Analogue Camera

Analogue CCTV cameras generate images that are usually of lower quality of digital (IP) cameras. The signal that these cameras generate is subject to noise and is transmitted over coaxial cable. The highest resolution that can be displayed is less than .5 megapixels.

CCTV Client

A CCTV client is a computer located on the same network as a network video recorder or digital video recorders that is used to access and display live or stored video, and to control the functions and operation of the system.

Codec

A codec is  a device that connects to an analogue camera and converts the signal into a digital stream so that the camera can be accessed over a network or connected to a DVR.  This device is very useful for converting existing analogue CCTV cameras for use with solutions such as Exacqvision.  CODEC  is an amalgamation of the words CODer and DECoder.

Digital Video Recorder (DVR)

Digital Video Recorders take analogue camera signals as inputs and then convert the information so that it can be stored on hard disk.  This has the limitation on image quality imposed by analogue cameras, but offers the benefits of a digital system. The benefits include Remote access/playback, image manipulation, and transmission of the video over computer networks.  DVR’s also provide motion detection settings and PTZ camera controls.

IP Camera

IP cameras generate an image that is output in digital format via an Ethernet port.  Many of these cameras can also be powered using Power Over Ethernet (POE) meaning that power and data can be sent over a single cable.    These cameras are available in a variety of resolutions from a level comparable to analogue cameras up to a level that exceeds them by 50 times.  The IP part of the name is derived from Internet Protocol which is the network protocol used for communications.

Megapixel Camera

Digital camera image quality is defined by the resolution or number of pixels that make up each video image.  Megapixel cameras produce a video image where the total number of pixels is greater than 1 million.   Currently 1, 2, and 3 megapixel cameras are most widely used, however other resolutions are available including specialised cameras  with a resolution of over 20 megapixels.

Network Video Recorder(NVR)

A Network Video Recorder is a digital device which is installed on an IP network to receive live digital image/video streams and record them to a hard disk.  The NVR can be a dedicated hardware appliance, or a computer server with the appropriate software installed.    This device differs from the DVR in that the data it records is already in digital format when it is received.

Pan Tilt Zoom (PTZ) Camera

A PTZ camera is one where the lens can be panned from left to right (or vice versa), tilted up or down, or zoomed in to provide greater detail.   The camera functions are controlled remotely by an operator or can be programmed to follow a sequence of actions.   PTZ cameras are available as Analogue or IP connected.