Arc—In fiber optics, the discharge that may occur between the two electrodes of a fusion splicer.
AACS-Advanced Access Content System—A digital rights management standard utilized with Blu-ray Disc and other optical formats. AACS incorporates two parts: a set of embedded decryption keys within the source device, and a set of keys encoded in the content that describes each of the playback devices licensed to utilize the content. This approach allows copyright holders to revoke the keys of a particular source device, thus preventing it from playing back future content. AACS also provides for a managed copy system, that is, a mechanism by which one or several, but not an unlimited number of copies can be legally made as backups, for storage on a media server, or for use on a portable device. The ICT – Image Constraint Token is a provision within AACS that allows the content provider to limit analog output resolutions.
AAP-Architectural Adapter Plate—Mountable metal plates available in hundreds of models offering popular pass-through audio, video, phone, data, power, and control connectors. Active AAPs are also available for power, control, and long distance signal transmission. Along with mounting options for maximum flexibility in placing connectors and controls within reach, these interchangeable components fit together to create an attractive and completely customizable A/V connectivity solution.
A/B comparison—A back-and forth listening comparison between two audio or video presentations, A and B.
Absorption—The attenuation of light as it passes through fiber, similar to the resistive loss of an electrical signal as it passes through cable. Absorption is caused by impurities and defects in the fiber.
AC-3—The encoding format used to create Dolby Digital, the 5.1-channel discrete digital surround-sound format. A digital surround-sound system introduced by Dolby™ laboratories. The system is usually comprised of 5.1 channels (6.1 nowadays and counting)- five/six discrete channels - left, right, center/s, back left and back right. In addition one Subwoofer covers the bass (low frequency signals, representing a limited spectrum of audio, hence the .1 designation) that belongs to all channels. As the ear is not sensitive to the direction of the very low frequencies, the "low-bass" area, one Subwoofer is sufficient. In order to retrieve and decode AC-3 sound channels, a special amplifier/receiver is needed. The AC-3 system is also available on some digital video equipment for recording and playback, such as a DVD*. Similar digital 3D sound schemes are also available such as THX®, DTS® and others, as well as Dolby surround*, which is an analog scheme.
AC-Alternating Current—Electron flow that changes direction alternately.
ACC-Automatic Chroma Correction—A system built into some VCRs and TV sets for automatic adjustment of color saturation levels. Most ACC systems measure the Color Burst* amplitude and use it as reference. As the system is automatic, erroneous color levels can appear in the video scene - an original grayish scene can become over colored, or a rich, saturated-color scene can become dull.
AC coupled—A circuit design that does not pass the DC component of a signal, therefore it ignores DC offsets.
AC Line-Conditioner/Protector—A device that filters noise from the AC powerline and isolates equipment from voltage spikes and surges. Some AC line-conditioners/protectors also protect equipment from lightning strikes. Home-theater equipment is plugged into the AC line conditioner/protector, and the conditioner is plugged into the wall.
Acceptance Angle—In fiber optics, this is the critical angle, measured from the center axis of the fiber. Incoming light must be directed below this angle in order to enter the core of the fiber and propagate along its length through total internal reflection.
Acceptable Viewing Area—A viewing range for a screen suggested as a 45-degree line extending hutward from the left edge and right edge of a displayed image.
Acoustics—The science of sound wave behavior in air.
Acoustic Absorber—Any material that absorbs sound, such as carpet, drapes, and thickly upholstered furniture.
Acoustic Diffuser—Any material that scatters sound.
Active Subwoofer—A speaker designed to reproduce only low frequencies and that includes an integral power amplifier to drive the speaker.
Active Video—The part of a video signal visible on the screen.
A/D-Analog to Digital (converter)—A device that converts an analog signal to a digital value.
ADC-Analog to Digital Converter—A device that converts analog signals to digital signals. The process may be done with different levels of accuracy. The conversion fidelity is dependent on two factors - sampling rate and number of bits. The higher the rate and/or bits used during conversion, the more accurately the analog signal is reproduced. Until recently, the most common video sampling speed was four times the color subcarrier frequency (4xFsc - 17.7 Msamples/sec for PAL 14.3 Msamples/sec for NTSC) Today, the standard (industrial and broadcast) tends to be 13.5 Msamples/sec for luminance signals. For color difference signals it is usually half for both PAL and NTSC. Industrial video signals are digitized at 8-bit accuracy (256 levels) while broadcast signals are digitized at 10-bit accuracy (1024 levels) or even at 12 bit. Hi-Fi audio signals are usually sampled at double the highest frequency audible to the human ear, i.e., 20 kHz (or more - sampling at 44 kHz or even higher frequencies) with an accuracy of 16 bits or more.
Adapters—Adapters are used as interfaces in audiovisual technology to change from type of connector, signal format or power source to another.
Adaptive Comb Filter—A Comb Filter* that uses adaptation technology - changing its operation parameters by dynamically following changes in the picture.
Additive Color Process—Also called “RGB.” A color generation process used in video that combines red, green, and blue to make all colors. All three colors (red, green, and blue) at 100% combine to make white on a video screen; the absence of all three colors (0%) makes black. Also see "Subtractive color process."
Adjacent-Channel Selectivity—Tuner specification that describes a tuner’s ability to reject radio stations adjacent to the desired station.
Adobe RGB—A color space specification developed by Adobe® Systems, Inc., offering a wider color gamut than sRGB. Adobe RGB is supported in Photoshop® and other Adobe software, as well as some digital cameras, printers, scanners, and displays.
ADSL-Asymmetrical Digital Subscriber Line—One of a number of DSL technologies, and the most common one. ADSL is designed to deliver more bandwidth downstream (from the central office to the customer site) than upstream.
ADSP™-Advanced Digital Sync Processing™—Using sync processing to allow centering control (H-shift or V-shift) can create problems with some display devices because of the sync delay. This means the digital projector user may have to choose between a stable sync and centering control. Extron's ADSP restores the original sync timing relationship for a stable sync signal while allowing centering control.
ADTV-Advanced Definition Television—An early HDTV system proposed by the Advanced Television Research Consortium in 1992. Now superseded by US HDTV standards.
Aerial Cables—Optical fiber cables designed for outdoor installations on aerial supporting structures such as poles. They are specifically designed to withstand adverse conditions such as wind and ice loading, pollution, UV radiation, thermal cycling, stress, and aging.
AES-Advanced Encryption Standard—A data encryption standard adopted by the US Government and approved by the National Security Agency for top secret information. DCP, LLP, the licensing agency for HDCP, has adopted AES 128 encryption for the new HDCP 2.0 standard.
AES/EBU-Audio Engineering Society/European Broadcasting Union—A digital audio transfer standard. The AES and EBU developed the specifications for the standard. The AES/EBU digital interface is usually implemented using 3-pin XLR connectors, the same type of connector used in a professional microphone. One cable carries both left- and right-channel audio data to the receiving device. Also see "AES3."
AES3—A digital audio standard defined by the Audio Engineering Society. The standard specifies several basic physical interconnections between devices.
AFL™-Accu-RATE Frame Lock™—Extron's patented method of eliminating image tearing which is associated with scaling, especially when motion video is involved, and occurs when the input frame rate is slower or faster than the output frame rate and part of the old frame and part of the new frame are displayed at the same time during a refresh cycle. Extron Accu-RATE Frame Lock sets and locks the output frame rate to the input frame rate of a designated input and produces a tear-free output in a seamless switching system.
AGC-Automatic Gain Control—A circuit used to automatically control the level of the recorded or transmitted signal. It is sometimes called Automatic Level Control (ALC), or Automatic Volume Control (AVC).
Air Blown Fiber-ABF—Optical fiber installed through special tube cables by means of using pressurized air or nitrogen to "blow" bundles of fibers through individual tubes within the cable. Tube cables are usually preinstalled at the premises before installation of air blown fiber.
Air Polish—In fiber optics, this is the first step in polishing the connector using special fine grit film, after the fiber has been cleaved.
Alarm Camera Scanner—An electronic device, mainly used in security installations, where several video cameras positioned in different locations on the premises, scan automatically, and are viewed one after the other on one monitor. When an intrusion occurs in the field-of-view of one of the cameras, a special alarm signal is sent to the scanner instantly activating the particular camera in question. It usually triggers an additional alarm device drawing attention to the event. Sophisticated scanners have internal microprocessor control, allowing them to skip or analyze every scanned source, as well as activating, when necessary, a special device, which relays a suspicious camera image to a remote location for monitoring via a telephone line.
ALC-Automatic Level Control—In audio recording, a circuit used to control the volume or level of the recorded signal automatically without distortion due to overload. Sometimes called Automatic Gain Control (AGC), or Automatic Volume Control (AVC).
Aliasing—(1) Aliasing occurs when smooth curves and lines become rough or jagged because of a lower resolution device, or by an event. (2) In analog video, aliasing is typically caused by interference between the luma and chroma frequencies or between the chroma and field scanning frequencies. It appears as a moiré or herringbone pattern, straight lines that become wavy, or rainbow colors. Also see “Cross color.” (3) In digital video, insufficient sampling or poor filtering of the signal causes aliasing. Defects typically appear as jagged edges on diagonal lines and twinkling or brightening in picture detail.
All Dielectric—In fiber optics, this denotes the presence of only dielectric, or non-metal elements.
Alpha Channel—The Alpha channel is a separate channel of data, transmitted alongside the original color or video information - whether it is video or computer based. It is used to specify an Alpha value for each color pixel in order to control pixel based image blending and mixing. Values of the Alpha channel range between 0 and 1. (In SDI applications the Alpha channel uses 256 different levels from 0 to 1)
Alpha Mix—Image blending and mixing based and controlled by the Alpha Channel data stream.
Alternate-Channel Selectivity—Tuner specification describing a tuner’s ability to reject stations two channels away from the desired station.
AM-Amplitude Modulation—A method of radio transmission, by which the information part of the signal causes the amplitude of a carrier frequency to vary without affecting the frequency.
Ambience—Spatial aspects of a film soundtrack that create a sense of size and atmosphere, usually reproduced by the surround speakers.
Ambient Light—All light in a viewing room produced by sources other than the display.
Ambient Noise—Sound that is extraneous to the intended , desired, intentional, audio; background noise.
Ambient Sound Level—Any environmental or background sound that exists before a new sound source is added. For example, in a school classroom, ambient sound may come from an adjacent hallway or playground, HVAC system, room lights, or another classroom. Ambient sound must be taken into consideration when designing a sound support system.
Ambient Sound List—Any environmental or background sound that exists before a new sound source is added. For example, in a school classroom, ambient sound may come from an adjacent hallway or playground, HVAC system, room lights, or another classroom. Ambient sound must be taken into consideration when designing a sound support system.
American National Standards Institute (ANSI)—ANSI is a private, non-profit organization that administers and coordinates the voluntary standardization and conformity assessment system in the US.
AMORPHEOUSLCD—An obsolete LCD display system, suffering from many technical flaws, replaced by polysilicone-type and other active displays.
Amp-Ampere—The international base unit of electrical current that represents the rate flow of electric charges through a conductor. Symbolized by “A.” 1 amp is equal to the steady current produced by 1 volt applied across a resistance of 1 ohm.
Amplifier—An electronic device used to increase the voltage amplitude of a signal.
Amplifier Classifications—Audio amplifiers are typically described by “class”. There are four primary classes used in A/V system designs: A, B, A/B, and D.
Amplitude—The level or strength of a signal as measured by the height of its waveform. Electronic waveforms can be displayed and measured on an oscilloscope.
Amplitude Modulation-AM—Amplitude modulation is also employed in fiber optics applications, in which light acts as a carrier signal with its amplitude varying in accordance to the signal being conveyed.
Anaerobic—For fiber optics, this describes a method of bonding between optical fibers via a non-heat, intrinsic chemical reaction within the adhesive material. By definition, an anaerobic adhesive does not require air to cure.
Analog—A continuously varying action or movement that takes time to change from one position to another. Standard audio and video signals are analog. An analog signal has an infinite number of levels between its highest and lowest value (unlike digital, in which changes are in discrete steps).
Analog Control—A method using continuously varying voltage levels to provide control of equipment.
Analog Monitor—A video monitor which accepts analog level signals. Several types of inputs are accepted by analog monitors making them very flexible: composite* video, RGBS*, YC*, YUV* and any combination of these standards. The signals transmitted to an analog monitor are usually between 0 and 1 Volt and use 75-ohm coaxial cables.
Analog Sunset—When used colloquially, may refer to the general trend of digital video technologies displacing analog, such as when US broadcast television switched to digital transmission, or the increasing use of DVI, HDMI, and DisplayPort video on PCs instead of RGB, etc. In a narrowly defined legal sense, the analog sunset refers to AACS licensing restrictions placed on Blu-ray Disc players where licensed players produced after 2010 must limit analog video output to standard definition, and licensed players produced after 2013 must not output any analog video, when playing protected content.
Analog Video Signal—Signal in which the output varies as a continuous function of the input, while the values of the transmitted information are within defined limits. Any variation in an analog video signal may represent a specific video parameter, e.g., when the luminance* signal is high (0.7 V above black level) the picture is very bright. When the signal is low (0.1 V), the picture is very dark; at 0 V the picture is totally black. TTL* digital signals, in contrast, are predefined as only 0 or 5 V or other fixed logic levels, and do not vary.
Analytics—Google Analytics is a freemium web analytics service offered by Google that tracks and reports website traffic. Google launched the service in November 2005 after acquiring Urchin. Google Analytics is now the most widely used web analytics service on the Internet.
Anamorphic—A type of lens or adapter designed to produce a widescreen image from a condensed image on the film. Trademarked anamorphic systems include CinemaScope, VistaVision, and Panavision.
Anamorphic DVD—A DVD with a widescreen video image that has been horizontally squeezed to fit into a standard video frame, resulting in an image with higher resolution than letter boxing can produce. Anamorphic DVDs are designed for optimal display on 16:9 widescreen displays or video scalers with an anamorphic squeeze mode.
Ancillary Data—Data added to a digital video data stream including information such as embedded digital audio, control signals, etc.
Android (operating system)—Android is a mobile operating system (OS) currently developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets.
Anechoic Chamber—An acoustic space without echo or reverberation. Often used for the acoustic testing of microphones and loudspeakers.
Angle of Incidence—The angle between a ray incident on a surface and the line perpendicular to the surface at the point of incidence, called the normal
Angled Physical Contact-APC—A specific technique for singlemode fiber applications where the endface of the fiber or ferrule is cut and polished at an 8 degree angle in order to increase contact surface area and help minimize return loss. APC connectors are typically green in color and are not used in multimode applications. They are also rarely used in digital applications. APC polished connectors are not compatible with UPC, SPC, or PC polished connectors. Intermixing APC polished connectors with UPC/SPC/PC polished connectors can damage the fiber optic cable or equipment.
Angularly Reflective Screen—A screen that reflects light back to the viewer at a complementary angle.
Animations—Animations consist of motion image sequences produced synthetically on video processing or computing systems.
Annotation—Annotation allows a presenter to mark up a displayed image as a means of highlighting specific information. Annotation technologies include interactive pens & displays, whiteboards, handheld tablet devices, touch-sensitive screens and more.
ANSI Lumen—The common unit of measurement for the light output of a projector, as measured by ANSI, the American National Standards Institute. The higher the ANSI lumen rating, the brighter the projector. In general, there needs to be about a 30% differential in the ANSI lumen rating before the human eye can really notice an appreciable difference in brightness when two projectors are shown side by side. Determining the lumen output for a given application depends on five factors, (1) the level of ambient room light (2) the size of the audience, (3) the size of the projected image, (4) the quality of the projection screen, and (5) the amount of detail in the presentation material. Also see "Lumen."
Antialiasing—A technique in computer graphics for smoothing jagged edges by blending shades of color or gray along the edges. Some video devices, such as character generators, have an antialiasing feature to minimize aliasing through filtering and other techniques. Also see "Aliasing."
Aperture—The opening, usually an adjustable iris, that controls the amount of light passing through a lens. In motion picture cameras, the mask opening that defines the area of each frame exposed. In motion picture projectors, the mask opening that defines the area of each frame projected.
Aperture Grill—A grill-like feature of Sony Trinitron CRT monitors and others licensed by Sony that controls the number of electrons hitting the phosphor coating on the screen.
API (Application Program Interface)—A set of routines, protocols, and tools for building software applications. The API specifies how software components should interact and APIs are used when programming graphical user interface (GUI) components.
APL-Average Picture Level—A measure of average video luminance level expressed as percent of maximal white level. When the APL is low, the picture is dark, when the APL is high the picture is bright.
Apple Cinema Display—One of the first very high resolution monitors on the market and one of the first to utilize a dual-link DVI connection. The 30" version provides a native resolution of 2560x1600 pixels.
Appliances—Digital signage appliances are processing devices that support networks or help manage distribution or playback of digital signage across multiple screens or devices.
Aramid Yarn—A woven strength member, with Kevlar® as a common brand, incorporated into fiber optic cable that provides tensile strength and protection.
Arc—In fiber optics, the discharge that may occur between the two electrodes of a fusion splicer.
Archival Systems—Archival systems are equipment-based systems designed to ingest, organize & access multi-format rich-media content.
Armored Cable—Cable that is protected with metal sheathing or rods below or between the cable jacketing to protect from damage due to adverse outdoor factors such as rodent attack.
ARP-Address Resolution Protocol—A protocol for assigning an IP address to a device based on the device’s MAC (Media Access Control), or physical machine address, that maintains a table showing the correlation between the two.
Artifacts—Any error in the perception or representation of any visual or aural information introduced by the involved equipment. Image artifacts appear as deviations from the original in the delivered image in video streaming systems.
ASCII-American Standard Code for Information Interchange—The standard code consisting of 7-bit coded characters (8 bits including parity check) used to exchange information between data processing systems, data communication systems, and associated equipment. The ASCII set contains control characters and graphic characters.
Aspect Ratio—The relationship of the horizontal dimension to the vertical dimension of an image. In viewing screens, standard TV is 4:3, or 1.33:1; HDTV is 16:9, or 1.78:1. Sometimes the “:1” is implicit, making TV = 1.33 and HDTV = 1.78.
Assistive Listening Devices—Assistive listening devices provide enhancement of sound for people who are hard of hearing. The Americans with Disabilities Act mandates the use of assistive listening devices in certain environments.
ASTA-Active Sync Termination Adapter—A VGA-style (15-pin HD connector) adapter that provides active circuits that shape up the horizontal and vertical sync signals. This adapter may be used to eliminate jitter and/or intermittent tearing in the displayed image. Most small digital projectors are designed to be near the video source and may not provide impedance matching.
Asynchronous—Intermittent, not synchronized or continuous. A conversational type of communication that allows the parties at each end to talk when they like instead of at a prescribed time. Used in videoconferencing.
ATM-Asynchronous Transfer Mode—A standardized digital data transmission technology that is a cell-based switching technique which uses asynchronous time division multiplexing. This is the core protocol used over the SONET/SDH backbone of the ISDN (Integrated Services Digital Network).
Atmos®—Dolby Atmos is a new audio format for creating and playing back multichannel movie soundtracks. It was developed to give movie sound a more three-dimensional effect. Traditional 5.1- and 7.1-channel surround setups deliver captivating sound using speakers placed all around your room. Dolby Atmos takes this to another level with speakers to create a "height" layer of sound above the listener. Recommend setups include a Dolby Atmos enabled sound bar, 5.1.2, or 7.1.2.
ATSC-Advanced Television Systems Committee—The ATSC was formed to establish voluntary technical standards for advanced television systems, including digital high definition television (HDTV). The ATSC is supported by its members, who are subject to certain qualification requirements.
Attenuate/Attenuation—To reduce the amplitude (strength) or current of a signal.
Attenuation—In fiber optics, this is the loss of optical power as light passes through a fiber optic path. This loss can occur due to absorption, scattering, and excessive bending within the fiber, and can also be attributed to optical components such as connectors, splices, and splitters. Attenuation is usually expressed in dB/km.
ATV-Advanced Television—A digital television system comprising standard, enhanced and high-definition versions.
Audience Response Systems—Audience responses systems are devices that tabulate results when presenters ask questions & audience members to respond or vote by pushing buttons.
Audio—Of or concerning the electronic transmission of sound, specifically the electrical currents representing a sound. (CF. Sound)
Audio Bandwidth—The range of audio frequencies over which an amplifier or receiver will respond and provide useful output. The higher the audio bandwidth the better the sound quality. The highest practical frequency for the human ear is 20 kHz. An audio amplifier delivering a flat response of up to 20 kHz will faithfully reproduce the audio soundtrack of a video recording.
Audio Dub—A feature used in video editing* to add, replace, or mix audio signals with the original sound track without affecting the picture (video portion). Special controls and connectors are available for this purpose on some quality video recorders. When dubbing is not available on, or is limited by, the video recorder, audio dubbing can be performed externally using audio/video processors.
Audio Editing—Combining audio material of different origin into one continuous piece. For example, when a sound track is added to a videotape, various background sounds, music and speech may be supplemented in order to highlight particular scenes in a movie. Audio correction can also be done during video editing. Audio equalization*, audio noise reduction*, Dolby* encoding, etc. are functions available on many quality editors.
Audio Equalization—An audio process, hardware or software based, which breaks down the audio spectrum into several frequency bands to compensate for changes in audio frequency-dependent levels, allowing the user to control (boost or cut) each frequency segment individually. The main use of audio equalizers is to compensate for inadequate acoustics in the room where the sound is being played. Another very important use for audio equalization is to revitalize the playback* characteristics of low quality tapes and poor recordings in order to recreate the original sound.
Audio Exciter—An audio circuit available in high quality audio equipment, designed to recreate the harmonic content of an audio signal which was lost during video or audio tape duplication. Using the audio exciter to recreate the lost harmonic content, generates a sparkling audio sound. This effect is different from normal high frequency boosting which generates noise* and hiss* while improving the frequency response of the audio signal. Audio exciting is available only on special sound correction devices.
Audio Follow—A term used when audio is tied to other signals, such as video, and they are switched together. The opposite of “breakaway.”
Audio-Follow-Video Switcher—During video production, the video signal is normally accompanied by an audio signal. Sometimes, during the switching or processing of signals, the audio signal is separated from the video signal. In such a case, a complex situation arises whereby each signal must be processed, mixed and enhanced separately. Audio-follow-video is a process which overcomes this difficulty and both signals, audio and video, are switched from an audio-video source to an audio-video acceptor simultaneously (not in separate passes).
Audio Frequency—Frequencies within the range of human hearing, about 20 Hz to 20 kHz.
Audio Mixing—The mixing or blending of two or more audio signals to generate a new signal, which is often used for audio dubbing*. Audio mixing requires that all audio channels involved are amplified and equalized to the same level. To mix a line level input with a microphone signal, the microphone signal must be pre-amplified to bring it up to a level similar to that of the line signal. In video processing, audio mixing is used for the insertion of background music behind the dialogue. It is also employed in the creation of cross fading* between two audio sources. It produces a drift in the level of the received signals until one fades out and the second becomes dominant.
Audio Noise—A hiss* (random high frequency noise) or a hum (low frequency noise from the power-line frequency and its harmonics or ground loops) heard on audio or video equipment. It is the result of poor signal handling or of discrepancies between audio pickup devices and media. Audio noise reduction* circuitry eliminates or reduces audio noise.
Audio Path—Describes the complete path that audio travels. Any and all changes to the signal are listed in the order that they are performed. If no changes are made to the signal and a high-quality output is used, the output will be called 'Direct'.
Audio Processor—An electronic device used to manipulate audio signals in some manner.
Audio Signal—An electrical representation of sound.
Audio Summing Amplifier—A device that converts two-channel stereo audio signals into balanced/unbalanced one-channel mono audio signals.
Audio Transduction—Converting acoustical energy into electrical energy, or electrical energy back into acoustical energy.
Audio Video—A term which was often used when discussing a channel on a TV receiver or on video equipment, which has been especially designed to accept VCR audio-video signals. This channel automatically activates special circuitry within the TV set or monitor to prevent picture distortion* and skewing*. It is also used for audio-video processors, which handle both types of signals. The AV definition (Audio-Video) has broadened since then and now describes anything that handles both signals simultaneously.
Audio Video Combiner—A device which combines audio and video signals. In the analog world it describes a machine, which modulates the audio signal on a high frequency carrier and mixes it with the video signal for transmission on a single cable. In the digital world it describes a device which embeds digital audio signals within a digital video signal.
Auto-Focus-Automatic Focus—A device in a projector or camera that uses light reflected from a surface to focus the image.
Auto-Image™—An Extron technology for scan converters and signal processors that simplifies setup by executing image sizing, centering, and filtering adjustments with a single button push.
Auto-Input Switching—The feature that enables a product to detect which input has an active sync signal and switch to that input.
Automatic Convergence—The automatic alignment of the red, green, and blue color images on a screen.
Automatic Noise Gate—A unique feature, available only on Kramer equipment, which provides optimal automatic suppression of snow* (signal noise level) during any stage of video enhancement* (See Noise Gate.)
Automatic Sync Stripping—The automatic removal of sync signals from video channels. Typically, this is associated with removing the sync signal from the green channel, but it may apply to stripping the sync from all three video channels (Red, Green, and Blue).
Autosizing—Automatic picture sizing adjustment to compensate for different display modes, thus enabling the display system to center the picture and fill the screen.
Autoswitching—The feature that enables a product to detect which input has an active sync signal and switch to that input.
AV—Audio visual, or audio video.
AV3—A Crestron, rack-mountable 3-Series® control processor offering immense power, expanded memory, numerous integrated control ports and optional control card expansion slots. Features an isolated control subnet providing a Gigabit Ethernet LAN dedicated for Crestron devices.
AV/C-Audio-Video Control—A simple FireWire-based technology for controlling the components in a home-theater system as a single unit with one remote control.
AVI-Audio Video Interleaved—A computer video/graphics format. This format interleaves digitized video frames (or computer-generated frames) and synchronized audio in one file. The clips generated in the AVI format may be played back in a Windows® equipped PC, usually independent of screen resolution and color palette. This also denotes a practically uncompressed file format obtained for example in a PC, when digital or analog video and audio are captured from an external source. As it is uncompressed, it can occupy up to 200 MB of disk space for every minute of captured video.
A/V Input—An input on an A/V receiver or controller that includes both audio and video jacks.
A/V Loop—An A/V input and A/V output pair found on all A/V receivers and controllers. Used to connect a component that records as well as plays back audio and video signals. A DVD recorder is connected to a receiver’s or controller’s A/V loop.
A/V Preamplifier—Also called by its more descriptive name of an “A/V controller,” the A/V preamplifier is a component that performs surround decoding and lets you control the playback volume and select which source you want to watch and listen to.
A/V Preamplifier/Tuner—An A/V preamplifier that includes, in the same chassis, an AM and/or FM tuner for receiving radio broadcasts.
A/V Receiver—The central component of a home-theater system; receives signals from source components, selects which signal you watch and listen to, controls the playback volume, performs surround decoding, receives radio broadcasts, and amplifies signals to drive a home-theater loudspeaker system. Also called a “surround receiver.”
Avalanche Photodiode-APD—A type of photodiode, or optical signal transducer that converts light to an electrical signal, used in fiber optic receivers.