Overview

Smooth scaler in which the gain (in linear units) is taken from an input pin

Discussion

The Scaler Control module smoothly scales multichannel input data by a single gain value. The first pin is the control pin. The gain (in linear units) value is provided at the first sample of the first pin. So the module has N+1 number of input pins and N number of output pins Internally, currentGain represents the instantaneous smoothed gain that is applied. currentGain exponentially approaches gain with a time constant equal to smoothingTime.

Type Definition

typedef struct _ModuleScalerControl
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 smoothingTime;                        // Time constant of the smoothing process
    FLOAT32 currentGain;                          // Instantaneous gain applied by the module.
    FLOAT32 smoothingCoeff;                       // Smoothing coefficient
} ModuleScalerControlClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
smoothingTime	float	parameter	0	10	0:1000	msec
currentGain	float	state	1	0	Unrestricted
smoothingCoeff	float	derived	1	0.002081	Unrestricted

Pins

Input Pins

Name: g

Description: linear gain to apply

Data type: float

Channel range: 1

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Name: in1

Description: audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real and Complex

Output Pins

Name: out1

Description: audio output

Data type: float

MATLAB Usage

File Name: scaler_control_module.m

 M=scaler_control_module(NAME,NUMPINS)
 Creates a smoothly varying scaler module which has variable number of 
 input and output pins and each pin can be multichannel and will 
 have the same gain applied to it. The first sample of first pin is used
 as a target gain for the block. The first pin is the control pin.
 The module can also be used to scale complex data. However, the smoothing
 coefficient is ignored and no smoothing is performed in this case.
   Arguments:
    NAME - name of the module.
    NUMPINS - number of audio input/output pins.  By default, NUMPINS=1.