LV2 Parameters

ID	http://lv2plug.in/ns/ext/parameters
Version	1.4
Discuss	devel@lists.lv2plug.in (subscribe)

Index
API

This is a vocabulary for parameters that are common in audio processing software. A parameter is purely a metadata concept, unrelated to any particular code mechanism. Parameters are used to assign meaning to controls (for example, using lv2:designation for ports) so they can be used more intelligently or presented to the user more efficiently.

Index

Classes	Instances
ControlGroup CompressorControls EnvelopeControls FilterControls OscillatorControls	amplitude attack bypass cutoffFrequency decay delay dryLevel frequency gain hold pulseWidth ratio release resonance sampleRate sustain threshold waveform wetDryRatio wetLevel

Classes

CompressorControls

Class

Label

Compressor Controls

Subclass of

Typical controls for a compressor.

ControlGroup

Class

Label	Control Group
Subclass of	pg:Group
Superclass of	CompressorControls
	EnvelopeControls
	FilterControls
	OscillatorControls

A group representing a set of associated controls.

EnvelopeControls

Class

Label

Envelope Controls

Subclass of

ControlGroup

pg:element

lv2:designation	delay
lv2:index	0

pg:element

lv2:designation	attack
lv2:index	1

pg:element

lv2:designation	hold
lv2:index	2

pg:element

lv2:designation	decay
lv2:index	3

pg:element

lv2:designation	sustain
lv2:index	4

pg:element

lv2:designation	release
lv2:index	5

Typical controls for a DAHDSR envelope.

FilterControls

Class

Label

Filter Controls

Subclass of

Typical controls for a filter.

OscillatorControls

Class

Label

Oscillator Controls

Subclass of

Typical controls for an oscillator.

Instances

amplitude

Instance

Label	amplitude
Type	lv2:Parameter

An amplitude as a factor, where 0 is silent and 1 is unity.

attack

Instance

Label	attack
Type	lv2:Parameter

The duration of an envelope attack stage.

bypass

Instance

Label	bypass
Type	lv2:Parameter

A boolean parameter that disables processing if true.

cutoffFrequency

Instance

Label	cutoff frequency
Type	lv2:Parameter

The cutoff frequency, typically in Hz, for a filter.

decay

Instance

Label	decay
Type	lv2:Parameter

The duration of an envelope decay stage.

delay

Instance

Label	delay
Type	lv2:Parameter

The duration of an envelope delay stage.

dryLevel

Instance

Label	dry level
Type	lv2:Parameter

The level of the unprocessed component of a signal.

frequency

Instance

Label	frequency
Type	lv2:Parameter

A frequency, typically in Hz.

gain

Instance

Label	gain
Type	lv2:Parameter
units:unit	units:db
lv2:default	0.0
lv2:maximum	20.0
lv2:minimum	-20.0

Gain in decibels.

hold

Instance

Label	hold
Type	lv2:Parameter

The duration of an envelope hold stage.

pulseWidth

Instance

Label	pulse width
Type	lv2:Parameter

The width of a pulse of a rectangular waveform.

ratio

Instance

Label	ratio
Type	lv2:Parameter

Compression ratio.

release

Instance

Label	release
Type	lv2:Parameter

The duration of an envelope release stage.

resonance

Instance

Label	resonance
Type	lv2:Parameter

The resonance of a filter.

sampleRate

Instance

Label	sample rate
Type	lv2:Parameter

A sample rate in Hz.

sustain

Instance

Label	sustain
Type	lv2:Parameter

The level of an envelope sustain stage as a factor.

threshold

Instance

Label	threshold
Type	lv2:Parameter

Compression threshold.

waveform

Instance

Label	waveform
Type	lv2:Parameter

The waveform "fader" for oscillators or modulators that have several.

wetDryRatio

Instance

Label	wet/dry ratio
Type	lv2:Parameter

The ratio between processed and bypassed levels in the output.

The ratio between processed and bypass components in output signal. The dry and wet percentages can be calculated from the following equations:

dry = (wetDryRatio.maximum - wetDryRatio.value) / wetDryRatio.maximum
wet = wetDryRatio.value / wetDryRatio.maximum

Typically, maximum value of 1 or 100 and minimum value of 0 should be used.

wetLevel

Instance

Label	wet level
Type	lv2:Parameter

The level of the processed component of a signal.