GLOSSARY OF TERMS


24 bit color - Computer graphics system where each pixel can have 256 levels of red, 256 levels of green, and 256 levels of blue simultaneously, allowing each pixel to be any of over 16+ million colors (256x256x256).

A/B switch - An electronic or manual switch which selects either the signal from cable A or the signal from cable B and feeds the signal to a TV, VCR, or other destination.

AC Adapter - Device that connects to a wall electrical outlet (AC), and sends power to a device to: charge its batteries, or operate without using battery power.

Adapter - A connector which allows one type of plug to fit into another type of socket.

Analog - A signal that varies continuously as opposed to a digital signal made of discrete levels. Analog circuits can suffer from noise and distortion. Phonograph records and tapes are examples of analog signals. CDs / Compact Discs use digital signals.

Analog-to-digital (A-to-D) converter - A circuit that samples an analog signal and outputs the information as digital data.

Anti flicker switch or flicker filter -  A feature on some scan converters that processes fine lines in computer graphics so that they don't flicker when displayed as interlaced video on a TV. 

Artifacts - Undesirable elements or defects in a video picture, such as dots crawling along the edge of colored graphics, or color rainbows around shirts with stripes or herringbones. An artifact is some physical disruption of the image.

Aspect Ratio - The shape of a TV screen expressed as width divided by its height. Common TV screens have a 4:3 aspect ratio. High Definition HDTV screens have a 16:9 aspect ratio (a wider image).

ATSC - Advanced Television Systems Committee, a group formed to study DTV and make recommendations to the FCC.

AV - AV stands for Audio Video

Bandwidth - The range of signal frequencies that a piece of audio or video equipment can encode or decode; the difference between the limiting frequencies of a continuous frequency band. Video uses higher frequency that audio, thus requires a wider bandwidth.

BNC - A popular industrial connector used for video or sync. Sometimes used for RF.

Brightness - In color video, the characteristics that makes pictures appear to be most intense, created by luminosity; also the quality of being filled with light.

CATV - An abbreviated term for Community Antenna Television, now generally regarded as "cable TV".

Chroma - The video signal contains two pieces that make up what you see on the screen: the black and white (luma) part, and the color part. Short for chrominance, chroma is the color component of the video signal.

Coax or Coaxial Cable - Stiff, round wire about 1/4 inch in diameter, used to carry video, sync, or RF (antenna) signals. Coaxial cable, sometimes called RF Cable, is an electrical cable used mostly for transmission of video signals. Due to its low signal loss, long lengths of this cable can be used before any signal loss causes a drop in picture quality. The connectors on each end of the cable are called RF Connectors.

Codec - Abbreviation of Coder-Decoder. An electronic device or software used to compress and decompress video.

Component Video - Easily confused with the similar sounding "Composite Video," a Component Video connection involves a set of 3 cables: 2 cables to handle the color (aka chrominance) and 1 to handle the brightness (aka luminance). Component Video cables are color coded (red, green and blue) for easy identification when hooking up your components. Component connections are found on most DVD players and HDTV's and on mid- to upper-level AV receivers. Generally superior quality to S-video, but not quite as good as DVI or HDMI.

Composite Video - A video stream that combines red, green, blue, and synchronization signals into one so that it requires only one connector and/or connection. Composite video is employed by most television systems (e.g., NTSC, PAL) and VCRs.  Unlike Component video's 3-cable method, Composite video is a single cable, typically color coded yellow for easy differentiation from similar looking audio cables. Composite video cables are designed specifically to handle video signals. Composite video does a capable job of delivering a good picture via a single cable, but there are several higher quality choices. Also means color video carried on one wire with the colors combined (encoded) with the brightness constituents of the picture.

Compression - To reduce the size of audio or video data through the use of compression. Also called encode.  The process of electronically processing audio or video signals so that it requires less storage on a computer hard drive. A 5:1 compression requires more storage space, but has better quality than a 10:1 compression. Higher compression ratio means a smaller file size but also less quality.

CRT - Cathode Ray Tube (CRT). The heavy glass picture tube used in most TVs and computer monitors. These are quickly being phased out in favor of LCD and Plasma displays.

Digital zoom - An electronic way of blowing up a picture making it look larger.

Distribution Amplifier - A device which splits and amplifies an audio and/or video source signal to several audio/video outputs. Used to duplicate one videotape to any number of VCRs with minimal loss of signal strength..

DRM - (Digital Rights Management) Short for digital rights management, a system for protecting the copyrights of data circulated via the Internet or other digital media by enabling secure distribution and/or disabling illegal distribution of the data. Typically, a DRM system protects intellectual property by either encrypting the data so that it can only be accessed by authorized users or marking the content with a digital watermark or similar method so that the content can not be freely distributed.

DTV - Digital Television, TV that is broadcast, recorded, and processed digitally, possibly with extended definition like HDTV.

DVI - (Digital Video Interface) - DVI is one of the best methods for delivering video digitally and is available on most HDTV tuners and HDTV-ready televisions as well as on many DVD players, mid- to upper-level AV receivers and newer computer monitors. DVI is an encrypted format so you can't record a signal delivered via DVI. However, you can use DVI for your TV and an analog video format (such as component video or S-video) to record to a DVR (such as Tivo®) or DVD recorder.

DVR - Digital Video Recorder. A VCR or computer disk recorder that records/plays digits representing audio and video.

F-Connector - The standard connector used with coaxial cable and the RF inputs/outputs of most video equipment.

Flic-Free - AITech's Flic-Free™ filter optimizes the video signal to produce a clear and stable TV image.

Gigahertz (GHz) - One billion Hertz (Hz) or one billion cycles per second. Many wireless transmitters and receivers that send video and wireless computer networking equipment operate on the 2.4 GHz frequency.

HDCP - (High-bandwidth Digital Content Protection) A form of digital copy protection developed by Intel Corporation to protect digital audio and video content as it travels across HDMI and DVI connections. Pre-2005 HDMI and DVI formats displayed HD resolutions but without any digital protection. HDMI and DVI Plasma, LCD TVs, monitors and projectors that do not have HDCP support (all models pre 2005) will not be able to display HDCP material.

HDMI - (High Definition Multimedia Interface) - HDMI is the current state-of-the-art in delivering the highest quality video and audio through a single cable. HDMI can send high definition video (HDTV) as well as surround sound. Most recent HDTV television and mid- to upper-end home theater receivers and DVD players offer HDMI connections. HDMI is also compatible with most DVI connections for video so if you have, say a DVD player with DVI output and a plasma TV with HDMI input, you can use an HDMI-to-DVI cable to connect them, although you will need a separate connection for the audio, such as optical digital or coaxial digital. HDMI is an encrypted format so you can't record a signal delivered via HDMI. However, you can use HDMI for your TV and an analog video format (such as component video or S-video) to record to a DVR (such as Tivo®) or DVD recorder.

HDTV - (High-Definition Television) - Method of displaying sharper, wider TV pictures than the present NTSC system. Pictures are 16:9 aspect ratio, composed of 1,125 scanning lines, each line having 1,920 pixels.

Horizontal Resolution - The number of vertical black and white lines that can be defined, as measured along a horizontal line.

IC - Integrated Circuit

Interlace - The manner in which a television picture is composed, scanning alternate lines to produce one field, approximately every 1/60 of a second in NTSC. Two fields comprise one television frame resulting in the NTSC television frame rate of approximately 30 fps.

Interlaced - In a television display, interlaced scan refers to the process of re-assembling a picture from a series of video signals. The "standard" NTSC system uses 525 scanning lines to create a picture (frame). The frame/picture is made up of two fields: The first field has 262.5 odd lines (1,3,5...) and the second field has 262.5 even lines (2,4,6...). The odd lines are scanned (drawn on the screen) in 1/60th of a second, and the even lines follow in the next 1/60th of a second. This presents an entire frame/picture of 525 lines in 1/30th of a second. Why did the founding fathers of video decide to go with an interlaced system? It has to do with frame rate. A large TV screen that was updated at 30 frames per second would flicker, meaning that the image would begin to fade away before the next one was drawn on the screen. By using two fields, each containing one-half of the information that makes up the frame and each field being drawn on the screen consecutively, the field update rate is 60 fields per second. At this update rate, the eye blends everything together into a smooth, continuous motion.  Analog NTSC video uses interlaced scanning, as do several digital television formats. Formats that include an "i" (1080i, 480i) use interlaced scanning. See also progressive scan.

IR - Abbreviated as IR, infrared is a wave of light that in the area beyond the visible part of the color spectrum. Wireless remote controls for TVs and other electronic devices use IR to send commands from the remote to the TV.

Jitter - Short-term variations in the characteristics (such as frequency, amplitude, etc.) of a signal.

LCD - A liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector.

Line doubler - Device that doubles the scan lines that makes a picture, essentially placing lines between lines, improving the look of video when shown on computer-like devices such as computer projectors.

Luminance - The term is used to denote the brightness or black-and-white picture of a video image.

Mini phono jacks - Used on devices like mp3 players and computer sound cards. Computer speakers and computer sound cards also use these audio jacks. They are sometimes called mini-phono plugs or 3.5mm jacks

Macrovision - An anti-copy signal recorded on a video tape to make it playable but not copyable.

Monitor - A video display. A monitor is like a TV except it lacks the ability to tune in channels. A monitor may or may not have a sound amplifier and speaker.

Monochrome - Black and white video. A video signal that represents the brightness values (luminance) in the picture, but not the color values (chrominance).

MPEG - The term refers to the family of digital video compression standards and file formats developed by the Moving Picture Experts Group. MP3, MPEG-2 and MPEG-4 are common forms of MPEG compression.

Multimedia - Audio, video, text, graphics, and other information delivered by computer.

Noise - Unwanted disturbance within an electronic system. Interference present in a video picture.

Non-interlaced - This is a method of scanning out a video display that is the total opposite of interlaced. All of the lines in the frame are scanned out sequentially, one right after the other. The term field does not apply in a noninterlaced system. Another term for a noninterlaced system is progressive scan.

NTSC - A TV Standard. National Television Standards Committee. A group of businesses and engineers originally created to decide on early standards for color and black-and-white televisions in the U.S.. The NTSC system is also used in Japan. Other television standards around the world include PAL (most of Europe) and SECAM (France, parts of Africa and Russia).

Overscan - A technique used in consumer display products that extends the deflection of a CRT's electron beam beyond the physical boundaries of the screen to ensure that images will always fill the display area. (A TV picture blown up too big on the screen, causing the edges of the picture to be cut off and hidden from view)  When converting computer screen to overscan, graphics and text at the edges of the image may be lost.  See also underscan.

PAL - A TV Standard. Phase Alternate Line is the 625-line color video system currently used in most of Western Europe, England, Australia, and South Africa. Incompatible with the U.S. NTSC system.

PCI - Peripheral Component Interconnect, a very fast pathway for data traveling from one board to another in the computer. PCI video cards require little configuration (plug-and-play) in order to work.

Pixel - Short for Picture Element, a pixel is a single point in a graphic image. Graphics monitors display pictures by dividing the display screen into thousands (or millions) of pixels, arranged in rows and columns. The pixels are so close together that they appear connected.

Plasma Display - A plasma display panel (PDP) is a type of flat panel display now commonly used for large TV displays (typically above 32"). Many tiny cells located between two panels of glass hold an inert mixture of noble gases (neon and xenon). The gas in the cells is electrically turned into a plasma which then excites phosphors to emit light. It is often used in the home environment and is becoming increasingly popular in modern cultures.

Power Supply / Power Adapter - Circuit in electronic equipment which converts household electricity to the kind of power (correct voltage and frequency) the equipment needs in order to run.

Progressive scan - Some digital television broadcast formats (1080p, 720p, 480p), and some higher-end DVD players, use a type of video signal known as progressive scan. Instead of splitting each video frame into two sequential fields like standard interlaced NTSC video, progressive-scan video displays the entire frame in a single sweep. So, where standard NTSC video displays 30 frames (60 fields) per second, progressive scan displays 60 full frames per second.   Displaying progressive-scan video requires more bandwidth (there's twice as much vertical information) and a faster horizontal scan frequency than interlaced video. Progressive-scan picture quality is more film-like, with more fine detail and less flicker. For progressive-scan viewing, you'll need a TV that's HDTV-ready.

PS/2 - The PS/2 connector is used for connecting a keyboard and a mouse to a PC compatible computer system.

Radio frequency interference / RF interference - Typically experienced as "snow" in a TV screen or "pops" in your speakers, there are numerous sources of radio interference. Some sources are nearby like CB or Ham radios, or cell phones. Other sources can be far away like radio stations, microwave towers and the like.

RCA Connector or Phono Plug - Small connector used to carry analog audio signals and, in home video equipment, video signals and sometimes RF signals. While there are higher quality types of audio connections available, older devices often only offer RCA jacks.

Refresh Rate - The refresh rate (most commonly the "vertical refresh rate", "vertical scan rate" for CRTs) is the number of times in a second that display hardware draws the data it is being given.

Resolution - The clarity or sharpness of the picture. Resolution is most often stated in the number of total lines or pixels that make up an image.

RF coaxial  - Also known as "75 ohm input" or simply "coaxial input," this is the basic connector for hooking up antennas, cable boxes, VCRs and TVs. This connector carries both video and audio (though only stereo, not surround sound).

RF Modulator - Electronic device which combines audio and video signals, coding them into RF, a TV channel number.

RGB - Red, Green, and Blue are the three additive colors used for TV and computer monitor signals. .

Saturation - The strength or amount of a certain color present in a television picture; saturation is expressed as the purity of the color.

Scaling - Scaling is the act of changing the effective resolution of the image. For example, let's take a TV size resolution of 640x480 and display that image as a smaller picture on the same screen, so that multiple pictures can be shown simultaneously. We could scale the original image down to a resolution of 320x240, which is 1/4 of the original size. Now, four pictures can be shown at the same time. That was an example of "scaling down." Scaling up is what occurs when a snapshot is enlarged into an 8"x 10" glossy. There are many different methods for image scaling, and some " look" better than others. In general, though, the better the algorithm "looks," the harder or more expensive it is to implement.

Scan Converter - Electronic device that changes the signals that a computer sends to its monitor, into video signals that can be displayed on a TV monitor or recorded on a VCR.

SCART - This is a 21-pin connector supported by many consumer audio/video components in Europe. It allows mono or stereo audio, composite video, S-video, and RGB video to be transmitted between equipment.

SDTV - Standard Definition Television, digitally broadcast TV signals with about the same sharpness and screen shape as today's NTSC television.

SECAM - A TV Standard. Sequential Color And Memory---a video standard used in much of Asia, incompatible with our NTSC system.

S-Video - Separated Video, also called Y/C video. A type of video signal. S-Video transmits luminance and color portions separately, using multiple wires, thus avoiding the color encoding process and its inevitable loss of picture quality. The format uses a 4-pin din cable to carry the separated signals, chrominance and luminance, versus the composite type that combines the signal over one wire. Virtually all DVD players, most satellite receivers and AV receivers and most newer TVs have S-video connections. In the "Good-Better-Best" scenario of choices, S-video is somewhere between 'Good' and 'Better.' Utilizing a round, 4-pin connector, S-video provides better picture quality than RF Coaxial or Composite video, but not as good as Component video or the two digital formats, DVI and HDMI.

Scaling - Scaling is the act of changing the effective resolution of the image. For example, let's take a TV size resolution of 640x480 and display that image as a smaller picture on the same screen, so that multiple pictures can be shown simultaneously. We could scale the original image down to a resolution of 320x240, which is 1/4 of the original size. Now, four pictures can be shown at the same time. That was an example of "scaling down." Scaling up is what occurs when a snapshot is enlarged into an 8"x 10" glossy. There are many different methods for image scaling, and some " look" better than others. In general, though, the better the algorithm "looks," the harder or more expensive it is to implement.

Streaming Media - Internet video and/or audio clips that can play directly over the Internet, without needing to be downloaded first onto a computer. Used to view and hear broadcasts, and to interactively play and seek in stored clips.

TV Standard - Set of technical specifications describing how a TV picture is made. In the USA, the FCC (Federal Communications Committee) ordained the NTSC (National Television Standards Committee) standard. In Europe, they use a different, incompatible standard, PAL.

UL - UL stands for Underwriters Laboratories Inc., an independent, non-profit, product safety testing and certification organization in the United States. Since 1894, UL has been one of the leaders in testing products for public safety. If a product is UL listed, it has been tested and approved by the laboratory.

Underscan - A technique generally used by some TV and video systems as a way of ensuring that the complete image is always visible within a display area. TV picture which is smaller than the screen, showing the black edges of the picture on the screen.  Most televisions use overscanning.  Underscanning modifies the video timing so that the entire video signal appears in a rectangle centered on the television screen with a black border. The resolutions for square-pixel underscan and overscan images are:
NTSC overscan: 640 x 480
NTSC underscan: 512 x 384
PAL overscan: 768 x 576
PAL underscan: 640 x 480

USB - (Universal Serial Bus) ports are on virtually every PC and Mac made in the past 5 years. A USB connection is often used to connect flash drives, digital cameras, mp3 players and other portable A/V devices to a computer. There are a few types of USB connectors. The USB Type A connector plugs into the USB port on your computer. The USB Type B connector plugs into a peripheral device (such as a monitor or printer). Compact devices like cameras and mp3 players typically have smaller USB jacks called a mini USB. All USB cables have a Type A connector on one end (for the computer) and either a Type B or mini USB connector on the other end.

VGA - Also sometimes referred to as RGB (D-sub 15-pin), VGA cables are used to connect a computer to a projector, computer monitor, scan converter, plasma TV, LCD TV or other digital flat panel TV's. VGA provides high quality analog video by separating the video signal into 3 parts which allows for exceptionally clear and bright images.
VGA Monitor - A monitor capable of displaying a VGA signal. Can be either CRT, LCD, Plasma.
Video Card or Video Adapter - Sometimes also called a VGA Card, this is the device inside a laptop or desktop computer that the computer monitor connects to.

Video signal - An electrical signal that includes all of the information present in the television picture together with the necessary synchronizing signals.

VOD - (Video On Demand) High speed Internet connection permitting users to download video (i.e., movies), playing it in real time on their TVs.

VSPro - AITech's patented video signal processing technology, which is used in the AITech's scan conversion products. VSPro is a high-speed, digital signal processing technology. It is implemented in AITech's single chip scan converter products, such as the AIT2138 and AIT1168.

WLAN - (Wireless LAN) A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires.

Y/C Video - See S-Video

YPbPr - Analog video signal carried by component video cable in consumer electronics. Note that the green cable carries Y, the blue cable carries Pb and the red cable carries Pr.

 

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