API : An acronym for Application Program Interface. This is used by programmers and refers to the interface providing the calling conventions for an application program to access the operation system.
A & E : This is an acronym for Architect and Engineer. It refers to a person or a firm. In reference to CCTV, an “A&E” can range from a single individual consultant that provides customers with valuable product and industry information, to a large firm that manages entire construction projects and all the associated systems that are installed in the building. CCTV/security is only a small part of the overall project.
A&E Specifications: “A & E specs” in CCTV are written technical specifications for individual products. Theoretically the A&E (or the customer) writes the specifications to be put out for bid to selected sales organizations. Manufactures typically “help the process” by providing A&E specifications for their products and the A&E can cut and paste the appropriate parts into the official spec. There is no real standard for the format of these documents in the CCTV/security industry so they can vary widely in format from one manufacturer to another. Some manufacturers are writing their specs to adhere to the CSI (Construction Standards Institute) format.
Active X Commands: This is a Microsoft program interface to share information between programs. Browser based programs use Active X components for viewing video from DVRs.
Activity Log: This log is a gathering of information about system operation. In a DVR it would list occurrences like log on/log off, menu access and changes, remote connections, and any other operation information that is relevant.
AGC: Automatic Gain Control automatically increases the video signal in low light conditions. AGC is available in many cameras and some other CCTV devices.
Alarm Activated VCR : After pressing `record', a normal VCR takes about 20 seconds before it starts recording usable pictures. With an alarm activated recorder it can be set so that the tape is ready to start recording in about one second. The signal to begin recording can be from an alarm or any other input.
Alarm Inputs : Any activity that provides a trigger for an alarm action. This can be a physical wired device, a recognized video motion change, or any recognized changes in data that are selected to provide an output alarm.
Alarm List : This is a list of alarms that have occurred in the unit. The list typically indicates the time/date, the type of alarm and any other information that is deemed relevant by the design.
Algorithm : A consistent method of steps used to accomplish a task. In CCTV it often refers to video compression algorithms.
Alpha Test : This refers to the first outside the development group testing on a newly developed product. The product is still in the development stage and bugs are to be found and corrected before initial shipments.
Analog : In reference to CCTV, this refers to systems and components that use the standard NTSC/PAL composite video formats. Digital refers to devices that use pixel formats. The definitions become blurred when you consider that DVRs convert the analog signal into digital form to process the images internally, they convert back to analog to output to other devices. Details aside, many people refer to analog as old technology and digital as the new technology.
Aperture : The light gathering area of a lens, controlled by the iris.
Application : How a product or system is used to solve the customer’s problem. Application is how the operator uses the system to accomplish his job. See Vertical Market for a marketing definition of applications.
Applications Support : This refers to the organization and individuals that provide pre-sale support to clarify issues, select products and design custom systems.
ASCII : An acronym for American Standard Code for Information Interchange. This is a standard format for sending data.
Aspect ratio : The ratio of the vertical to the horizontal image size. This is usually 4:3 for analog video. A wide screen monitor typically has a 16:9 video format option.
ATM : An acronym for Automated Teller Machine. It also is an acronym for Asynchronous Transfer Mode (a data communication method).
Attenuation : This refers to signal loss in a transmission system over distance.
Auto Tracking : This refers to the ability of a PTZ camera to sense movement in the image and follow the movement wherever it goes. The actual intelligence for the function can be in the dome or in the DVR. The advantage is that you can follow the movement of an individual anywhere within the range of the camera. This comes under the heading of video analytics.
AVI : An acronym for Audio Video Interleaved. This is a typical video format used in the PC world that can be read by a variety of standard programs. Some DVR manufacturers can export video to AVI files for easy review in a standard PC.