listeners = new ArrayList<>();
@@ -43,9 +41,6 @@ public class FrequencyAnalyser implements Runnable {
@Override
public void run() {
double[] buf = new double[2 << (powerOfTwo - 1)];
- float[] leftSamples = new float[buf.length / 2];
- float[] rightSamples = new float[buf.length / 2];
- PitchDetector pitchDetector = new DynamicWavelet(sampleRate, buf.length / 2);
while (!stopped) {
try {
@@ -53,15 +48,39 @@ public class FrequencyAnalyser implements Runnable {
} catch (InterruptedException e) {
logger.log(Level.SEVERE, e.getMessage(), e);
}
+ double[] leftSamples = new double[buf.length / 2];
+ double[] rightSamples = new double[buf.length / 2];
for (int i = 0; i < buf.length; i += 2) {
- leftSamples[i / 2] = (float) buf[i];
- rightSamples[i / 2] = (float) buf[i + 1];
+ leftSamples[i / 2] = buf[i];
+ rightSamples[i / 2] = buf[i + 1];
}
- PitchDetectionResult leftFrequency = pitchDetector.getPitch(leftSamples);
- PitchDetectionResult rightFrequency = pitchDetector.getPitch(rightSamples);
+ FFT leftFft = new FFT(leftSamples, null, false, true);
+ FFT rightFft = new FFT(rightSamples, null, false, true);
- notifyListeners(leftFrequency.getPitch(), rightFrequency.getPitch());
+ double[] leftMags = leftFft.getMagnitudeSpectrum();
+ double[] rightMags = rightFft.getMagnitudeSpectrum();
+ double[] bins = leftFft.getBinLabels(sampleRate);
+
+ int maxLeftIndex = 0;
+ double maxLeft = Double.NEGATIVE_INFINITY;
+ int maxRightIndex = 0;
+ double maxRight = Double.NEGATIVE_INFINITY;
+ for (int i = 0; i < leftMags.length; i++) {
+ if (bins[i] < 20 || bins[i] > 20000) {
+ continue;
+ }
+ if (leftMags[i] > maxLeft) {
+ maxLeftIndex = i;
+ maxLeft = leftMags[i];
+ }
+ if (rightMags[i] > maxRight) {
+ maxRightIndex = i;
+ maxRight = rightMags[i];
+ }
+ }
+
+ notifyListeners(bins[maxLeftIndex], bins[maxRightIndex]);
}
}
diff --git a/src/main/java/sh/ball/math/fft/FFT.java b/src/main/java/sh/ball/math/fft/FFT.java
new file mode 100644
index 00000000..59d20721
--- /dev/null
+++ b/src/main/java/sh/ball/math/fft/FFT.java
@@ -0,0 +1,894 @@
+/*
+ * @(#)FFT.java 1.0 April 5, 2005.
+ *
+ * Cory McKay
+ * McGill Univarsity
+ *
+ * https://sourceforge.net/p/jaudio/svn/2/tree/jAudio%201.0/src/jAudioFeatureExtractor/jAudioTools/FFT.java
+ *
+
+ LICENSE copied from https://github.com/dmcennis/jAudioGIT/blob/master/License.txt
+
+ GNU LESSER GENERAL PUBLIC LICENSE
+ Version 2.1, February 1999
+
+ Copyright (C) 1991, 1999 Free Software Foundation, Inc.
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+
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+ the version number 2.1.)
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+ How to Apply These Terms to Your New Libraries
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+"copyright" line and a pointer to where the full notice is found.
+
+ jAudio DSP package
+ Copyright (C) 2005 Danie McEnnis, Cory McKay, University of McGill
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
+ USA
+
+Daniel McEnnis: maintainer
+dmcennis@gmail.com
+160 Johnson St
+Marion OH 43302
+ */
+
+package sh.ball.math.fft;
+
+
+/**
+ * This class performs a complex to complex Fast Fourier Transform. Forward and inverse
+ * transforms may both be performed. The transforms may be performed with or without
+ * the application of a Hanning window.
+ *
+ * The FFT is performed by this class' constructor. The real and imaginary results
+ * are both stored, and the magnitude spectrum, power spectrum and phase angles may
+ * also be accessed (along with appropriate frequency bin labels for the magnitude
+ * and power spectra).
+ *
+ * @author Cory McKay
+ */
+public class FFT
+{
+ /* FIELDS ******************************************************************/
+
+
+ // The results of the FFT.
+ private double[] real_output;
+ private double[] imaginary_output;
+
+ // The phase angles
+ private double[] output_angle;
+
+ // Magnitude and power spectra
+ private double[] output_magnitude;
+ private double[] output_power;
+
+
+ /* CONSTRUCTOR *************************************************************/
+
+
+ /**
+ * Performs the Fourier transform and stores the real and imaginary results.
+ * Input signals are zero-padded if they do not have a length equal to a
+ * power of 2.
+ *
+ * @param real_input The real part of the signal to be transformed.
+ * @param imaginary_input The imaginary part of the signal to be.
+ * transformed. This may be null if the signal
+ * is entirely real.
+ * @param inverse_transform A value of false implies that a forward
+ * transform is to be applied, and a value of
+ * true means that an inverse transform is tob
+ * be applied.
+ * @param use_hanning_window A value of true means that a Hanning window
+ * will be applied to the real_input. A value
+ * of valse will result in the application of
+ * a Hanning window.
+ * @throws Exception Throws an exception if the real and imaginary
+ * inputs are of different sizes or if less than
+ * three input samples are provided.
+ */
+ public FFT( double[] real_input,
+ double[] imaginary_input,
+ boolean inverse_transform,
+ boolean use_hanning_window ) {
+ // Throw an exception if non-matching input signals are provided
+ if (imaginary_input != null)
+ if (real_input.length != imaginary_input.length)
+ throw new RuntimeException("Imaginary and real inputs are of different sizes.");
+
+ // Throw an exception if less than three samples are provided
+ if (real_input.length < 3)
+ throw new RuntimeException( "Only " + real_input.length + " samples provided.\n" +
+ "At least three are needed." );
+
+ // Verify that the input size has a number of samples that is a
+ // power of 2. If not, then increase the size of the array using
+ // zero-padding. Also creates a zero filled imaginary component
+ // of the input if none was specified.
+ int valid_size = ensureIsPowerOfN(real_input.length, 2);
+ if (valid_size != real_input.length)
+ {
+ double[] temp = new double[valid_size];
+ for (int i = 0; i < real_input.length; i++)
+ temp[i] = real_input[i];
+ for (int i = real_input.length; i < valid_size; i++)
+ temp[i] = 0.0;
+ real_input = temp;
+
+ if (imaginary_input == null)
+ {
+ imaginary_input = new double[valid_size];
+ for (int i = 0; i < imaginary_input.length; i++)
+ imaginary_input[i] = 0.0;
+ }
+ else
+ {
+ temp = new double[valid_size];
+ for (int i = 0; i < imaginary_input.length; i++)
+ temp[i] = imaginary_input[i];
+ for (int i = imaginary_input.length; i < valid_size; i++)
+ temp[i] = 0.0;
+ imaginary_input = temp;
+ }
+ }
+ else if (imaginary_input == null)
+ {
+ imaginary_input = new double[valid_size];
+ for (int i = 0; i < imaginary_input.length; i++)
+ imaginary_input[i] = 0.0;
+ }
+
+ // Instantiate the arrays to hold the output and copy the input
+ // to them, since the algorithm used here is self-processing
+ real_output = new double[valid_size];
+ System.arraycopy(real_input, 0, real_output, 0, valid_size);
+ imaginary_output = new double[valid_size];
+ System.arraycopy(imaginary_input, 0, imaginary_output, 0, valid_size);
+
+ // Apply a Hanning window to the real values if this option is
+ // selected
+ if (use_hanning_window)
+ {
+ for (int i = 0; i < real_output.length; i++)
+ {
+ double hanning = 0.5 - 0.5 * Math.cos(2 * Math.PI * i / valid_size);
+ real_output[i] *= hanning;
+ }
+ }
+
+ // Determine whether this is a forward or inverse transform
+ int forward_transform = 1;
+ if (inverse_transform)
+ forward_transform = -1;
+
+ // Reorder the input data into reverse binary order
+ double scale = 1.0;
+ int j = 0;
+ for (int i = 0; i < valid_size; ++i)
+ {
+ if (j >= i)
+ {
+ double tempr = real_output[j] * scale;
+ double tempi = imaginary_output[j] * scale;
+ real_output[j] = real_output[i] * scale;
+ imaginary_output[j] = imaginary_output[i] * scale;
+ real_output[i] = tempr;
+ imaginary_output[i] = tempi;
+ }
+ int m = valid_size / 2;
+ while (m >= 1 && j >= m)
+ {
+ j -= m;
+ m /= 2;
+ }
+ j += m;
+ }
+
+ // Perform the spectral recombination stage by stage
+ int stage = 0;
+ int max_spectra_for_stage;
+ int step_size;
+ for( max_spectra_for_stage = 1, step_size = 2 * max_spectra_for_stage;
+ max_spectra_for_stage < valid_size;
+ max_spectra_for_stage = step_size, step_size = 2 * max_spectra_for_stage)
+ {
+ double delta_angle = forward_transform * Math.PI / max_spectra_for_stage;
+
+ // Loop once for each individual spectra
+ for (int spectra_count = 0; spectra_count < max_spectra_for_stage; ++spectra_count)
+ {
+ double angle = spectra_count * delta_angle;
+ double real_correction = Math.cos(angle);
+ double imag_correction = Math.sin(angle);
+
+ int right = 0;
+ for (int left = spectra_count; left < valid_size; left += step_size)
+ {
+ right = left + max_spectra_for_stage;
+ double temp_real = real_correction * real_output[right] -
+ imag_correction * imaginary_output[right];
+ double temp_imag = real_correction * imaginary_output[right] +
+ imag_correction * real_output[right];
+ real_output[right] = real_output[left] - temp_real;
+ imaginary_output[right] = imaginary_output[left] - temp_imag;
+ real_output[left] += temp_real;
+ imaginary_output[left] += temp_imag;
+ }
+ }
+ max_spectra_for_stage = step_size;
+ }
+
+ // Set the angle and magnitude to null originally
+ output_angle = null;
+ output_power = null;
+ output_magnitude = null;
+ }
+
+ /* PUBLIC METHODS **********************************************************/
+
+ /**
+ * Returns the magnitudes spectrum. It only makes sense to call
+ * this method if this object was instantiated as a forward Fourier
+ * transform.
+ *
+ *
Only the left side of the spectrum is returned, as the folded
+ * portion of the spectrum is redundant for the purpose of the magnitude
+ * spectrum. This means that the bins only go up to half of the
+ * sampling rate.
+ *
+ * @return The magnitude of each frequency bin.
+ */
+ public double[] getMagnitudeSpectrum()
+ {
+ // Only calculate the magnitudes if they have not yet been calculated
+ if (output_magnitude == null)
+ {
+ int number_unfolded_bins = imaginary_output.length / 2;
+ output_magnitude = new double[number_unfolded_bins];
+ for(int i = 0; i < output_magnitude.length; i++)
+ output_magnitude[i] = ( Math.sqrt(real_output[i] * real_output[i] + imaginary_output[i] * imaginary_output[i]) ) / real_output.length;
+ }
+
+ // Return the magnitudes
+ return output_magnitude;
+ }
+
+
+ /**
+ * Returns the power spectrum. It only makes sense to call
+ * this method if this object was instantiated as a forward Fourier
+ * transform.
+ *
+ *
Only the left side of the spectrum is returned, as the folded
+ * portion of the spectrum is redundant for the purpose of the power
+ * spectrum. This means that the bins only go up to half of the
+ * sampling rate.
+ *
+ * @return The magnitude of each frequency bin.
+ */
+ public double[] getPowerSpectrum()
+ {
+ // Only calculate the powers if they have not yet been calculated
+ if (output_power == null)
+ {
+ int number_unfolded_bins = imaginary_output.length / 2;
+ output_power = new double[number_unfolded_bins];
+ for(int i = 0; i < output_power.length; i++)
+ output_power[i] = (real_output[i] * real_output[i] + imaginary_output[i] * imaginary_output[i]) / real_output.length;
+ }
+
+ // Return the power
+ return output_power;
+ }
+
+
+ /**
+ * Returns the phase angle for each frequency bin. It only makes sense to
+ * call this method if this object was instantiated as a forward Fourier
+ * transform.
+ *
+ *
Only the left side of the spectrum is returned, as the folded
+ * portion of the spectrum is redundant for the purpose of the phase
+ * angles. This means that the bins only go up to half of the
+ * sampling rate.
+ *
+ * @return The phase angle for each frequency bin in degrees.
+ */
+ public double[] getPhaseAngles()
+ {
+ // Only calculate the angles if they have not yet been calculated
+ if (output_angle == null)
+ {
+ int number_unfolded_bins = imaginary_output.length / 2;
+ output_angle = new double[number_unfolded_bins];
+ for(int i = 0; i < output_angle.length; i++)
+ {
+ if(imaginary_output[i] == 0.0 && real_output[i] == 0.0)
+ output_angle[i] = 0.0;
+ else
+ output_angle[i] = Math.atan(imaginary_output[i] / real_output[i]) * 180.0 / Math.PI;
+
+ if(real_output[i] < 0.0 && imaginary_output[i] == 0.0)
+ output_angle[i] = 180.0;
+ else if(real_output[i] < 0.0 && imaginary_output[i] == -0.0)
+ output_angle[i] = -180.0;
+ else if(real_output[i] < 0.0 && imaginary_output[i] > 0.0)
+ output_angle[i] += 180.0;
+ else if(real_output[i] < 0.0 && imaginary_output[i] < 0.0)
+ output_angle[i] += -180.0;
+ }
+ }
+
+ // Return the phase angles
+ return output_angle;
+ }
+
+
+ /**
+ * Returns the frequency bin labels for each bin referred to by the
+ * real values, imaginary values, magnitudes and phase angles as
+ * determined by the given sampling rate.
+ *
+ * @param sampling_rate The sampling rate that was used to perform
+ * the FFT.
+ * @return The bin labels.
+ */
+ public double[] getBinLabels(double sampling_rate)
+ {
+ int number_bins = real_output.length;
+ double bin_width = sampling_rate / (double) number_bins;
+ int number_unfolded_bins = imaginary_output.length / 2;
+ double[] labels = new double[number_unfolded_bins];
+ labels[0] = 0.0;
+ for (int bin = 1; bin < labels.length; bin++)
+ labels[bin] = bin * bin_width;
+ return labels;
+ }
+
+
+ /**
+ * Returns the real values as calculated by the FFT.
+ *
+ * @return The real values.
+ */
+ public double[] getRealValues()
+ {
+ return real_output;
+ }
+
+
+ /**
+ * Returns the real values as calculated by the FFT.
+ *
+ * @return The real values.
+ */
+ public double[] getImaginaryValues()
+ {
+ return imaginary_output;
+ }
+
+ /* PRIVATE METHODS *********************************************************/
+
+ /**
+ * If the given x is a power of the given n, then x is returned.
+ * If not, then the next value above the given x that is a power
+ * of n is returned.
+ *
+ *
IMPORTANT: Both x and n must be greater than zero.
+ *
+ * @param x The value to ensure is a power of n.
+ * @param n The power to base x's validation on.
+ */
+ private static int ensureIsPowerOfN(int x, int n)
+ {
+ double log_value = logBaseN((double) x, (double) n);
+ int log_int = (int) log_value;
+ int valid_size = pow(n, log_int);
+ if (valid_size != x)
+ valid_size = pow(n, log_int + 1);
+ return valid_size;
+ }
+
+ /**
+ * Returns the logarithm of the specified base of the given number.
+ *
+ *
IMPORTANT: Both x and n must be greater than zero.
+ *
+ * @param x The value to find the log of.
+ * @param n The base of the logarithm.
+ */
+ private static double logBaseN(double x, double n)
+ {
+ return (Math.log10(x) / Math.log10(n));
+ }
+
+ /**
+ * Returns the given a raised to the power of the given b.
+ *
+ *
IMPORTANT: b must be greater than zero.
+ *
+ * @param a The base.
+ * @param b The exponent.
+ */
+ private static int pow(int a, int b)
+ {
+ int result = a;
+ for (int i = 1; i < b; i++)
+ result *= a;
+ return result;
+ }
+}
\ No newline at end of file