MixerSmoothed

Discussion

THIS MODULE IS DEPRECATED AND NOT RECOMMENDED FOR NEW DESIGNS. PLEASE USE THE MixerV3 MODULE INSTEAD.

This module implements a full M-input x N-output mixer with a total of MxN coefficients. When using the module in MATLAB, the coefficients are contained in the .coeffs matrix with the gain from the ith input to the jth output found at coeffs(i, j). From the C code point of view, the .coeffs array is a one dimensional array of length MxN. The gain from input m (0 <= m <= M-1) to output n (0 <= n <= N-1) is stored at:

coeffs[m + n*M]

Put another way, the first M coefficients are the gains needed to compute the first output channel. The next M coefficients are the gains needed to compute the second output channel, and so out.

The mixer implements smoothing on a sample-by-sample basis. Standard 1st order exponential smoothing is used. Gain adjustments are made to the coeffs matrix. Internally, the module holds a second matrix of instantaneous gains, currentCoeff, which smoothly approaches coeffs. The rate of the smoothing operation is controlled by smoothingTime.

When the module is bypassed, it copies the ith input channel to the ith output channel. If the module has more output channels than input channels, the remaining output channels are set to 0.

Module Pack

Deprecated

ClassID

classID = 2023

Type Definition

typedef struct _ModuleMixerSmoothed
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
FLOAT32 smoothingTime;                        // Time constant of the smoothing process, in msec.
FLOAT32 smoothingCoeff;                       // Smoothing coefficient.
FLOAT32* gain;                                // Linear gain.
FLOAT32* currentGain;                         // Instanteous gain being applied.  This is an internal variable used in the smoothing process
} ModuleMixerSmoothedClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
smoothingTime	float	parameter	0	10	0:500	msec
smoothingCoeff	float	derived	1	0.002081	Unrestricted
gain	float*	parameter	0	[1 x 2]	-60:20
currentGain	float*	state	1	[1 x 2]	Unrestricted

Pins

Input Pins


Name	in
Description	audio input
Data type	float
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	audio output
Data Type	float

Matlab Usage

File Name: mixer_smoothed_module.m 
 M=mixer_smoothed_module(NAME, NUMOUT) 
 Creates a smoothly varying multichannel mixer module for use in  
 the Audio Weaver environment. The mixer has one input and  
 one output pin. Each of the pins can contain multiple interleaved  
 channels. The number of input channels is determined by the upstream 
 audio module. You must specify the number of output channels.   

 Arguments: 
   NAME - name of the module. 
   NUMOUT - number of output channels.