Grass Valley Dictionary

Dictionary of Technical Terms - B

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B3ZS (bipolar with three zero substitution)

In telecommunications, a DS3 coding method in which strings of three data 0's are replaced with either a B0V or 00V. B is a bipolar pulse, and V is a pulse of the same polarity as the previous pulse. B0V or 00V is output so that the number of B pulses between consecutive V pulses is odd.

B6ZS (bipolar with six zero substitution)

In telecommunications, a DS2 coding method in which strings of six data 0's are replaced with 0VB0VB. B is a bipolar pulse, and V is a pulse of the same polarity as the previous pulse.

B8ZS (Eight zero substitution)

In telecommunications, a DS1 coding method in which strings of eight data zeros are replaced with the following: 000VB0VB. B is a bipolar pulse, and V is a pulse of the same polarity as the previous pulse.

background (program video)

In video keying operations, the main "program" picture into which keyed video is inserted. Usually the image with the lowest priority in an effect; i.e., the bottom layer.

background color cancellation (BCC)

A chroma key feature which senses the color of the chroma key backing and replaces it in the chroma key scene with a complementary color. As a result, the two colors cancel each other. This helps to eliminate the undesirable halo or fringing effect surrounding the foreground object in the chroma key.

background color suppression (BCS)

A chroma key feature which senses the color of the chroma key backing and replaces it with an adjustable luminance level. This helps prevent any of the backing color from showing in the chroma key.

background generator

A video generator that produces a solid-color output which can be adjusted for hue, chroma, and luminance.

A dissolve between two background (program) video pictures in which one gradually replaces the other.

background transition

A transition between signals selected on the preset background and program background buses of a switcher.

background video

1. Video that forms a background scene into which a key may be inserted. 2. A solid-color video output generated by the background generator within a device, such as a production switcher, for use as background video in key effects.

background wash

A color matte effect in which the matte color graduates from dark to light or from one color to another.

background wipe

A transition in which a background (program) video picture is added, removed, or replaced with another video picture as a geometric pattern moves across the screen.

backplane (rear connector channel, mother- board)

The physical area, usually at the rear of an electronics frame, where modules and cables plug into the system.

The portion of a video signal that occurs during blanking from the end of horizontal sync to the beginning of active video. The blanking signal portion which lies between the trailing edge of a horizontal sync pulse and the trailing edge of the corresponding blanking pulse. Color burst is located on the back porch.

The process of rewinding a videotape from the desired edit-in point, to facilitate proper speed and synchronization.

Method of calculating the edit-in point by subtracting the duration of the edit from the edit-out point.

A redundant power supply that takes over if the primary power supply fails.

A circuit having two sides (conductors) carrying voltages which are symmetrical around a common reference point, typically ground.

Describes the dynamic characteristics of a meter movement-most notably, response time, damping, and overshoot. Also used to describe the physical characteristics of tape machines (inertial, ringing, damping, etc.).

bandpass filter

A filter with a single transmission band that attenuates the frequencies on either side of the band.

The complete range of frequencies over which a circuit or electronic system can function with minimal signal loss, typically less than 3 dB. The information carrying capability of a particular television channel. In PAL systems the bandwidth limits the maximum visible frequency to 5.5 MHz, in NTSC, 4.2 MHz. The CCIR 601 luminance channel sampling frequency of 13.5 MHz was chosen to permit faithful digital representation of the PAL and NTSC luminance bandwidths without aliasing.

1. A group of E-MEM Effects Memory registers, typically ten registers. 2. A mix/effects level in a video switcher, i.e., M/E bank.

See color bars.

The frequency band occupied by a signal that modulates a carrier before it combines with the carrier in the modulation process.

A form of low-frequency distortion resulting in a shift in the DC level of the signal.

A unit of signaling speed equal to the number of signal events per second. Baud is equivalent to bits per second in cases where each signal event represents exactly one bit. Often the term baud rate is used informally to mean baud, referring to the specified maximum rate of data transmission along an interconnection. Typically, the baud settings of two devices must match if the devices are to communicate with one another.

Background color cancellation.

Binary coded decimal. A coding system in which each decimal digit from 0 to 9 is represented by four binary (0 or 1) digits.

Background color suppression.

Video distortion that appears as short black lines extending to the right of bright objects within a scene.

A device that makes a clicking or chirping sound to alert the user that a control knob has reached a limit.

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.

A cable manufacturer.

A group of digital picture manipulator special effects in which the video image is twisted about an axis.

Bit error rate.

Informal name for Betacam, a professional color difference videotape recording format that uses the Y, R-Y, and B-Y color difference components. Also the name of a consumer videotape recording format that is completely different from the professional Betacam format. Betacam

Portable camera/recorder system using 1/2-inch tape originally developed by Sony. The name may also refer just to the recorder or the interconnect format; Betacam uses a version of the Y, R-Y, B-Y color difference signal set. Betacam is a registered trademark of the Sony Corporation.

A superior performance version of Betacam. SP uses metal particle tape and a wider bandwidth recording system.

1. In digital picture manipulators, a characteristic of location/positioning which controls the direction of the motion path as it passes through a key frame position. 2. Current or voltage applied to a circuit to set a reference operating level for proper circuit performance, such as the high frequency bias current applied to an audio recording head to improve linear performance and thus reduce distortion.

A base-2 numbering system using the two digits 0 and 1 (as opposed to ten 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 another corresponding to 1. All computer programs are executed in binary form.

A signal that contains both positive-going and negative-going amplitude. May also contain a zero amplitude state.

bipolar violation (BPV)

In telecommunications, a data 1 pulse that is the same polarity as the last data 1 pulse. Indicates a data error or zero substitution.

Broadband Integrated Services Digital Network.

Binary digit. The smallest unit of data in a digital system. A bit is a single one or zero. 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.

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 SMPTE125M, EBU 3267-E and ITU-R BT.656 (CCIR 656).

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).

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.

A continuous series of bits transmitted on a line.

See color black and stripe.

See color black.

The lowest transmittable luminance level that can occur during the active picture portion of a video signal. When viewed on a monitor this signal level portrays the color black.

black reference

See black level.

blanking insertion

See blanking processor.

The voltage level equal to or below the black level that acts as a signal to turn off the scanning beam of a camera or monitor.

blanking processor

A circuit which strips blanking, sync, and sometimes burst from a signal and replaces them with clean blanking, sync, and burst from a reference source. This process ensures that blanking, sync, and burst do not contain any unwanted noise, level changes, or timing shifts.

The specific length of time during which blanking takes place.

blanking (BLKG)

1. The time period when picture information is shut off. Blanking is a voltage level which is at or below black picture level and acts as a signal to turn off the scanning beam. Synchronizing pulses which control invisible retrace of scanning are active during the blanking period. 2. A standard signal from a sync generator used to create blanking in video.

Occurs in a multistage routing system when a destination requests a source and finds that source unavailable. In a tie line system, this means that a destination requests a tie line and receives a "tie line busy" message, indicating that all tie lines are in use.

1. The defocusing of regions of the picture where brightness is excessive. 2. On video monitors, adjusting the white levels so that they are just at the point of leaving grey and becoming white.

One of the three primary color signals (red, green, and blue) produced by a camera or applied to a monitor.

In telecommunications, an alarm signal composed of 1's and 0's (101010, etc.) substituted for lost valid input signal to indicate loss of the signal to downstream equipment.

B-mode assembly

A GVG editor term. See checkerboard assembly.

Bayonet Neill-Concelman. A cable connector used extensively in television and named for its inventor.

1. A printed circuit consisting of a flat board of insulating material with conductive circuits etched on its surface. 2. In GVG terminology, a board (as opposed to a module) is a printed circuit before it has been stuffed with electrical components. The term board is also used for fully-stuffed printed circuit boards that bolt into place in an assembly, whereas the term module refers to printed circuit assemblies that slide into position in a cell.

Bell Operating Company.

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.

An effect where a color or monochrome edge is produced around a key or a wipe pattern.

A key enhancement option that produces a black, white, or colored border or drop shadow around the key or changes the key into a matte-filled outline.

1. Overshoot of the proper DC level of the video signal due to multiple AC couplings in a signal path. Causes sudden brightness in the picture.

Characteristic of circuit or equipment where overshoot of blanking DC levels does not occur.

A rectangular key mask which is adjustable for width and height. See also mask.

boundary replicate

A digital picture manipulation effect which reverses the soft, dark key edges caused by the defocus effect.

A take operation in which the audio and video signals do not automatically follow one another; audio and video are switched in separate operations.

Disturbance in the video or audio signal, often caused by loss of sync or videotape damage.

In an analog video signal, that portion of the "back porch" between the trailing edge of the sync pulse and the start of the color burst.

1. A circuit that matches other circuits to each other. 2. To place one circuit in parallel with another.

In NTSC and PAL video signals, the brightness information at any particular instant in a picture is conveyed by the corresponding instantaneous DC level of active video. Brightness control is an adjustment of setup (also called black level or black reference).

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 (higher than 3 to 4 kilohertz).

Bruch blanking sequence

A PAL blanking sequence named after its inventor. The sequence ensures that each field starts with the same burst phase as the burst at the end of the previous field.

Basic Serving Arrangement.

Basic Service Element.

1. A circuit or component which isolates one electrical circuit from another. 2. A digital storage device used to compensate for a difference in the rate of flow of information or the time of occurrence of events when transmitting information from one device to another. 3. In telecommunications, a protective material used in cabling optical fiber to cover and protect the fiber. The buffer material has no optical function.

A post production term relating to a group of effects used for video program lead-ins.

burst (color burst)

Seven to nine cycles (NTSC) or ten cycles (PAL) of subcarrier, placed near the end of horizontal blanking to serve as the phase (color) reference for the modulated color subcarrier. Burst serves as the reference for establishing the picture color.

burst flag (BF)

A pulse used to gate the color reference subcarrier (burst) onto the back porch of each horizontal blanking interval. Also called burst gate (BG).

burst gate (BG)

See burst flag.

burst of subcarrier

See burst or color burst

In composite video signals, the amplitude and angle of the color reference signal.

A group of conductors that together constitute a major signal path. A signal path to which a number of inputs may be connected to feed to one or more outputs.

A code number sent out to activate a particular device on a shared communications bus.

button per source

A control panel which has a separate button for each source. Also called button per function.

BVB (black-video-black)

An editing mode in which an edit is previewed starting with a black picture, followed by a preview of the edit, and ending in black.

One of the color signals (blue minus luminance) of a color difference video signal set. The formula for deriving B-Y from the red, green, and blue component video signals is -.30R -.59G -.89B. See Y, R-Y, B-Y.

A relay used to bypass the normal electrical route in the event of power, signal, or equipment failure.

bypass switcher

An audio-follow-video switcher usually associated with a master control switcher. Used to bypass the master control switcher output during emergencies, failures, or off-line maintenance.

A group of data bits which are processed together. Typically, a byte consists of 8, 16, or 32 bits.

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Last Modified: 01:44pm PDT, September 11, 1995