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 TivoŽ) 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 TivoŽ) 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. |