PhaseDifferencePostFilter

Overview

Phase Difference Post Filter

Module Pack

awe-mod-dspc-vui

ClassID

classID = 16504

Type Definition

typedef struct _ModulePhaseDifferencePostFilter
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
FLOAT32 filterDelayThreshold;                 // Threshold to determine if a time-freq bin is within the specified direction
FLOAT32 targetWidth;                          // The width of the target direction, in degrees. Calculated from targetDir, micSpacing, and filterDelayThreshold
FLOAT32 maskAttenDB;                          // dB units - attenuation in the time-freq bin if the sound from that bin is not in the specified direction
FLOAT32 maskAtten;                            // Linear units - attenuation in the time-freq bin if the sound from that bin is not in the specified direction
FLOAT32 timeDomainSR;                         // Sample rate - in time domain
FLOAT32 targetDir;                            // Target direction, in degrees. NOT Implemented
FLOAT32 micSpacing;                           // Mic Spacing, in meters.
INT32 fftSize;                                // FFT Size
INT32 numBins;                                // Number of bins
INT32 numFilters;                             // Number of Gammatone Filters
FLOAT32 epsilon;                              // A small number
FLOAT32* gtFilterMag;                         // Matrix holding the magnitude of gammatone filter coefficients (real)
FLOAT32* phaseDiff;                           // Phase difference, in radians. Part of scratch.
FLOAT32* oneOverExpectedPhaseDiff;            // One over the expected phase difference.
FLOAT32* W;                                   // Gammatone domain weights
FLOAT32* mu;                                  // Mask
FLOAT32* mu_g;                                // Mask after Gammatone filterbank
} ModulePhaseDifferencePostFilterClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range
filterDelayThreshold	float	parameter	0	0.2	0:10
targetWidth	float	derived	0	6.554	Unrestricted
maskAttenDB	float	parameter	0	-40	-60:0
maskAtten	float	derived	0	0.01	Unrestricted
timeDomainSR	float	const	0	16000	Unrestricted
targetDir	float	parameter	0	0	Unrestricted
micSpacing	float	parameter	0	0.075	Unrestricted
fftSize	int	const	0	512	Unrestricted
numBins	int	const	0	257	Unrestricted
numFilters	int	const	0	40	Unrestricted
epsilon	float	const	0	1e-19	Unrestricted
gtFilterMag	float*	derived	0	[256 x 40]	Unrestricted
phaseDiff	float*	derived	1	[257 x 1]	Unrestricted
oneOverExpectedPhaseDiff	float*	derived	1	[257 x 1]	Unrestricted
W	float*	derived	1	[40 x 1]	Unrestricted
mu	float*	derived	1	[257 x 1]	Unrestricted
mu_g	float*	derived	1	[257 x 1]	Unrestricted

Pins

Input Pins


Name	in
Description	input
Data type	float
Channel range	2
Block size range	257
Sample rate range	Unrestricted
Complex support	Complex

Output Pins


Name	out
Description	output
Data Type	float

Scratch Pins


Channel Count	1
Block size	257
Sample rate	48000


Channel Count	1
Block size	257
Sample rate	48000

Matlab Usage

File Name: phase_difference_post_filter_module.m 
 M=phase_difference_post_filter_module(NAME, numFilters, fftSize) 
 Creates a phase difference post filter module 
 Currently, only 2 channels are supported. 

  description TBD 

 Arguments: 
     NAME - name of the module.