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Glossary

Absolute Value

An absolute value function inverts all values below zero and forces the output to be positive.

Chroma Key Generator

processes the chroma components (PbPr) of a component video signal, allowing key extraction based on Hue and Saturation of the video source

Clipping Amplifier

Also known as a soft key generator or wide range contrast processor. The output is created by amplifying the video source to create a high contrast mask with variable edge width.

Comparator

Also known as a hard key generator or 1-bit ADC (Analog-to-Digital converter) function. When the positive input voltage is greater than the negative input voltage, the output is 1 volt (White Level). Otherwise, the output is 0 volts (Black Level).

Component Key Generator

acts on one color channel at a time, but still includes the entire colorspace in its output function

Doubler

Also known as a saw-to-triangle waveshaper, the doubler is a combination of an absolute value function and clipping amplifier function.

Encoder

A video encoder takes 1 volt scale unipolar signals for Red, Green & Blue color channels, and performs all operations required to convert them into a video signal for display or recording.

Exponential Amplifier

An exponential amplifier changes a linear input voltage into an output with exponential scale.

Fader

a module which performs a transition between two video sources. typically it has a direct key input, without much local control over the key itself.

Frame Synchronizer

A frame synchronizer takes an external video feed and synchronizes it with the system's internal timing. A frame synchronizer is usually required to input multiple external video sources into your system like cameras and media players.

Hard Key

a boolean logic signal which switches between two signals.

Hard Key Generator

typically implemented as a differential analog comparator.

Key

any video signal used to control a transition between two or more other video signals

Key Generator

a module designed to condition an input for the purpose of keying operations

Keyer

a module which has both a key generator and a fader or switcher

Linear Colorizer

combines multiple faders with a multi level key generator function to produce a transition across more than two inputs

Logarithmic Amplifier

An logarithmic amplifier changes a linear input voltage into an output with logarithmic scale.

Luma Key Generator

processes the luma component (Y) of a component video signal, allowing key extraction based on the overall brightness of the video source

Maximum Value

A maximum value function compares two or more inputs, and passes the input with the most voltage to the output.

Minimum Value

A minimum value function compares two or more inputs, and passes the input with the least voltage to the output.

Multi Level Key Generator

produces multiple key signals from a single source, and are often used as the frontend for colorizers and sequencers

Negative

Also known as a voltage mirror. The output is equal to the input voltage is subtracted from 1 volt (White Level).

Ramp Generator

A ramp generator is a waveform generator which produces analog waveforms synchronous to the horizontal or vertical dimensions of the video screen. It is a common component of analog graphics modules, such as shape and pattern generators.

Soft Key

an analog voltage representing the mix ratio between two video signals

Soft Key Generator

typically implemented as a high gain differential amplifier with black and white level clipping

Summing Amplifier

Also known as a Mixer. A summing amplifier adds two or more voltages to each other. The voltages may be unipolar or bipolar scale.

Voltage Controlled Oscillator (VCO)

A voltage controlled oscillator is similar to a ramp generator, only its frequency may be changed or modulated. A voltage controlled oscillator may be free running, or reset in time with the video sync to synthesize a stable pattern.

Window Key Generator

has dual threshold controls, either Upper/Lower or Span/Center