Surely everyone in life there were times when there are no witnesses of an accident, he could not prove his innocence or innocence in the incident.In such cases, help can only video recorder - a device for recording and processing of digital video with the ability to replay it.These technical devices have long ceased to be a rarity in the electronics market, but many still do not know what a DVR, and what it's for.
Although recognized classification DVR on any specific criterion does not exist, some devices still took shape in separate groups:
- NVRs (Network Video Recorders) - this device for recording, storing and playing back videosreceive a signal directly from IP-cameras and archives the data for storage.
- Hybrid Video Recorders (Hybrid Digital Video Recorders) - a device for recording, storing and playing back videos with both analog and IP-based cameras with.
- DVR PC-based (PC-based Digital Video Recorders) can multitask by using the computer's capacity.
- Car DVRs (Car DigitalVideo Recorders) are used to record traffic from inside the car, truck, boat and other vehicles.They are also sometimes referred to as mobile, in contrast to the other, stationary, registrars.
However, there are other classifications.For example, the number of channels to record video recorders signal can be single-channel, dual-channel, four-channel, six-channel and eight-channel.
DVR functions and area of use
Complete DVR has the following features:
- FullHD record - the highest quality recording format to date (1920x1080 pixels).
- GPS-receiver - irreplaceable thing in emergency situations.Shows recorded on the coordinates and speed.
- G-sensor - the sensor, which is able to accurately determine which side was perfect kick.The sensor data can be used in court as evidence.
- IR illumination - ensures a full record, even in the dark.
- Zoom - to increase the possibility of a video recorder or a fragment of the image.
Depending on the purposes for which designed DVR, some devices may not function or be realized as a smaller (for example, a recording format may be VGA, and Zoom - only twice or missing at all).
So, DVR can be used not only in cars, but also:
- in video surveillance systems of private houses, office buildings and various public buildings in conservation purposes;
- cafes, snack bars, restaurants and shops to monitor the activity of the personnel.Video surveillance allows, for example, to identify the cause of the discrepancy amounts of money at the box office and data with POS;
- at various checkpoints and organizations equipped with point guard, for the account of visitors and vehicles, residing in the territory of accountable;
- in large enterprises and in the various centers where the necessary control of all processes taking place simultaneously in such a large area, etc.
principle of operation of the DVR
most general operation of the DVR can be summarized as follows:
- camera is designed to perform a specific task, removes what is happening with a certain time interval, specify settings, and transmits the video signal cable to the DVR.
- device processes the received signal based on the date, time and duration of the video.
- archives or special codec compresses the data and saves them to the internal memory or memory card.
Depending on the model of DVR can be connected to it at the same time up to 8 analog or ip-cameras.Additionally, you can connect a microphone, and the video will also be superimposed audio.Shelf life video on the DVR depends mainly on the amount of hard disk memory to which it is connected.
Read this technical device, see also article:
- How to use DVR
- How to connect the DVR
- How to install DVR
- What should I look for when choosing DVR