## extends OcaActuator

Dynamic compression / expansion curve. Curve means a function that expresses the relationship of output level to input level. The dependent variable (Y) of the curve is output level; the independent variable (X) is input level. Every curve is composed of (n+1) straight-line segments joined by (n) small fillets called knees. Each knee occurs at a particular input level value called the threshold. Each segment is characterized by its slope. | / | S3 / | S2 / | T1-------------T2 | / | S1 / | / | / +------------------------------------ This "drawing" shows a three-segment curve. The horizontal axis is input level, vertical axis is output level. Algebraically, a curve is a function Out = Curve( In, T[1..n-1], S[1..n], K[1..n-1] ) where n is the number of segments, and In is input level in dBr Out is output level in dBr T[1...n-1] is an array of thresholds in dBr S[1...n] is an array of slopes in dBr per dBr, i.e. unitless K[1..n] is the knee parameter, an implementation-dependant parameter that specifies the shape of the curve around the knee. Each segment has a slope that expresses its ratio of output level to input level. Note that this slope is the inverse of what dynamics processors call "ratio". For example, a ratio of 2:1 is represented by a curve segment with slope 1/2 = 0.5. This model can represent familiar audio dynamics elements (we ignore K[] in these examples): - Compressor with ratio of 2:1 and threshold of 10dBr: n = 2 T[1] = 10 S[1] = 1 S[2] = 0.5 - Hard limiter with threshold of 18dBr: n = 2 T[1] = 18 S[1] = 1 S[2] = 0 - Upward expander with ratio of 1.5:1 and threshold of -12dBr: n = 2 T[1] = -12 S[1] = 1 S[2] = 1.5 - Downward expander (gate) with ratio of 50:1 and threshold of -45dBr: n = 2 T[1] = -45 S[1] = 50 S[2] = 1 This class, OcaDynamicsCurve, adds two additional parameters to the basic curve mechanism. Out = Curve( In, T[1..n-1], S[1..n], K[1..n-1] , Floor, Ceiling) where In, T[], and S[], and K[] are as defined above. Floor is the lowest gain (in dBr) that the dynamics element is allowed to produce. Ceiling is the highest gain (in dBr) that the dynamics element is allowed to produce. To show the use of Floor and Ceiling, we revisit some of the examples above (again, K[] is ignored): - Compressor with ratio of 2:1, threshold of 10dBr, and max gain reduction of 20dB: n = 2 T[1] = 10 S[1] = 1 S[2] = 0.5 Floor = -20 Ceiling = 0 - Upward expander with ratio of 1.5:1, threshold of -12dBr, and max gain boost of 4dB: n = 2 T[1] = -12 S[1] = 1 S[2] = 1.5 Floor = 0 Ceiling = 4.0 More complex dynamics curves can be modeled by using more segments (n > 2).

## Properties

#### Level: 1 Index: 1

Number that uniquely identifies the class. Note that this differs from the object number, which identifies the instantiated object. This property is an override of the OcaRoot property.

#### Level: 1 Index: 2

Identifies the interface version of the class. Any change to the class definition leads to a higher class version. This property is an override of the OcaRoot property.

### OcaUint8nSegments

#### Level: 4 Index: 1

Number of curve segments.

#### Level: 4 Index: 2

T[1..n-1]. See class description for details.

### OcaList<OcaFloat32> Slope

#### Level: 4 Index: 3

S[1..n]. See class description for details.

### OcaList<OcaFloat32> KneeParameter

#### Level: 4 Index: 4

K[1..n]. See class description for details.

#### Level: 4 Index: 5

Lowest allowed dynamic gain value. See class description for details.

#### Level: 4 Index: 6

Highest allowed dynamic gain value. See class description for details.

## Methods

### OcaDynamicsCurve::GetNSegments ( ) → ( OcaUint8n, OcaUint8minN, OcaUint8maxN)

#### Level: 4 Index: 1

Gets the number of curve segments. The return value indicates whether the value was successfully retrieved.

#### Level: 4 Index: 2

Sets the number of curve segments. The return value indicates whether the data was successfully set. If this method increases the value of n, the data in properties Threshold, Slope, and KneeParameter of the new segment are by default set to the values of the previous segment.

#### Level: 4 Index: 3

Gets the list of Threshold values. The return value indicates whether the data was successfully retrieved.

#### Level: 4 Index: 4

Sets the list of Threshold values. The return value indicates whether the values were successfully set.

### OcaDynamicsCurve::GetSlope ( ) → ( OcaList<OcaFloat32> slope, OcaList<OcaFloat32> minSlope, OcaList<OcaFloat32> maxSlope)

#### Level: 4 Index: 5

Gets the list of Slope values. The return value indicates whether the list was successfully retrieved.

### OcaDynamicsCurve::SetSlope ( OcaList<OcaFloat32> slope )

#### Level: 4 Index: 6

Sets the list of Slope values. The return value indicates whether the values were successfully set.

### OcaDynamicsCurve::GetKneeParameter ( ) → ( OcaList<OcaFloat32> parameter, OcaList<OcaFloat32> minParameter, OcaList<OcaFloat32> maxParameter)

#### Level: 4 Index: 7

Gets the list of KneeParameter valuess. The return value indicates whether the list was successfully retrieved.

### OcaDynamicsCurve::SetKneeParameter ( OcaList<OcaFloat32> parameter )

#### Level: 4 Index: 8

Sets the list of KneeParameter values. The return value indicates whether the values were successfully set.

#### Level: 4 Index: 9

Gets the value of the DynamicGainCeiling property. The return value indicates whether the data was successfully retrieved.

#### Level: 4 Index: 10

Sets the value of the DynamicGainCeiling property. The return value indicates whether the data was successfully set.

#### Level: 4 Index: 11

Gets the value of the DynamicGainFloor property. The return value indicates whether the data was successfully retrieved.

#### Level: 4 Index: 12

Sets the value of the DynamicGainFloor property. The return value indicates whether the data was successfully set.

#### Level: 4 Index: 13

Sets some or all dynamics curve parameters. The return value indicates if the parameters were successfully set. The action of this method is atomic - if any of the value changes fails, none of the changes are made.