(8.D.2.5) SbDOAV2

Overview

Compute angular 2D direction of arrival of audio sources arriving at the mic array

Discussion

This module computes angular 2D direction of arrival of audio sources arriving at the mic array

Input Pins:

Input Pin 1: Multichannel frequency domain data. Usually output of a WOLA Analysis Module
Number of channels must match the number of microphones in the micGeometry argument

Input Pin 2: Bit map to include/exclude any desired input bins from processing. This will usually be set to all ones
Block size must be equal to the block size, (number of complex values), of Pin 1

Output Pins:

Output Pin 1: Estimated angular direction of arrival for this WOLA block in degrees. This will be an integer between 0 and 360.

Output Pin 2: Confidence value for this angle estimate. This will be an integer. Larger values mean more confidence.

Output Pin 3: Array of 360 floats denoting a histogram of possible angles of arrival for this block. Output pin 1 will be the peak of this histogram.

Module Arguments:

micGeometry: Drop down menu to select mic geometry being used

fftSize: FFTSize used by WOLA Analysis block preceding the SbDOAV2 module

Fs: Sampling rate of time domain data entering WOLA Analysis block

    MicGeomSize:    Dimension in meters of selected mic geometry. This has a different meaning for each mic geometry.
        4_Mic_Square geometry MicGeomSize specifies side length of square.
        4_Mic_Linear geometry MicGeomSize specifies distance between mics.
        4_Mic_Trillium geometry MicGeomSize specifies radius of circle in which triangle is inscribed.
        4_Mics_of_6_7_Mic_Circle geometry MicGeomSize specifies radius of circle in which 4 mics are inscribed.
        Equilateral_Triangle geometry MicGeomSize specifies side length of triangle.
        2_Mic geometry MicGeomSize specifies distance between mics.
        7_Mic_Circle geometry MicGeomSize specifies radius of circle.
        6_Mic_Circle geometry MicGeomSize specifies radius of circle.
        Rectangular geometry MicGeomSize specifies side length of shorter side of 2x1 rectangle.

LowerBin: Frequency bin index of lowest WOLA bin entering SbDOAV2 input pin

    MultiSource: Allows reporting of multiple audio sources, and controls optimization level.
        MultiSource = 1 Report up to 5 audio sources per WOLA block. Angles are reported in the range 0-360 degrees.
        This setting is not optimized and has huge MIPS spikes. This is only suitable for native mode, not any embedded targets.
        MultiSource = 1 overrides any settings for OutputAngles and angles reported will always be in the range 0-360.
        MultiSource = 0 Report only 1 audio source. This setting is optimized for low MIPS and is suitable for embedded and
        native targets. The range of angles reported is controlled by the value of OuputAngles.

    OutputAngles: Select range of angles reported 0-360 or 180-360
        OutputAngles = 0 Report angles in the range 0-360
        OutputAngles = 1 Report angles in the range 180-360. This setting uses slightly less MIPS since we are
        reporting a smaller range of angles. This setting is intended for applications where only an angle range of 180
        is needed, (e.g. a conference room soundbar mounted against a wall)

Inspector Tuning Variables:

    BlocksPerHistogram: Each WOLA block we get an angle estimate for each bin. These are accumulated over BlocksPerHistogram
    WOLA blocks into a histogram. Then the peak of the histogram is output as the angle estimate. Larger values of
    BlocksPerHistogram give more accuracy but slower response time. BlocksPerHistogram value does not affect MIPS.

    DT1: Dynamic thresholding parameter. Controls sensitivity of algorithm to input signal global power. DT1 specifies the
    number of dB above the global threshold the average signal power for this block must be for an angle to be reported. This
    parameter can be used to avoid reporting angles of small background nuisance noises

Type Definition

typedef struct _ModuleSbDOAV2
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    FLOAT32 Fs;                                   // Sample rate of time domain data entering WOLA analysis block
    INT32 fftSize;                                // FFT size used in computing WOLA block
    INT32 micGeometry;                            // Specifies which 4 mic geometry we are working with
    INT32 MultiSource;                            // MultiSource = 1, multiple audio sources reported each block. = 0, one audio source reported
    INT32 OutputAngles;                           // OutputAngles = 0, angles in range 0-360 reported, = 1 180-360 reported
    INT32 LowerBin;                               // Frequ bin index of lowest frequ component in the WOLA block
    FLOAT32 MicGeomSize;                          // Length in meters of each side of square mic array
    FLOAT32 DT1;                                  // Dynamic threshold level
    INT32 BlocksPerHistogram;                     // Number of blocks used to fill histogram before doing smoothing and averaging
    INT32 boxcarDelay;                            // Half length of rectangular window for histogram smoothing
    INT32 gaussDelay;                             // Half length of gaussian window for histogram smoothing
    FLOAT32 gaussSigma;                           // Standard Deviation for Gaussian window
    INT32 NumHistogramStates;                     // Number of full histograms used for temporal averaging
    INT32 numStates;                              // Number of states in state buffer
    INT32 Opt;                                    // Optimization level
    INT32 numMics;                                // Number of microphones for this mic geometry
    INT32 maxDelay;                               // Maximum of gaussDelay, boxcarDelay
    INT32 HistStatePtr;                           // Index of oldest entry in histogram buffer
    INT32 XStatePtr;                              // Index of oldest entry in state buffer
    INT32 blockCtr;                               // Counter to keep track of number of blocks used to update histogram
    INT32 blockCtrReset;                          // Counter to keep track of number of blocks used between reset to zero of Rxx and avgHistogram
    INT32 aboveThresh;                            // Input signal dBA greater than noise floor dBA. Changes once per BlocksPerHistogram blocks
    INT32 doHistSmoothing;                        // Specifies whether to do smoothing of histogram
    INT32 doHistAveraging;                        // Specifies whether to do temporal smoothing of histogram
    INT32 doNFTracking;                           // Specifies whether to do noise floor tracking
    INT32 doOnsetTracking;                        // Specifies whether to do onset tracking
    FLOAT32 speedSound;                           // Speed of sound in m/s
    FLOAT32 Test2Thresh;                          // Threshold for passing square mic array steering vector test 2
    FLOAT32 Test1Thresh;                          // Threshold for passing square mic array steering vector test 1
    FLOAT32 CTFact;                               // Coherence Test Factor, scale factor specifying how much larger dominant eigenvalue must be than the sum of all the other eigenvalues
    FLOAT32 MinPeakThresh;                        // Minimum height of a histogram peak to be eligible to be reported as a DOA
    INT32 MinDist;                                // Distance in integer units of degrees, between peaks in histogram to count as a distinct DOA
    INT32 BlocksPerReset;                         // Number of blocks between resets to zero of Rxx and avgHistogram
    FLOAT32 NFUp;                                 // Noise floor ramp up coefficient
    FLOAT32 NFUpSlow;                             // Noise floor ramp up slow coefficient
    FLOAT32 NFDown;                               // Noise floor ramp down coefficient
    FLOAT32 NFMin;                                // Minimum allowable value for noise floor
    FLOAT32 NFSNR;                                // Noise Floor SNR
    INT32 NFFrameCount;                           // Max number of frames to ramp up fast
    FLOAT32 OSUp;                                 // Onset ramp up coefficient
    FLOAT32 OSDown;                               // Onset ramp down coefficient
    FLOAT32 OSJump;                               // Onset jump coefficient
    INT32 OSDur;                                  // Number of frames for onset decay
    FLOAT32* Rxx;                                 // Holds current estimate of Rxx
    FLOAT32* RxxTemp;                             // Temporary buffer needed for squaring Rxx
    FLOAT32* RxxTemp2;                            // Temporary buffer needed for squaring Rxx
    FLOAT32* XState;                              // Holds numStates sets of numMics input data
    FLOAT32* HistState;                           // Holds NumHistogramStates histograms
    FLOAT32* TempReal;                            // Scratch array of numSB real values
    FLOAT32* noise_floor;                         // Noise floor per bin, array of numSB real values
    INT32* sig_count_bw;                          // Frame count for fast ramp up per bin, array of numSB real values
    FLOAT32* onset_threshold;                     // Onset threshold per bin, array of numSB real values
    INT32* count_onset;                           // Onset count per bin, array of numSB real values
    FLOAT32* xMagAvg;                             // Average magnitude per bin, array of numSB real values
    FLOAT32* NFAvg;                               // Noise floor average per bin, array of numSB real values
    FLOAT32* AWeights;                            // A weighting values
    FLOAT32* TempComplex;                         // Scratch array of numSB complex values
    FLOAT32* EvalEst;                             // Scratch array to hold estimates of dominant eigenvalues
    FLOAT32* Trace;                               // Scratch array to hold trace of Rxx for each subband
    INT32* freqBinMap;                            // Scratch array to hold mapping between valid bins and discrete frquency indices
    FLOAT32* avgHistogram;                        // Scratch array to hold average histogram
    FLOAT32* currentHistogram;                    // Scratch array to hold current histogram
    FLOAT32* smoothedHistogram;                   // Scratch array to hold smoothed histogram
    FLOAT32* histExt;                             // Scratch array to hold smoothed histogram
    FLOAT32* histCnv;                             // Scratch array to hold smoothed histogram
    INT32* histSortedAngles;                      // Scratch array for histogram peak picking
    FLOAT32* histSortedValues;                    // Scratch array for histogram peak picking
    INT32* histAnglesUsed;                        // Scratch array for histogram peak picking
    FLOAT32* valuesOutState;                      // Scratch array to hold output histogram counts
    INT32* anglesOutState;                        // Scratch array to hold output angles
    FLOAT32* GaussianWindow;                      // Gaussian window for smoothing histogram
    FLOAT32* BoxcarWindow;                        // Rectangular window for smoothing histogram
} ModuleSbDOAV2Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
Fs	float	const	0	48000	Unrestricted
fftSize	int	const	0	512	Unrestricted
micGeometry	int	const	0	0	Unrestricted
MultiSource	int	const	0	0	Unrestricted
OutputAngles	int	const	0	0	Unrestricted
LowerBin	int	const	0	0	Unrestricted
MicGeomSize	float	const	0	0.04	Unrestricted
DT1	float	parameter	0	3	-5000:5000
BlocksPerHistogram	int	parameter	0	32	1:200
boxcarDelay	int	const	1	2	Unrestricted
gaussDelay	int	const	1	8	Unrestricted
gaussSigma	float	const	1	3.2	Unrestricted
NumHistogramStates	int	const	1	4	Unrestricted
numStates	int	const	1	4	Unrestricted
Opt	int	const	1	1	0:2
numMics	int	const	1	4	Unrestricted
maxDelay	int	const	1	8	Unrestricted
HistStatePtr	int	state	1	0	Unrestricted
XStatePtr	int	state	1	0	Unrestricted
blockCtr	int	state	1	0	Unrestricted
blockCtrReset	int	state	1	0	Unrestricted
aboveThresh	int	state	1	0	Unrestricted
doHistSmoothing	int	parameter	1	1	Unrestricted
doHistAveraging	int	parameter	1	1	Unrestricted
doNFTracking	int	parameter	1	0	Unrestricted
doOnsetTracking	int	parameter	1	0	Unrestricted
speedSound	float	parameter	1	343	300:400	metersPerSecond
Test2Thresh	float	parameter	1	0.2	0:2
Test1Thresh	float	parameter	1	0.2	0:2
CTFact	float	parameter	1	10	-1:1e+30
MinPeakThresh	float	parameter	1	1	-1:1000000
MinDist	int	parameter	1	10	0:360	degrees
BlocksPerReset	int	parameter	1	100	100:100000
NFUp	float	parameter	1	1.01	0:2
NFUpSlow	float	parameter	1	1.001	0:2
NFDown	float	parameter	1	0.99	0:1
NFMin	float	parameter	1	0.0001	0:1
NFSNR	float	parameter	1	2	0:10
NFFrameCount	int	parameter	1	3	0:100
OSUp	float	parameter	1	1.3	0:10
OSDown	float	parameter	1	0.95	0:1
OSJump	float	parameter	1	1	0:10
OSDur	int	parameter	1	2	0:25
Rxx	float*	state	0	[1024 x 1]	Unrestricted
RxxTemp	float*	state	0	[1024 x 1]	Unrestricted
RxxTemp2	float*	state	0	[1024 x 1]	Unrestricted
XState	float*	state	0	[1024 x 1]	Unrestricted
HistState	float*	state	0	[1440 x 1]	Unrestricted
TempReal	float*	state	0	[32 x 1]	Unrestricted
noise_floor	float*	state	0	[32 x 1]	Unrestricted
sig_count_bw	int*	state	0	[32 x 1]	Unrestricted
onset_threshold	float*	state	0	[32 x 1]	Unrestricted
count_onset	int*	state	0	[32 x 1]	Unrestricted
xMagAvg	float*	state	0	[32 x 1]	Unrestricted
NFAvg	float*	state	0	[32 x 1]	Unrestricted
AWeights	float*	parameter	0	[1 x 257]	Unrestricted
TempComplex	float*	state	0	[64 x 1]	Unrestricted
EvalEst	float*	state	0	[64 x 1]	Unrestricted
Trace	float*	state	0	[64 x 1]	Unrestricted
freqBinMap	int*	state	0	[32 x 1]	Unrestricted
avgHistogram	float*	state	0	[360 x 1]	Unrestricted
currentHistogram	float*	state	0	[360 x 1]	Unrestricted
smoothedHistogram	float*	state	0	[360 x 1]	Unrestricted
histExt	float*	state	0	[376 x 1]	Unrestricted
histCnv	float*	state	0	[392 x 1]	Unrestricted
histSortedAngles	int*	state	0	[360 x 1]	Unrestricted
histSortedValues	float*	state	0	[360 x 1]	Unrestricted
histAnglesUsed	int*	state	0	[360 x 1]	Unrestricted
valuesOutState	float*	state	0	[10 x 1]	Unrestricted
anglesOutState	int*	state	0	[10 x 1]	Unrestricted
GaussianWindow	float*	parameter	0	[17 x 1]	Unrestricted
BoxcarWindow	float*	parameter	0	[5 x 1]	Unrestricted

Pins

Input Pins

Name: Audio
Description: audio input
Data type: float
Channel range: 4
Block size range: Unrestricted
Sample rate range: Unrestricted
Complex support: Complex

Name: BitMap
Description: bit map
Data type: int
Channel range: 1
Block size range: Unrestricted
Sample rate range: Unrestricted
Complex support: Real

Output Pins

Name: Angle
Description: DOA Angle
Data type: float
Name: ConfidenceValue
Description: DOA Confidence Value
Data type: float
Name: Histogram
Description: Histogram Data
Data type: float

MATLAB Usage

File Name: sb_doa_v2_module.m