SMixer2x1

Overview

2-input x 1-output smoothly varying mixer module

Discussion

Mixes 2 inputs into a single output. The mixing gain parameters are exponentially smoothed (first order IIR) at the sample rate, with the smoothingTime parameter determining the smoothing rate for both of the gain values. The variables, gain1 and gain2, specify the target gains for the mixing process. The variables, currentGain1 and currentGain2, specify the instantaneous gains applied, and these exponentially approach the target gains. At build time, currentGain1 is set to gain1 and currentGain2 is set to gain2. This causes the mixers to startup in a converged state.

Type Definition

CODE

typedef struct _ModuleSMixer2x1
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 gain1;                                // Desired gain applied to first input channel.
    FLOAT32 gain2;                                // Desired gain applied to second input channel.
    FLOAT32 smoothingTime;                        // Time constant of the smoothing process.
    FLOAT32 currentGain1;                         // Instantaneous gain for the first input channel.
    FLOAT32 currentGain2;                         // Instantaneous gain for the second input channel.
    FLOAT32 smoothingCoeff;                       // Smoothing coefficient.
} ModuleSMixer2x1Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
gain1	float	parameter	0	1	-10:10
gain2	float	parameter	0	1	-10:10
smoothingTime	float	parameter	0	10	0:1000	msec
currentGain1	float	state	1	1	-10:10	linear
currentGain2	float	state	1	1	-10:10	linear
smoothingCoeff	float	derived	1	0.002081	Unrestricted

Pins

Input Pins

Name: in1

Description: audio input

Data type: {float, int, fract32}

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Name: in2

Description: audio input

Data type: {float, int, fract32}

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: {float, int, fract32}

MATLAB Usage

File Name: smixer2x1_module.m

CODE

 M=smixer2x1_module(NAME)
 Creates a 2-input 1-output smoothly varying mixer for use in the Audio
 Weaver environment.  
 Arguments:
    NAME - name of the module.
 The module automatically determines the dataType based on the dataType of
 the input pin. You can explicitly set the data type using an optional
 second argument:
 M=smixer2x1_module(NAME, DATATYPE)
 where DATATYPE is: 'float' or 'fract32'. Explicitly setting the DATATYPE
 is only required for code generation.