The security camera computer of a digital video security and surveillance system is basically the “brain” of the system. This is where the COmpression/DECompression or CODEC utility is normally used to shrink the size of the incredibly large digital video files made by the security camera. The security camera computer is also the central controller for the entire digital video system, coordinating all the actions of the components in the system.
Another name that is more commonly used instead of security camera computer is Digital Video Recorder or DVR. Although admittedly, there are some systems where the DVR is only a storage device and does not control the entire system. Let’s start from the beginning to see just exactly what a security camera computer does.
An average digital video security surveillance system is a component system that consists of three major components (it may have more or less depending on the system). The components are the digital video cameras, the DVR, and the monitor. Note that the phrase “security camera computer” did not appear anywhere in the previous sentence, although the functions of a security camera computer are normally considered the tasks of the DVR.
The digital video security camera creates an electronic based video by converting the light images gathered by the lens and focused on a special sensor chip. The sensor chip contains pixels that when struck by light emit an electronic pulse that can be measured, interpreted and used to create and electronic recreation of the field of view of the camera.
Interestingly, up to this point, everything has been in analog format. The camera has a special processor called an analog-to-digital processor that converts the analog information into digital data. Cameras normally contain another processor that helps to stabilize and improve the display of the digital video. This processor is called a Digital Signal Processor or DSP. Once the data has been processed by the camera it is sent to the security camera computer (or DVR).
There are basically three types of security camera computer. The first we’ve already mentioned; it is the most popular type of security camera computer in use today and is called the DVR unit. While it’s true the major function of the DVR is to process and store digital video files, it generally coordinates the activities of all the other components within the system.
For example, the DVR (or security camera computer) is either responsible for or performs the following actions for the digital video security system:
- CODEC application – the security camera computer uses a CODEC utility to shrink the size of the digital video file while maintaining as much original detail and quality as possible.
- Operation of special uses cameras – The Security camera computer may also be equipped to control special use cameras such as a Pan-Tilt-Zoom or PTZ camera. It may include programming the automatically initiates the PTZ camera to “lock on” on track or follow a specific object (such as a car in a parking lot).
- The security camera computer also coordinates activities within the DVR itself. For example, many DVRs are capable of recording several cameras at once while simultaneously playing back previously recorded video.
- The DVR may also contain the components required to access the Internet and make controlling the system form anywhere in the world that 3G or 4G smartphones can operate.
The second type of security camera computer is the Network Video Recorder or NVR. The NVR typically doesn’t control as many accessory type functions as a DVR. The NVRs role is to coordinate the use of single or multiple Internet Protocol (IP) ready cameras. This could mean that a camera could be placed at one address and another in a totally different location (such as a different city) and by using the Internet is able to “network” these cameras as is they were one local system.
Finally, the third type of security camera computer is, of all things, a computer! These systems usually have plug and play PCI cards that are installed on the computer. The PCI card may perform a great many of the functions that are needed using the computer only for storage purposes on its own hard drive. Nonetheless, this is a type of security camera computer.