- Additive colors: The color system that mixes colored light to create all the various colors of the color spectrum.
- Algorithms: Complex mathematical formulas that define digital
- Alternating Current: An electrical circuit through which the
flow of electrons reverses itself from negative to positive, from positive
to negative, and back again at a regular rate.
- Amperes (amps): The unit of measurement for current.
- Analog video signal: The varying voltages that make up the video
information of a television signal.
- Assemble edits: Edits that lay down all aspects of the signal
— audio, video, and control track — all at the same time.
- A to D converter: The circuitry that converts analog signal
information into digital information.
- Audio board: See Audio mixer.
- Audio console: See Audio mixer.
- Audio-follows-video switcher: A switcher that changes both audio
and video sources with the push of one button.
- Audio mixer: An audio device that allows you to bring several
sound sources together, choose among them, mix them together, measure
their strength, and hear them.
- Back porch: The portion of the waveform scan that represents
the horizontal blanking just before the start of a new line of video.
- Balanced audio: A technology used with professional sound equipment
designed to reduce the amount of induced electromagnetic noise in the
- Bandwidth: The amount of space available over the airwaves or
through a cable for carrying information. A signal with more information
requires more bandwidth to carry it.
- Bit: The smallest increment of computer memory represented by
a 0 or a 1.
- Black burst: A signal from the sync generator that includes
all normal blanking and sync information along with black video.
- Blanking: That time when the electron guns in the system are
turned down to a low voltage so that they can return to the beginning
of a new line or field.
- Blanking pulses: Signals from the sync generator that tell the
camera’s electron gun to go into blanking.
- Bus: A row of buttons on a switcher that allows a person to
change between various video sources that are available in the system.
- Byte: The smallest piece of computer memory that can be used
as a distinct piece of information; made up of a group of bits.
- Camera: A device that changes light images into a usable electronic
- Capstan servo: See Vertical lock.
- CCD (charge-coupled device): A solid-state device used instead
of a pickup tube for changing light images into an electronic video signal.
- Character generator (CG): A machine that creates words and titles
for the TV screen.
- Chroma: The color information in a TV signal.
- Chroma key: A special effect in which a chosen color is replaced
with video from another source.
- Chroma key tracking: A digital effect that compresses the signal
from a video source into the available chroma key window.
- CODEC: Stands for code/decode and defines all of the
technical parameters of a digital format.
- Color burst or 3.58: The color reference inserted in every video
line that determines how color information is to be interpreted.
- Color difference component video: A component video system that
saves bandwidth by using a luminance channel (Y), which comes primarily
from the green channel, and two color channels with the luminance removed
(R-Y and B-Y).
- Color subcarrier: See Color burst.
- Color sync: See Color burst.
- Complementary colors: The colors cyan, magenta, and yellow that
are created by mixing parts of the primary colors (red, green, and blue).
- Component switcher: A video switcher that deals with the individual
color components (red, green, and blue) of the picture instead of the
encoded composite video signal.
- Component video: A video signal made up of the individual component
parts as opposed to an encoded composite signal.
- Composite video: The video signal made up of both the video
and sync information.
- Compressions: Digital effects in which the size and/or aspect
of the picture is changed on the TV screen.
- Compression, Spatial: Video compression that takes place within
an individual video frame that contributes to overall bandwidth reduction.
- Compression, Temporal: Video compression that takes place between
successive video frames which helps reduce overall bandwidth needs.
- Compression, Video: Removal of redundant information and encoding
of video in such a way that it can be transmitted and stored using less
bandwidth than uncompressed video.
- Control track: A track on the videotape used to help stabilize
tape playback speed.
- Control track counter editing controller: A device that controls
videotape editing by counting the control track pulses on the tapes.
- CRT (cathode ray tube): Television picture tube.
- Current: The volume of electrons passing a given point at a
given time, measured in amps.
- DA (distribution amplifier): A piece of equipment that produces
multiple outputs identical to its input signal.
- DAT (digital audiotape): Equipment that uses a small audiocassette
and a recording head mounted on a spinning drum that moves in the opposite
direction to the tape.
- Dedicated equipment: Video equipment designed for a specific purpose,
such as switchers, edit controllers, and character generators.
- Deflection yoke: Electromagnetic coils around a CRT used to
steer the CRT’s electron beam as it sprays the picture across the screen.
- Desktop video: The concept of private individuals being able
to do low-cost, high-quality video production using production equipment
based on the personal computer.
- Digital audio workstation (DAW): A computer system with specialized
software and possibly hardware that allows the computer to record, edit,
and process multiple audio tracks into a finished sound product.
- Digital encoding ratios: A ratio that indicates the relationship
between the amount of luminance (Y), and chrominance (B-Y and R-Y). Information
is contained in a digital signal, for example, 4:2:2 or 4:1:1.
- Digital video: video signal that is made up of a series of assigned
numbers rather than analog voltages.
- Direct current: An electrical circuit through which the flow
of electrons moves in only one direction.
- Disc-based recorders: Video recorders that use either magnetic
discs like computer hard drives or optical discs like DVDs in place of
videotape for recording.
- Drive pulses: Signals from the sync generator that control the scanning
of the electron beams.
- D to A converter: Circuitry that converts digital information
into analog information.
- Drop frame: When set in the drop frame mode SMPTE time code
will consistently skip a number in the sequence. Since time code normally
counts 30 frames a second when video really only has 29.97 frames a second,
this is necessary so that the time code can be consistent with the real
time on a clock.
- Dubbing: The process of copying the electronic signal from one
tape to another.
- Dynamic tracking head: A videotape head that automatically aligns
itself with the center of the video track on the tape for slow motion
or freeze frames.
- EDL or edit decision list: Editing script that includes SMPTE time
code start and stop points, running time, and transition types. It is
usually put together during the oft-line editing process.
- Electronic palette: A rectangular surface that represents the
“paper” in a computer graphics system.
- Encoding: The process of combining the chroma and luminance
information into a single signal.
- Fields: The complete set of odd- or even-numbered lines that,
when interlaced, make up one video frame.
- 5.1 sound: A surround sound system that has been accepted as
part of the HDTV standard for the United States.
- Flow diagrams: A diagram that uses geometric shapes and lines
in place of equipment and wires to illustrate the interconnection of
- Fonts: The style of a particular typeface that is used on a
- Frame: In the U.S. system, two interlaced fields of 262.5 lines
each, which, when combined, make a complete picture of 525 lines. There
are 30 frames per second in the NTSC (American) system.
- Frame lock: A method of stabilizing videotape playback that
tries to match an even field of the playback signal to an even field
coming from the sync generator, and an odd field of the playback signal
to an odd field coming from the sync generator.
- Frame store synchronizer (frame synchronizer): A device used
to lock up non-synchronous video signals to the main system.
- Front porch: The portion of the waveform scan that represents
the horizontal blanking at the end of a line of video.
- Giga (G): The abbreviation for billions (1,000,000,000). For
example, 6 GHz would equal 6,000,000,000 Hz.
- Gyroscopic time base error: Time base error that is created
when a videotape recorder is moved perpendicular to the plane of the
head drum’s rotation.
- HDTV: High-definition TV.
- Head: The small electromagnetic device that lays down or picks
up the information on a piece of recording tape.
- Headwheel: The rotating disc on which the video heads are mounted.
- Helical: A method of video recording that lays down video information
at a slant to the tape’s direction of travel; also known as slant track
- Hertz (Hz): A measurement of frequency equal to one cycle per
- Horizontal blanking: The period extending from the time the
electron guns are turned down to a low voltage at the end of a line until
they are turned back up at the beginning of a new line.
- Horizontal lock: A method of stabilizing videotape playback
that tries to match a horizontal sync pulse of the playback signal to
each horizontal sync pulse coming from the sync generator.
- Horizontal sync: The signal from the sync generator that causes
the electron gun to return to the other side of the screen for a new
- Impedance: A measurement of the properties that tell whether
two or more circuits will interact well — measured in ohms.
- Induction: The process in which a circuit with a stronger magnetic
field forces some of its signal into a circuit with a weaker magnetic
- Insert edits: Edits that use control tracks that have already
been laid down on the tape.
- Interlace scanning: The process of taking a field of odd-numbered
lines (1, 3, 5, 7, . . .) and combining it with a field of even-numbered
lines (2, 4, 6, 8, . . .) to make a complete video frame (525).
- Interpolation: The mathematical process of creating new video
information (pixels) from surrounding information.
- Keys: A special effect in which the signal from one video source
“cuts” a hole into another video source.
- Kilo (K): The abbreviation for thousand (5 K = 5000).
- LCD (liquid crystal display): A flat-screen monitor where liquid
crystals control light to create a picture.
- Linear editing: The traditional method of videotape editing
in which one scene is laid down after another on tape. If any changes
are needed after the edits have been made, the rest of the tape will
have to be reedited.
- Linear keys: Keys in which the key hole is not cut entirely
through the background video, allowing that video to be seen through
the overlying key.
- Loudspeaker: An audio transducer that changes analog voltages
- Luminance: The black and white portion of the video signal.
- Luminance keys: Keys in which the hole being cut is determined
by the brightness of the video source.
- Manual editing: Editing that is performed completely by a person
without using an electronic editing controller.
- Matte key: A luminance key whereby the “hole” created by the
key is filled with artificially created color from the switcher.
- Mega (M): The abbreviation for million (3 M= 3,000,000).
- Micro (p.): The abbreviation for millionth (5 5/1,000,000).
- Microphone: An audio transducer that changes sound into analog
- Mull (m): The abbreviation for thousandth (200 m = 200/1000).
Mismatch Refers to impedance in which two pieces of equipment will not
work well together.
- Monitor: A TV set designed to display a straight video signal
as opposed to a set designed to receive programs off the air.
- Mono or monaural sound: Sound where the entire sonic message
is recorded on one channel and played through one speaker.
- MPEG 2 (Moving Picture Experts Group 2): The most commonly used
professional video compression standard.
- Nano (n): The abbreviation for billionth (5 n = 5/1,000,000,000).
- Noise: Unwanted electromagnetic static inherent in all electronic
- Non-composite video: Video information without sync information.
- Nonlinear editing: A method in which video information is recorded
into a digital memory where it can be called up a piece at a time in
any order desired. Changes can be made in the edited program without
reediting the entire show.
- Non-synchronous: A signal that is completely out of sync with
the main system.
- NTSC: The system of color television used in the United States
and other parts of the world. The system uses 525 scanning lines and
60 fields with 30 frames per second. (The field and frame rates have
been rounded off.) The name comes from the National Television Systems
Committee, which was a group of industry experts who developed and proposed
the system to the Federal Communications Commission in the early 1950s.
- Off-line editing: The process of developing an editing script
made up of SMPTE code numbers and a work print on small-format helical
- Ohm: The unit of measurement for both resistance and impedance.
- On-air switcher: The switcher used to determine what goes to
the transmitter; usually an audio-follows-video switcher.
- On-line editing: The process of editing the final, finished
tape on large-format tape machines.
- Open architecture: The concept of using computers with highly
spe cialized programs to replace traditional dedicated equipment. Hence,
a computer could be a time base corrector, edit controller, video switcher,
digital effects unit, and character generator, all in one.
- Out of phase: A condition that occurs when cameras show different
colors during a transition because their color bursts are not matched.
- Oxides: The coating on tape that allows signals to be recorded
- Pages: In a character generator or computer graphics system,
one full screen of information that can be displayed at a time.
- PAL (Phase Alternate Lines): A color television system that
was designed in Germany to overcome some of the problems of NTSC; it
uses 625 scanning lines with 50 fields and 25 frames per second. This
system is used in Western Europe and many other parts of the world.
- PAL-M: A color television system that is the same as PAL except
that it is designed for countries that use a 60-Hz frequency for their
AC power supply and therefore has 60 fields and 30 frames per second.
- Patch panel: A device that allows flexible routing of signals
from one place to another.
- Pedestal: The black portions or areas of the TV picture. Pixel
- Plasma display screen: A video display device that uses electrically
charged gases (plasma) to activate color pixels.
- Primary colors: In television, the colors red, green, and blue.
- Proc amp: Video processing amplifier, a piece of equipment that
strips the distorted sync from a videotape playback signal and replaces
it with clean sync. Most proc amps also allow the control of some of
the video parameters, such as hue, video brightness, and pedestal (black)
- Progressive scanning: This is when a CAT electron gun scans
the picture from top to bottom in numerical order; lines 1, 2, 3, 4,
- Quantizing: The process of converting a sample of video information
into a number.
- Resistance: A measurement in ohms indicating the constraint
to the flow of electricity.
- Routing switcher: A switcher used to route signals from one
place to another.
- Sampling: The process of “grabbing” a piece of analog video
information so that it can be quantized, or converted into numbers, for
either processing or storage in memory.
- SDTV (standard definition digital television): The digital equal
to the analog color standard that has been in use for decades; what you
get with the mini-dish satellite or digital cable systems.
- Self-fill key: A luminance key in which the hole cut is filled
by the video that cut the hole.
- Signal-to-noise ratio: A comparison of the strength of the signal
coming out of a piece of equipment to the internal noise created by that
- SMPTE, Society of Motion Picture and Television Engineers: This
is the professional organization of electrical engineers that focuses
on motion picture and broadcast technology.
- SMPTE time code: A digital code laid down on tape that gives
each frame of video a unique and unchanging address (03:38:52:04 would
equal 3 hours, 38 minutes, 52 seconds, and 4 frames).
- Software: Computer programming that tells the computer how to
- Stereo or stereophonic sound: Sound that is recorded on multiple
channels and played through multiple speakers to give the sense that
sound is coming from different locations.
- Stylus: An electronic device that acts as the pen, pencil, brush,
and the like, in a computer graphics system.
- Surround sound: A type of stereo using speakers all around a
room to give the sense that sound is coming from anywhere in the room.
- Switcher: A device that allows a person to make a transition
between video sources.
- Sync: A signal from the sync generator that causes the electron
guns to return to the beginning of a new video line or field.
- Sync generator: A device that provides various sync signals
(drive pulses, blanking pulses, and sync pulses) to keep all of the equipment
in a video system working together.
- Tape transport system: The mechanical system that pulls tape
through a machine at an even speed.
- Target: The photosensitive coating of a pickup tube.
- TBC (time base corrector): A device for correcting time base
error in videotape playback.
- Time base error: The instability of a videotape playback signal
created by the machine’s inability to play back at exactly the same speed
at which the tape was recorded.
- Transparent key: See Linear keys.
- Unbalanced audio: Audio that does not have the aspects of balanced
audio (see Balanced audio); used on consumer audio equipment.
- Vectorscope: A piece of equipment that shows a graphic display
of the color portion of the video signal.
- Vertical blanking: The period when the electron beam is turned
down at the end of a video field until it is turned back up at the start
of a new field.
- Vertical interval: The period when the electron beam is in vertical
- Vertical interval switcher: A switcher that delays cuts between
video sources until the entire system is in vertical blanking.
- Vertical lock: A method of stabilizing videotape playback that
tries to match the control track pulses of the playback signal to vertical
sync pulses coming from the sync generator; also called capstan servo.
- Vertical sync: The signal from the sync generator that tells
the electron beams to return to the top of the screen for the start of
a new video field.
- Video compression: A technology that allows digital video information
to be compressed into a smaller space, thereby requiring less bandwidth
or memory space for transmission or storage.
- Video servers: Computer-like hard drives specially designed
to record and play back multiple channels of video information.
- Volt: The measurement for the pressure of electricity.
- Voltage: The pressure of electricity, measured in volts.
- VTR (videotape recorder): A machine that records sound and pictures
onto magnetic tape.
- Watt: A measurement of electrical power.
- Waveform monitor: A piece of equipment that shows a graphic
display of the black and white portion of the video signal.
- Window of correction: The amount of time base error a time base
corrector will correct, measured in video lines.
- V/C: V equals the luminance portion, and C equals the chrominance
portion of the video signal. AY/C piece of equipment or system will keep
the components separate as much as possible.