Overview

Smoothly varying linear Fract32 scaler with independent gains in dB units

Discussion

Multichannel scaler, where each input channel has its own individual smoothly varying gain value. The gain parameter consists of an array of gains, one per input/output channel with units of dB. All gain parameters are exponentially smoothed (first order IIR) at the sample rate, with the smoothingTime parameter determining the smoothing rate for all of the gain values.

Type Definition

typedef struct _ModuleScalerNDBSmoothedFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 smoothingTime;                        // Time constant of the smoothing process
    fract32 smoothingCoeff;                       // Smoothing coefficient
    INT32 postShift;                              // Number of bits to shift after the fractional multiply. This is based on gain.range.
    FLOAT32 twoPowMinusPostShift;                 // 2^(-postShift). Used by to streamline the operation of the set function
    FLOAT32* gainDB;                              // Array of gains, one per channel
    fract32* targetGain;                          // Array of gains, one per channel
    fract32* currentGain;                         // Array of instantaneous gains, one per channel
} ModuleScalerNDBSmoothedFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
smoothingTime	float	parameter	0	10	0:1000	msec
smoothingCoeff	fract32	derived	1	0.002081	Unrestricted
postShift	int	derived	1	4	Unrestricted
twoPowMinusPostShift	float	derived	1	0.0625	Unrestricted
gainDB	float*	parameter	0	[1 x 1]	-40:0.1:20	dB
targetGain	fract32*	derived	0	[1 x 1]	Unrestricted
currentGain	fract32*	state	0	[1 x 1]	Unrestricted

Pins

Input Pins

Name: in

Description: Input signal

Data type: fract32

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Output signal

Data type: fract32

MATLAB Usage

File Name: scalern_db_smoothed_fract32_module.m

 M=scalern_db_smoothed_fract32_module(NAME)
 Multichannel scaler module with individual control of gains in each
 channel.  The gain controls are in dB units.  Arguments:
    NAME - name of the module.