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Overview

Estimates the direction of arrival in a 2d circle

Type Definition

typedef struct _ModuleGCCDOAV1
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numMics;                                // Number of mics in the array
    INT32 numDirs;                                // Number of look directions
    INT32 maxNumSources;                          // Maximum number of sources to identify
    INT32 interpFactor;                           // Interpolation factor
    INT32 fftSize;                                // Size of FFT upstream from this module
    INT32 numBins;                                // Number of bins. This should be the input block size
    INT32 useInputWeightingPin;                   // Use input weighting pin
    INT32 numPairs;                               // Number of microphone pairs
    INT32 xCorrsZeroSamp;                         // 0th sample index in the xcorr data
    FLOAT32 noiseFloorDBOffset;                   // Offset, in DB, for noise floor weighting. Higher value will weight noise floor less.
    INT32 interpBS;                               // Block Size at interpolated rate
    FLOAT32 interpSR;                             // Sample rate at interpolated rate
    INT32 lookDirLow;                             // Min look direction, in degrees. The low end of the DOA look direction.
    INT32 lookDirHigh;                            // Max look direction, in degrees. The high end of the DOA look direction.
    FLOAT32 epsilon;                              // Small number
    FLOAT32 c;                                    // Speed of sound in meters per sec
    FLOAT32 windowSize;                           // How much to extend the look window when comparing measured delays with theoretical time delays. This is relative number.
    INT32 removalWindowDelta;                     // Number of samples to remove when filtering DOA Peaks
    INT32 tauMaxMax;                              // Maximum theoretical time delays for all mic pair
    INT32 tauMinMin;                              // Minimum theoretical time delays for all mic pair
    INT32 tdZeroSamp;                             // windowed xcorr 0 delay sample index
    INT32 tdLength;                               // Length of the xcorr vector, after windowing
    FLOAT32* micArrayCoords;                      // Microphone geometry in cartesian coordinates and in meters. The vector going from (0,0) to (1,0) is considered 0 degrees.
    FLOAT32* noiseFloorVar;                       // Microphone noise floor measurement, in linear units.
    INT32* taus;                                  // Theoretical time delays based on the mic geometry and other factors.
    FLOAT32* lookDirs;                            // Look directions, in degrees.
    INT32* tauMax;                                // Maximum theoretical time delays for each mic pair
    INT32* tauMin;                                // Minimum theoretical time delays for each mic pair
    FLOAT32* G;                                   // Temporary variable from the processing function
    FLOAT32* doaValues;                           // Temporary variable from the processing function
    FLOAT32* td;                                  // Temporary variable from the processing function
    FLOAT32* tdTmp;                               // Temporary variable from the processing function
    void * ifft_struct_pointer;                   // Points to an instance of an IFFT module
} ModuleGCCDOAV1Class;

Variables

Properties

Name

Type

Usage

isHidden

Default value

Range

Units

numMics

int

const

0

6

Unrestricted

numDirs

int

const

0

360

Unrestricted

maxNumSources

int

const

0

3

Unrestricted

interpFactor

int

const

0

16

Unrestricted

fftSize

int

const

0

512

Unrestricted

numBins

int

const

0

257

Unrestricted

useInputWeightingPin

int

const

0

1

Unrestricted

numPairs

int

const

0

15

Unrestricted

xCorrsZeroSamp

int

const

0

128

Unrestricted

noiseFloorDBOffset

float

parameter

0

5

-20:20

interpBS

int

derived

0

4097

Unrestricted

interpSR

float

derived

0

196608000

Unrestricted

lookDirLow

int

parameter

0

0

0:360

lookDirHigh

int

parameter

0

360

0:360

epsilon

float

parameter

1

1e-16

Unrestricted

c

float

parameter

1

343

Unrestricted

windowSize

float

parameter

1

0

Unrestricted

removalWindowDelta

int

parameter

1

2

Unrestricted

tauMaxMax

int

derived

1

0

Unrestricted

tauMinMin

int

derived

1

0

Unrestricted

tdZeroSamp

int

derived

1

0

Unrestricted

tdLength

int

derived

1

1

Unrestricted

micArrayCoords

float*

parameter

0

[6 x 2]

Unrestricted

noiseFloorVar

float*

parameter

0

[257 x 1]

0:1

taus

int*

derived

1

[15 x 360]

Unrestricted

lookDirs

float*

derived

1

[1 x 360]

Unrestricted

tauMax

int*

derived

1

[15 x 1]

Unrestricted

tauMin

int*

derived

1

[15 x 1]

Unrestricted

G

float*

state

0

[4097 x 1]

Unrestricted

doaValues

float*

state

0

[360 x 1]

Unrestricted

td

float*

state

0

[1 x 15]

Unrestricted

tdTmp

float*

state

0

[8192 x 1]

Unrestricted

ifft_struct_pointer

void *

state

1

Unrestricted

Pins

Input Pins

Name: micIn

Description: Microphone array input - in frequency domain

Data type: float

Channel range: 6

Block size range: 257

Sample rate range: Unrestricted

Complex support: Complex

Name: weight

Description: Weighting of each microphone

Data type: float

Channel range: 6

Block size range: 257

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: estDirs

Description: Estimated directions, in degrees

Data type: float

Name: estEnergy

Description: Estimated relative energy for each estimated direction

Data type: float

Scratch Pins

Channel count: 1

Block size: 4097

Sample rate: 48000

Channel count: 1

Block size: 8192

Sample rate: 48000

Channel count: 1

Block size: 8192

Sample rate: 48000

MATLAB Usage

File Name: gcc_doa_v1_module.m

 M = gcc_doa_v1_module(NAME, numMics, numDirs, maxNumSources,  interpFactor, fftSize, useInputWeightingPin)
 Given the DOA output, this module finds the direction of the interference sound. 
 Arguments:
    NAME - name of the module.
    numMics - number of microphones in the microphone array
    numDirs - number of look directions to sample
    maxNumSources - maximum number of sources to find
    interpFactor - how much to interpolate for better estimation at the
    cost of more MIPS
    fftSize - Size of the FFT operation done upstream from this module.
    The input blocksize is expected to be fftSize/2 + 1. 
    useInputWeightingPin - If true, then a 2nd input pin will be used for
    the weighting. The input pin is expected to have numMics channels and
    same block size as the other input.
 The input pin is expected to be the microphone signals after processed with the WOLA Analysis filter bank.
 
 The first output pin contains maxNumSources channel of size 1. This is the
 estimated direction of arrival. This is in degrees, between 0 and 359.
 Direction 0 corresponds to 
 The second output pin contains maxNumSources channel of size 1. This is the
 associated energy of the direction of arrival estimate (the first
 output).
 
 Copyright 2018.  DSP Concepts, Inc.  All Rights Reserved.

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