Glossary of Video Terms and Acronyms - Isotest

Video Terms and Acronyms
Glossary
Conditional Jump or Call – Instruction that, when reached in a program,
will cause the computer either to continue with the next instruction in the
original sequence or to transfer control to another instruction, depending
on a predetermined condition.
Conductive Coatings – Coatings that are specially treated to reduce the
coating resistance, and thus prevent the accumulation of static electrical
charge. Untreated, non-conductive coatings may become highly charged,
causing transport, noise, and dust-attraction problems.
Confidence Test – A test to make sure a particular device (such as the
keyboard, mouse, or a drive) is set up and working properly.
CONFIG.SYS – A file that provides the system with information regarding
application requirements. This information may include peripherals that are
connected and require special drivers (such as a mouse). Other information
that might be specified is the number of files that can be open simultaneously,
or the number of disk drives that can be accessed.
Configuration File – A system file that you change to customize the way
your system behaves. Such files are sometimes referred to as customization
files.
Connector – Hardware at the end of a cable that lets you fasten the cable
to an outlet, port, or another connector.
Console Window – The window that appears each time you log in. IRIX
reports all status and error messages to this window.
Constant – A fixed value.
Constant Bit Rate (CBR) – a) Operation where the bit rate is constant
from start to finish of the compressed bit stream. b) A variety of MPEG
video compression where the amount of compression does not change.
c) CBR traffic requires guaranteed levels of service and throughput in
delay-sensitive applications such as audio and video that are digitized and
represented by a continuous bit stream.
Constant Bit Rate Coded Video – A compressed video bit stream with a
constant average bit rate.
Constant Luminance Principle – A rule of composite color television
that any change in color not accompanied by a change in brightness
should not have any effect on the brightness of the image displayed on a
picture tube. The constant luminance principle is generally violated by
existing NTSC encoders and decoders. See also Gamma.
Constant Shading – The simplest shading type is constant. The color of a
constant shaded polygon’s interior pixels is always the same, regardless of
the polygon’s orientation with respect to the viewer and light sources.
Constant shading is useful for creating light sources, for example. With all
other shading types, a polygon changes its shade as it moves.
Constellation Diagram – Way of representing the I and Q components of
QAM or QPSK modulation. The position of the points in the constellation
diagram provides information about distortions in the QAM or QPSK modulator
as well as about distortions after the transmission of digitally coded
signals.
Constructive Solid Geometry (CSG) – This way of modeling builds a
world by combining “primitive” solids such as cubes, spheres, and cones.
The operations that combine these primitives are typically union, intersec-
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tion, and difference. These are called Boolean operations. A CSG database
is called a CSG tree. In the tree, branch points indicate the operations that
take place on the solids that flow into the branch point.
Content – The program content will consist of the sum total of the
essence (video, audio, data, graphics, etc.) and the metadata. Content can
include television programming, data, and executable software.
Content-Based Image Coding – The analysis of an image to recognize
the objects of the scene (e.g., a house, a person, a car, a face, ...). The
objects, once recognized, are coded as parameters to a general object
model (of the house, person, car, face, ...) which is then synthesized (i.e.,
rendered) by the decoder using computer graphic techniques.
Contour Enhancement – A general term usually intended to include both
aperture correction and edge enhancement.
Contouring – Video picture defect due to quantizing at too coarse a level.
The visual effect of this defect is that pictures take on a layered look
somewhat like a geographical contoured map.
Contrast – Contrast describes the difference between the white and black
levels in a video waveform. If there is a large difference between the white
and black picture levels, the image has high contrast. If there is a small
difference between the white and black portions of the picture, the picture
has low contrast and takes on a gray appearance.
Contrast Ratio – a) Related to gamma law and is a measurement of the
maximum range of light to dark objects that a television system can reproduce.
b) The comparison of the brightest part of the screen to the darkest
part of the screen, expressed as a ratio. The maximum contrast ratio for
television production is 30 x 1.
Contribution – A form of signal transmission where the destination is not
the ultimate viewer and where processing (such as electronic matting) is
likely to be applied to the signal before it reaches the ultimate viewer.
Contribution demands higher signal quality than does distribution because
of the processing.
Contribution Quality – The level of quality of a television signal from the
network to its affiliates. For digital television, this is approximately 45 Mbps.
Control Block – Circuits that perform the control functions of the CPU.
They are responsible for decoding instructions and then generating the
internal control signals that perform the operations requested.
Control Bus – Set of control lines in a computer system. Provides the synchronization
and control information necessary to run the system.
Control Menu Box – Located on the upper left corner of all application
windows, document windows, and dialog boxes, it sizes (maximize, minimize,
or restore) or exits the window.
Control Processor Unit/Central Processing Unit (CPU) – a) Circuits
used to generate or alter control signals. b) A card in the frame which controls
overall switcher operation.
Control Program – Sequence of instructions that guide the CPU through
the various operations it must perform. This program is stored permanently
in ROM where it can be accessed by the CPU during operation. Usually this
ROM is located within the microprocessor chip. Same as Microprogram or
Microcode.