MixerSmoothedFract32

Overview

M-input x N-output smoothly varying mixer

Discussion

This module implements a fixed point version of full M-input x N-output mixer with a total of MxN coefficients. The coefficients are contained in the coeffs matrix with the gain from the ith input to the jth output is found at coeffs(i, j). This 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

Standard

ClassID

classID = 159

Type Definition

typedef struct _ModuleMixerSmoothedFract32
{
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
FLOAT32* gain;                                // Linear gain
fract32* targetGain;                          // Linear gain
fract32* currentGain;                         // Linear gain
} ModuleMixerSmoothedFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
smoothingTime	float	parameter	0	10	0:500	msec
smoothingCoeff	fract32	derived	1	0.0020811	Unrestricted
postShift	int	derived	1	6	Unrestricted
gain	float*	parameter	0	[1 x 2]	-60:20
targetGain	fract32*	derived	1	[1 x 2]	Unrestricted
currentGain	fract32*	state	1	[1 x 2]	Unrestricted

Pins

Input Pins


Name	in
Description	audio input
Data type	fract32
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	audio output
Data Type	fract32

Matlab Usage

File Name: mixer_smoothed_fract32_module.m 
 M=mixer_smoothed_fract32_module(NAME, NUMOUT) 
 Creates a smoothly varying multichannel mixer module for use in  
 the PC 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.