ScalerDBControl

Overview

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

Discussion

Scales all input channels by a single gain value. The first pin is the control pin. The gain (in dB) value is provided at the first sample of 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. The module can also handle complex data but in the case of complex data no smoothing is performed and the gain value is applied to both the real and imaginary parts.

Module Pack

Standard

ClassID

classID = 25

Type Definition

typedef struct _ModuleScalerDBControl
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
FLOAT32 smoothingTime;                        // Time constant of the smoothing process
FLOAT32 currentGain;                          // Instantaneous gain applied by the module.  This is also the starting gain of the module.
FLOAT32 smoothingCoeff;                       // Smoothing coefficient
} ModuleScalerDBControlClass;

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	gain (in dB)
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_db_control_module.m 
 M=scaler_db_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.