Digital Video Recorder or DVR is the most important part of your surveillance system. It is responsible for management and recording of camera feeds. DVR isn’t just responsible for recording the camera feeds but displaying live camera feeds as well. The storing in the DVR is done using an internal hard drive or an external storage unit depending upon the requirement of the user. You don’t need any DVD or VHS tape unless you deliberately want to record on them.
How Does It Work?
A DVR hooks itself up with your entire camera system and a television. The connection is exactly like that of a DVD player or a gaming console. You connect the appliances to the DVR using BNC connector if the cameras provide analog signals.
Recent cameras are coming in digital format, which is transmitted via a network connection. This eliminates Hikvision DVR back door threats as no one can actually access the DVR manually. This type of recorders is known as NVRs or Network Video Recorders.
For DVRs, the analog signals from the cameras are first converted to a digitized version. This is done using compression. This compression is mainlybased on image compression methods like WAVELET or JPEG. JPEG is the most common form of compression. Each video picture is then stored as a separate entity. While you view these recorded images, they use motion predictive methods like MPEG2, H.264 and MPEG4 and they are finally converted to a proper motion video.
Depending upon the compression method, the quality of the video is determined. If the compression is high, the video quality is low and if the compression is low, the video quality is high. The capacity is also directly proportional to video quality. Therefore, the higher the video quality, the higher the storage capacity is required.
The storage units of DVR recorder have long lasting hard disk drives that are supposed to be stored in a safe working temperature and away from shocks or vibrations so that they stay long lasting.
DVRs come as 4 channel, 6 channel, and 8 channel and so on. The number of channels relatedirectly to the number of cameras that can be connected to the DVR. The higher the number of channels, the more power the DVR consumes. More power means more heat, therefore, it is important to keep the DVR in a cool place or else it might malfunction.
Now that you understand what DVR is and the working of it, go ahead and purchase a DVR surveillance system.