When talking in security and surveillance camera system circles, you may have heard “DVR for IP Camera” mentioned. That’s understandable because these systems are becoming very popular these days very fast. In the following article will explain what all the abbreviations mean, how a typical system works verses a DVR for IP camera, and what an NVR is.
First, let’s talk about a non-IP or non Internet Protocol security camera system. This system typically consists of digital video cameras (non-IP), a Digital Video Recorder or DVR, and one or more monitors. In simple terms, the cameras are needed to capture the video image, the DVR records the images, and the monitor displays them.
A more “in-depth” view includes the following. The camera lens gathers the light reflected off objects in its field of view and focuses that field of view on to a very small sensor chip (often 1/4 or 1/3 inch square). There are actually two different types of sensor chips but only one is needed to do the job. One type is called a Charged Coupled Device or CCD and the other is a Complementary Metal Oxide Semiconductor or CMOS. Although they go about it somewhat differently, both chips yield the same end product: They change the light energy from the lens into electronic impulses that can be used to create video images.
The camera translates the impulses into an electronic image and then digitizes it. Ironically enough, a digital camera actually creates an analog image that must be converted to binary (digital) code before it leaves the camera. It may also contain other specialized Integrated circuit chips that enhance the image and correct any flaws. These special chips are called Digital Signal Processors or DSPs.
Once the signal is prepared to leave the camera it is sent along a co-axial video transmission cable such as RG-59 to the DVR. Some systems are “wireless.” Wireless systems include a camera with a built in transmitter and antenna. Instead of sending the signal along a cable, the camera changes it into a radio signal that is sent to a corresponding receiver that is connected to the DVR.
Once the signal reaches the DVR, it is processed further. A COmpression/DECompression or CODEC is employed to reduce the incredibly large size of the file without sacrificing a large amount of quality. The DVR then stores the file on its Hard Disk Drive for later viewing or archiving purposes. If a monitor is used, it also provides it with the finished signal.
In contrast, a DVR for IP camera system basically uses the Internet as the vehicle of transmission for the video image. It may also send the image over cable directly to the DVR simultaneously. The camera also has a built in web server and prepares the signal for both the Internet and the direct link to the DVR using one or more CODECs. A popular method is to use the latest CODEC for streaming directly over the Internet, H.264, and for saving to the recorder MJPEG.
DVR for IP camera systems do not necessarily require a DVR to work. The camera sends the signal over the Internet and the user/receiver uses a standard Internet browser to display the image. If a recorded image is needed, the browser can save it to the personal computer on which the video image is being viewed.
The key advantage to using an IP camera over a non-IP camera is that cameras can be located thousands of miles apart and still be on a networked system. As long as there is access to broadband Internet the IP camera can use the Internet as it would a transmission cable and pipe its data to just about anywhere.
Although the IP camera may be able to work alone, most systems will be of the DVR for IP camera type. Before we end this article we should make it clear that when dealing with IP networking systems, the DVR is usually called a Network Video Recorder or NVR and it does operate a little differently than a DVR.
However, just the same, the NVR on a DVR for IP camera system is for storage of all the cameras’ video images and for central control of the system.
If you would like more information on a DVR for IP camera system, please contact one of our security experts as they will be glad to help.