frames used in the MPEG-2 signal. These are composed by assessing the difference
between the previous and the next frames in a television picture sequence.
As they contain only predictive information, they do not make up a complete
picture and so have the advantage of taking up much less data than the
I frames. However, to see that original picture requires a whole sequence
of MPEG-2 frames to be decoded.
See also: I frames, P frames, MPEG.
- B-Mode Edit
- An editing method where
the footage is assembled in the order it appears on the source reels. Missing
scenes are left as black holes to be filled in by a later reel. Requires
fewer reel changes and generally results in a faster edit session.
- “Black and White”. Sometimes
erroneously used to mean monochrome.
- B-Y Axis
- The horizontal axis
of a vectorscope viewscreen. B-Y is one of the color difference signals
used in NTSC and is obtained by electrically subtracting the luminance
(Y) signal from the blue (B) component signal.
- Back Porch
- The portion of the
video signal that lies between the rising edge of the horizontal sync pulse
and the start of active video (or the end of horizontal blanking).
The color burst signal sits on the back porch.
- 1. Finance or support
for a film or video project
- 2. Anti-halation Backing:
A dark coating applied to the back of film to reduce halation. It is removed
- 3. Non-Curl Backing:
A transparent coating applied to the opposite side of a film from the emulsion
to prevent curling.
- Schedule event, determined
in advance, which is available to the operator for transmission when the
originally scheduled event cannot be played back due to system failure.
- Backup Source
- Device or system providing
the signal content for a Backup Event.
- Baird, John Logie
- Pioneer of Television Click
Here This will take you to where you can learn more
- A range of frequencies.
- A measure of the resolution
and information-carrying capacity of a system, typically described
as the range of frequencies in which a signal's amplitude will remain
constant. In digital video systems, bandwidth is limited by filters
to a maximum of one-half the sampling frequency to avoid artifacts caused
by aliasing. It is also the maximum amount of data a signal can carry.
In addition, the frequency spectrum occupied by a signal.
- In terms of signal
frequency, the range between the lowest and the highest frequencies used
to transmit a signal from one site to another. Bandwidth is a measure of
an analog signal and is measured in cycles per second. Contemporary units
are Hertz (one cycle equals one Hertz). (1) In video systems, bandwidth
is specified as the highest frequency value because all video systems must
transmit frequencies down to 30 Hz or lower. The greater the bandwidth,
the more information is carried and the higher the potential resolution
of images. In television, bandwidth is usually expressed in MHz. (2) With
digital codec specifications, bandwidth is represented by the number of
bits of information that can be transmitted per second or bps. High-bandwidth
codecs can have bandwidths between 768 Kbps (thousand bits per second)
and 45 Mbps (million bits per second). Low-bandwidth codecs range between
56 Kbps and 384 Kbps.
- A series of short
lines in an optical scan system used to convey information by their varying
width and interval. As it applies to an automation system: Data about the
contents of a cassette, stored on a cassette label as a series of black
vertical lines. The barcode can contain the following data: cassette and
program identification; program start position, duration and title. Barcode
labels are produced and read using a tape preparation system, and may be
used by the system to identify a tape.
- Barcode Reader
A machine that reads barcode labels. After
the barcode is read, the barcode data is
sent to the automation system.
- 1. Places that serve
alcohol and are coincidentally frequented by off duty engineers.
- 2. Abbreviation for
Color Bars (a test signal).
- The transparent, flexible
support, commonly cellulose acetate, on which photographic emulsions are
coated to make photographic film.
- A signaling technique
in which the signal is transmitted in its original form and not changed
by modulation. Local Area Networks as a whole, fall into two categories:
baseband and broadband. Baseband networks are simpler and cheaper; the
entire bandwidth of the LAN cable is used to transmit a single digital
signal. In broadband networks, the capacity of the cable is divided into
channels, which can transmit many simultaneous signals. Broadband networks
may transmit a mixture of digital and analog signals, as will be the case
in hybrid fiber/coax interactive cable television networks.
- Base Memory
- User programmable base
settings for different film and video formats. Memory settings are scene
by scene programmable.
- BAT (Bouquet
- Batch File or BAT
- A file that contains
DOS commands that are executed when the computer or a program first starts
up. Batch file names always end with .BAT.
- Baud rate is a measure of the number of
times per second a signal in a communications channel varies, or makes
a transition between states (states being frequencies, voltage levels,
or phase angles). One baud is one such change. Thus, a 300-baud modem's
signal changes state 300 times each second, while a 600-baud modem's signal
changes state 600 times per second. This does not necessarily mean that
a 300-baud and a 600-baud modem transmit 300 and 600 bits per second. The
number of bauds a modem transmits per second is directly related to the
number of bits that occur each second, but the numbers are not necessarily
- “British Broadcasting
Board System. A computer that allowed users to dial-up and connect from
remote computers and acted as a central meeting place to chat or play games.
The Internet has largely replaced the BBS. BBSes were generally run from
someone's home PC that had a few phone lines hooked up to it.
- Broadcast Control/Operations
Center. The heart of a broadcast facility. Monitors various downlinks
and up-links to satellites. Also where the System Monitor displays the
status of the TCS and its associated external systems.
- BCC Channel
- A group of encoders.
- BCD (Binary
- A coding system in
which each decimal digit from 0 to 9 is represented by four binary (0 or
- BCO (Broadcast
- A measure of voltage,
current, or power gain. One bel is defined as a tenfold increase in power.
If an amplifier increases a signal's power by 10 times, its power gain
is 1 bel or 10 decibels (dB). If power is increased by 100 times, the power
gain is 2 bels or 20 decibels. 3 dB is considered a doubling.
- Bernoulli Devices
- A medium-high-capacity,
disk-storage medium used for digital data storage. Bernoulli disks use
a floppy piece of magnetic material housed in a rigid cassette.
The disks have a storage capacity of about 20 MB and a data-access performance
equivalent to hard drives.
- Bit error rate.
second stage a software program goes through before a final is released.
Software undergoes rigorous testing until it is ready to be released.
- Sony analog component
video tape format. A broadcast quality, 1/2 inch tape, cassette based system.
Now rare, replaced by Betacam SP and Digital Beta.
- Betacam SP
- Sony analog component video tape format.
A broadcast quality, 1/2 inch tape, cassette based system.
- Betacam SX
- Digital video record/playback
format using MPEG-2, 4:2:2 Profile @ Main Level video and implemented in
the Sony DNW series of hybrid (tape/disk) recorders.
- A microphone that
is sensitive to sounds from only two directions.
Pictures or B-pictures or B-frames
- Pictures that use
both future and past pictures as a reference. This technique is termed
prediction. B-pictures provide the most compression. B-pictures
do not propagate coding errors as they are never used as a reference.
- Electrical pulses from
the tachometer of a telecine, used to update the film footage encoder for
each new frame of film being transferred.
- A constant amplitude high frequency signal
added to the signal to be recorded and sent to the record head to improve the
signal to noise ratio and reduce the distortion of
an analogue recording. It helps to achieve a better level of saturation on the
tape’s magnetic particles.
Also a voltage added to the grid of a vacuum tube.
- Bias Trap
- Used to prevent the
bias signal or multiples of this signal, called harmonics, from
entering the sound path. (See Bias).
- See opening billboard
and closing billboard.
- Where a cart machine stores a tape, when
the tape is not used by one of the cart machine's VTRS.
- A base-2 numbering
system using the digits 0 and 1 (as opposed to 10 digits [0 - 9] in the
decimal system). In computer systems, the binary digits are represented
by two different voltages or currents, one corresponding to 0 and the other
corresponding to 1. All computer programs are executed in binary form.
Binary representation requires a greater
number of digits than the base 10 decimal system more commonly used. For
example, the base 10 number 254 is 11111110 in binary. From right to left,
the digits represent 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048,
4096, 8192, 16384, 32768, etc. Each digit is known as a bit.
- The result of a binary multiplication contains
the sum of digits of the original numbers.
- This example multiplies two 8-bit numbers
to produce a 16-bit result.
- 10101111 x 11010100 = 1001000011101100
(In decimal 175 x 212 = 37,100)
See also: Bit, Byte, Digital.
- Binary Coded Decimal
- A coding method for
representing a decimal number as two, four-bit bytes.
- B ISDN
- Broadband integrated
services digital network. See: ISDN.
- Binary digit: the
smallest unit of digital information with a value of 0 or 1. The smallest
element of a digital word. A group of bits, such as 8-bits or 16-bits,
compose a byte. The number of bits in a byte depends upon the processing
system being used. Typical byte sizes are 8, 16, and 32. (See
binary and word).
- Bit Bucket
- Any device capable
of storing digital data-whether it be video, audio or other types of data.
- Bit Budget
- The total amount of
bits available on the media being used. In DVD, the bit budget of a single
sided/single layer DVD5 disk is actually 4.7 GB.
- “Burned In Time Code”.
Time code numbers that are superimposed on the picture, and may viewed
on any monitor or TV.
- Bit Depth
- The number of levels
that a pixel might have, such as 256 with an 8-bit depth or 1,024 with
a 10-bit depth.
- Bit Parallel
- Transmission of digital
video a byte at a time down a multi-conductor cable where each pair of
wires carries a single bit. This standard is covered under SMPTE 125M,
EBU 3267-E, and ITU-R BT.656 (CCIR 656).
- Bit Rate
- The digital equivalent
of bandwidth, bit rate is measured in bits per second. The higher the bit
rate, the more information that can be carried and the higher the bandwidth.
- The rate at which
and 8-by-8 array of pel values or DCT coefficients presenting luminance
or chrominance information.
- Bit Rate Reduction
- See: Compression.
- Bit Serial
- Transmission of digital
video a bit at a time down a single conductor such as coaxial cable. May
also be sent through fiber optics. This standard is covered under ITU-R
BT.656 (CCIR 656).
- Bit Slippage
- 1. Occurs when word
framing is lost in a serial signal so that the relative value of a bit
is incorrect. This is generally reset at the next serial signal (TRS-ID
for composite and EAV/SAV for component). 2. The erroneous reading of a
serial bit stream when the recovered clock phase drifts enough to miss
a bit. 3. A phenomenon that occurs in parallel digital data buses when
one or more bits get out of time in relation to the rest. The result is
erroneous data. Differing cable lengths is the most common cause.
- Bit Stream
- A series of bits transmitted
on a line.
- As applies to audio,
a sound bite. A sound bite is usually a sentence or other short bit
of audio material. Its most frequent use is in news.
- A representation of
images or graphic information that is made up of individual bits
of picture information or pixels (picture elements). Bitmaps
are computer maps of these bits which can be re-created pixel for
pixel when displayed or printed.
- Bitmapped Graphics
- A form of graphics
that is made up of individual bits of picture information or pixels
(picture elements). The graphic consists of a computer map
of these bits which is re-created pixel for pixel when displayed or printed.
- Bits per Pixel
- The number of bits
used to represent the color value of each pixel in a digitized image.
- Bits Per Second
- Bits per second can be obtained by dividing
the a modem's baud rate by the number of changes in state, or bauds, required
to send one bit.
- Video signal set to
a pre-determined level (7.5 IRE units) so that no picture information appears
and the screen is black. Also referred to as pedestal or
the level at which this signal is set determines overall picture contrast
- Black Box
- A term used to describe
a piece of equipment dedicated to one specific function, usually involving
a form of digital video (black) magic.
- Black Burst
- A composite video
signal consisting of composite sync, reference burst and a black video
signal (usually with setup), which is 7.5 IRE (53.5 mV) above blanking
level. Black burst is typically used as a reference signal in video
- Black Crushing
- Loss of low light (shadow) detail caused
by adjusting luminance information below the Black Level.
- Black Level
- In an NTSC composite
signal, 7.5 IRE units is the lowest point in the signal that luminance
components are permitted. Luminance information falling below this point
is cut off and lost. The "setup level", it is the blackest/darkest part
of the video picture (7.5 IRE). "Superblack" is a term used to refer to
a 0.0 IRE level. Signal Level corresponding to minimum light output, (the
- The part of the video
signal that contains no picture information. A Signal applied to prevent
unwanted signals from being visible. Such signals would be synchronizing
pulses, burst VITC etc.
- Blanking Level
- Blanking level (or
pedestal) is the level of the video signal at 0 IRE before and after the
horizontal sync and during the vertical interval. Blanking refers
to the period of time when the horizontal and vertical retrace take place.
- Blanking Signal
- The pulses added to
the video signal to indicate that the scanning beam should be shut off
for the period of retrace time.
- Chemical for removing
the metallic silver image from developed color emulsions.
- Bleach Bypass/Reduction
- During color film processing when bleaching
is not carried to completion, it is called reducing or bypass. Some of
the silver image remains and less of the color dye is coupled creating
a distinctive contrasty faded look.
- A term that refers to crisp edges that
are not, usually as a result of some overload. Examples include fuzzy titles
in film opticals as a result of over exposure, and chroma bleed on videotape
recordings caused by the saturation being to high in the source material.
- Rectangular area of
picture, usually 8 x 8 pixels in size, which are individually subjected
to DCT coding as part of a digital picture compression process.
Artifact of compression generally showing
momentarily as misplaced rectangular areas of picture with distinct boundaries.
This is one of the major defects of digital compression, its visibility
generally depending on the amount of compression used, the quality of the
original signal, and the quality of the coder. The visible blocks may be
8 x 8 DCT blocks or "misplaced blocks"-16 x 16 pixel macroblocks, due to
the failure of motion prediction/estimation in encoder or other motion
vector system, such as a standards converter.
- Optical Enlargement of an image
- Blue Field
- A test signal.
A proprietary Microsoft Windows image format. This file format cannot be
used on a Web page.
- One of the most popular of the coaxial connectors, the
BNC was developed in the late 1940's toward the end of WWII. The name BNC
stands for Amphenol engineer, Carl Concelman and Bell Labs engineer, Paul
Neill who co-invented the BNC connector: ergo the (B)ayonet (N)eill (C)oncelman
connector. Bayonet describes the interface coupling mechanism, while Neill and
Concelman were the inventors of the N and C connectors.
- The BNC is essentially a miniature version of the C
connector which is a Bayonet version of the N connector. BNC connectors are
available in both 50 and 75 ohm versions, both versions will mate together.
The 50 ohm connector, used primarily for RF, is designs operate up to a
frequency of 4 GHz. The 75 ohm version is usually used for video applications
and cable television. BNC connectors are used in many applications, some of
which are flexible networks, instrumentation and computer peripheral
- The TNC version is a threaded model: the (T)hreaded (N)eill
- Boot Up
- To start up. Most
computers contain a system operating program that they read out of memory
and operate from after power up or restart. The process of reading and
running that program is called boot up.
- Collection of services
marketed as a single entity.
- Bouquet Association
- Provides information
regarding bouquets including the name and a list of services for each bouquet.
- Bits Per Second
The speed, in bits per second, at which binary data passes through a cable
or communication channel.
point where playback can be stopped and resumed again on the next frame
after a period of time. Also a space of time in a program where spots,
promos and/or PSAs can be inserted. As it applies to an automation system:
An event in a playlist that does nothing more than stop transmission of
the list. A break may be used to delimit a pod (group) of compiled material. An
event in a playlist that does nothing more than stop transmission of the list. A
break may be used to delimit a pod (group) of compiled material.
- Break - Break
- Combination of breaks
which can be applied to programs of a particular duration, such as 30 minutes
or 60 minutes, which air on a particular service, during a particular time
period (e.g. every day, Monday-Friday, primetime).
- A momentary image
distortion caused by the loss of sync. Also, intermittent momentary
loss of picture or sound.
- A slow, rhythmic variation in either signal
or scanning amplitude.
- Refers to the portion
of the video signal which lies between the rising edge of the horizontal
sync pulse and the beginning of the color burst signal. The breezeway
is located on the back porch.
- An electronic device
which mixes or switches the signals from three or more locations for audio
or video teleconferencing.
- Bridging Switcher
- A video switcher often
used in CCTV security applications which contains two video outputs. Normally,
one output is dedicated for sequential viewing of the cameras while the
other allows manual call-up of any desired camera.
- Another term for the
luminance signal (Y) that carries information about the amount of light
at each pixel in the image.
- 1. A response that
is the same over a wide range of frequencies. 2. Capable of handling frequencies
greater than those required for high-grade voice communications.