPS receiver

In the car DVR, the built-in GPS-receiver has two main purposes - recording the speed of the car and recording the route of movement. As a rule, satellite data is stored as a separate file, which can then be viewed on a computer. Some car DVRs impose speed on a video image (similar to how time and date are superimposed).

In the built-in GPS receivers of the DVRs, the error is from several meters to several tens of meters, and there is no binding to the road; however, with the help of the player program attached to some models on a computer connected to the Internet, the route recorded by the registrar can be traced on the map.

A recorder with a built-in GPS receiver may have additional options; for example, registration of excess of the speed set by the user or synchronization of hours of a registrar on a signal from a satellite .

WDR Function

The WDR function is used to improve image quality of still images and movie recording. It can be used for improved shooting under any adverse lighting conditions. The WDR function in the DVR was named after the abbreviation of the matrix Wide Dynamic Range, which translates from English as “wide dynamic range”. In recent years, even inexpensive DVR models such as Karkam Tiny, Prestige DVR-390 and DVR-478 have been supplied with the “wdr” function. ^[9]

Radar Detector

The built-in radar detector (or radar detector ) responds to police radars (speed meters) and warns the driver about approaching them, usually with an audible signal. Registrars with built-in radar detectors are branded Arena Pro, Highscreen, Rear View. Some models also warn of approaching cameras that record speed violations.

IR LED

IR illumination is used when shooting in “parking mode”, when the recorder left in a parked car automatically takes several photos to detect sound or movement in the field of view.

IR illumination is not used when shooting night video. Firstly, even 8 LEDs are not enough to illuminate the roadway. Secondly, the included IR illumination will even worsen the quality of shooting: when reflected from the glass, the infrared rays will illuminate the sensor.

Wi-Fi Car Recorders

The wireless module in the DVR is used to quickly copy videos from a memory card to another device (smartphone, tablet, laptop). This allows you to quickly make a copy of the video from the accident, which you witnessed.

To connect the device, you need to activate the access point on the DVR and run the corresponding application on the smartphone. On some cameras, streaming playback of previously recorded videos on the smartphone’s screen via Wi-Fi is available. In addition to watching and copying videos, such a connection to the recorder via Wi-Fi allows you to change settings, delete videos, and even watch a picture from a camera online via the Internet ^[10] .

Car recorders come with accessories. The recorder kit includes:

• Glass mount.
• Cigarette lighter charger.
• USB cable for connecting to a PC.

Optionally available:

• Memory card.
• Additional charger (from the outlet).
• Additional fastening in the car interior.
• Mounts on the steering wheel of a motorcycle or bicycle.
• Mounts on flat surfaces (based on 3M tape).
• Remote control.
• Attachment to clothes.
• Germoboks for protection against moisture.
• Carrying Case.
• AV cable.
• HDMI cable

• Police of the Arkhangelsk region use car DVRs on foot patrol ^[11]
• Most of the videos were captured by the video recorders, which recorded a flash from a meteorite explosion over the Urals on February 15, 2013 . Most videos were shot in Chelyabinsk and its environs.

• Action camera
• Webcam

• "Valuable shots: choosing a car DVR", the site of the magazine "Behind the Wheel"
• "Car cam. Legal advice »Courier. UA All-Ukrainian Internet newspaper
• “Lawyers cameras: how to choose a high-quality video recorder?”, The website of the newspaper “Komsomolskaya Pravda”
• “To whom - what? DVRs for individual requests ”, the website of the newspaper“ Komsomolskaya Pravda ” .