Class DSP_Frames

Digital signal processing methods.

Inheritance

Object

DSP_Frames

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: AudioAnalysisTools.DSP

Assembly: AudioAnalysisTools.dll

Syntax

public static class DSP_Frames

Fields

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Pi

Declaration

public const double Pi = 3.1415926535897931

Field Value

Type	Description
Double

Methods

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ConvertSamples2Milliseconds(Double[], Int32)

Declaration

public static double[] ConvertSamples2Milliseconds(double[] sampleCounts, int sampleRate)

Parameters

Type	Name	Description
Double[]	sampleCounts
Int32	sampleRate

Returns

Type	Description
Double[]

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ConvertZeroCrossings2Hz(Double[], Int32, Int32)

Declaration

public static int[] ConvertZeroCrossings2Hz(double[] zeroCrossings, int frameWidth, int sampleRate)

Parameters

Type	Name	Description
Double[]	zeroCrossings
Int32	frameWidth
Int32	sampleRate

Returns

Type	Description
Int32[]

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DisplaySignal(Double[])

Declaration

public static void DisplaySignal(double[] sig)

Parameters

Type	Name	Description
Double[]	sig

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DisplaySignal(Double[], Boolean)

Declaration

public static void DisplaySignal(double[] sig, bool showIndex)

Parameters

Type	Name	Description
Double[]	sig
Boolean	showIndex

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ExtractEnvelopeAndAmplSpectrogram(Double[], Int32, Double, Boolean, Int32, Double)

Calling this method sets the default FFT window, currently HANNING - see FFT.cs line 22. Same as previous method but use frame overlap (a double) as an argument rather than framestep (an integer).

Declaration

public static DSP_Frames.EnvelopeAndFft ExtractEnvelopeAndAmplSpectrogram(double[] signal, int sampleRate, double epsilon, bool doPreemphasis, int frameSize, double overlap)

Parameters

Type	Name	Description
Double[]	signal
Int32	sampleRate
Double	epsilon
Boolean	doPreemphasis
Int32	frameSize
Double	overlap

Returns

Type	Description
DSP_Frames.EnvelopeAndFft

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ExtractEnvelopeAndAmplSpectrogram(Double[], Int32, Double, Boolean, Int32, Int32, String)

Returns the following 18 values encapsulated in class EnvelopeAndFft

the minimum and maximum signal values
the average of absolute amplitudes for each frame
the minimum value in each frame
the maximum value in each frame.
the signal envelope as vector. i.e. the maximum of absolute amplitudes for each frame.
vector of frame energies
the high amplitude and clipping counts
the signal amplitude spectrogram
the power of the FFT Window, i.e. sum of squared window values.
the nyquist
the width of freq bin in Hz
the Nyquist bin ID AND OTHERS The returned info is used by Sonogram classes to draw sonograms and by Spectral Indices classes to calculate Spectral indices. Less than half the info is used to draw sonograms but it is difficult to disentangle calculation of all the info without reverting back to the old days when we used two classes and making sure they remain in synch.

Declaration

public static DSP_Frames.EnvelopeAndFft ExtractEnvelopeAndAmplSpectrogram(double[] signal, int sampleRate, double epsilon, bool doPreemphasis, int frameSize, int frameStep, string windowName = null)

Parameters

Type	Name	Description
Double[]	signal
Int32	sampleRate
Double	epsilon
Boolean	doPreemphasis
Int32	frameSize
Int32	frameStep
String	windowName

Returns

Type	Description
DSP_Frames.EnvelopeAndFft

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ExtractEnvelopeAndFfts(AudioRecording, Boolean, Int32, Double, String)

Calling this method will set default FFT window if windowName is null. Otherwise sets the FFT window specified in the config file.

Declaration

public static DSP_Frames.EnvelopeAndFft ExtractEnvelopeAndFfts(AudioRecording recording, bool doPreemphasis, int frameSize, double overlap, string windowName = null)

Parameters

Type	Name	Description
AudioRecording	recording
Boolean	doPreemphasis
Int32	frameSize
Double	overlap
String	windowName

Returns

Type	Description
DSP_Frames.EnvelopeAndFft

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ExtractEnvelopeAndFfts(AudioRecording, Boolean, Int32, Int32)

Calling this method sets the default FFT window, currently HANNING - see FFT.cs line 22.

Declaration

public static DSP_Frames.EnvelopeAndFft ExtractEnvelopeAndFfts(AudioRecording recording, bool doPreemphasis, int frameSize, int frameStep)

Parameters

Type	Name	Description
AudioRecording	recording
Boolean	doPreemphasis
Int32	frameSize
Int32	frameStep

Returns

Type	Description
DSP_Frames.EnvelopeAndFft

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ExtractEnvelopeAndZeroCrossings(Double[], Int32, Int32, Double)

Declaration

public static Tuple<double[], double[], double[], double[], double[]> ExtractEnvelopeAndZeroCrossings(double[] signal, int sr, int windowSize, double overlap)

Parameters

Type	Name	Description
Double[]	signal
Int32	sr
Int32	windowSize
Double	overlap

Returns

Type	Description
Tuple<Double[], Double[], Double[], Double[], Double[]>

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Frames(Double[], Int32[,])

Returns the signal broken into frames. This method is not called because the only reason to break a signal into frames is to do fft on the frames.

Declaration

public static double[, ] Frames(double[] data, int[, ] startEnds)

Parameters

Type	Name	Description
Double[]	data
Int32[,]	startEnds

Returns

Type	Description
Double[,]

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FrameStartEnds(Int32, Int32, Double)

Declaration

public static int[, ] FrameStartEnds(int dataLength, int frameSize, double windowOverlap)

Parameters

Type	Name	Description
Int32	dataLength
Int32	frameSize
Double	windowOverlap

Returns

Type	Description
Int32[,]

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FrameStartEnds(Int32, Int32, Int32)

Returns the start and end index of all frames in a long audio signal.

Declaration

public static int[, ] FrameStartEnds(int dataLength, int frameSize, int frameStep)

Parameters

Type	Name	Description
Int32	dataLength
Int32	frameSize
Int32	frameStep

Returns

Type	Description
Int32[,]

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FrameStep(Int32, Double)

Declaration

public static int FrameStep(int windowSize, double windowOverlap)

Parameters

Type	Name	Description
Int32	windowSize
Double	windowOverlap

Returns

Type	Description
Int32

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SignalEnvelope(Double[,], out Double[], out Double[])

returns the min and max values in each frame. Signal values range from -1 to +1.

Declaration

public static void SignalEnvelope(double[, ] frames, out double[] minAmp, out double[] maxAmp)

Parameters

Type	Name	Description
Double[,]	frames
Double[]	minAmp
Double[]	maxAmp

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ZeroCrossings(Double[,])

counts the zero crossings in each frame This info is used for determining the begin and end points for vocalizations.

Declaration

public static int[] ZeroCrossings(double[, ] frames)

Parameters

Type	Name	Description
Double[,]	frames

Returns

Type	Description
Int32[]