Digital Video Recorder

Digital video recorder is a device for recording, storage and playback of video information received from surveillance systems.

Depending on the objectives DVR can be used for various tasks, including:

• Video surveillance over visitors in private houses, offices, shops;
• Cash transactions video control;
• Monitoring systems creation in parking lots;

Digital Video Recorder is similar in structure to a computer or video server and contains in its composition analog-to-digital encoder, processor, hard drive and other components. Dedicated operating system can be installed to control DVR. Before recording digitized video images are subject to compression so that they would take up minimum space. Almost all DVRs can process both monochrome and color videos. DVRs have the ability to connect to the network for video images transmission onto remote computers. A major competitor of DVR surveillance systems are now computer-based video servers. 

DVR Modifications

DVRs are characterized by the following parameters:

• Functionality (simplex, triplex, pentaplex);
• The number of input video channels;
• Recording frame rate;
• Resolution;
• Type of compression;
• The volume of the recorded information before rerecording;
• The possibility to connect external storage devices;
• The possibility to connect audio channels;
• The possibility to connect IP cameras;
• The possibility to connect external devices (via relay inputs / outputs);
• Networking capability.

At present, some varieties of DVRs were allocated in subgroups that have their own names:

• NVR. Operates with IP cameras only;
• PC-based DVR;
• HDVR. Operates with analog and IP cameras;
• Stand alone DVR. Operates with analog cameras only.