Android Open Source - voicesmith Separation Processor

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From Project

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License

The source code is released under:

GNU General Public License

Java Source Code

/*
 * Voicesmith <http://voicesmith.jurihock.de/>
 */*w  w  w .  j a  va 2 s.co m*/
 * Copyright (c) 2011-2014 Juergen Hock
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package de.jurihock.voicesmith.dsp.processors;

import static de.jurihock.voicesmith.dsp.Math.PI;
import static de.jurihock.voicesmith.dsp.Math.abs;
import static de.jurihock.voicesmith.dsp.Math.arg;
import static de.jurihock.voicesmith.dsp.Math.imag;
import static de.jurihock.voicesmith.dsp.Math.princarg;
import static de.jurihock.voicesmith.dsp.Math.real;

public final class SeparationProcessor
{
  private final int    fftSize;
  private final float[]  omega;
  private final float[]  prevPhase1;
  private final float[]  prevPhase2;

  public SeparationProcessor(int frameSize, int hopSize)
  {
    fftSize = frameSize / 2;
    omega = new float[fftSize];
    prevPhase1 = new float[fftSize];
    prevPhase2 = new float[fftSize];

    for (int i = 0; i < fftSize; i++)
    {
      omega[i] = 2 * PI * (i / (float) frameSize) // not fftSize!
        * (float) hopSize;
    }
  }

  public void processFrame(float[] frame)
  {
    final int fftSize = frame.length / 2;
    float re, im, abs, nextPhase, phaseDelta;

    for (int i = 1; i < fftSize; i++)
    {
      // Get source Re and Im parts
      re = frame[2 * i];
      im = frame[2 * i + 1];
      abs = abs(re, im);

      // Invert phase value
      nextPhase = arg(re, im);

      // Compute phase delta
      phaseDelta = princarg(nextPhase - 2F * prevPhase1[i] + prevPhase2[i]);
      
      // Disable some frequency components
      if(Math.abs(phaseDelta) > 0.05F * omega[i])
      {
        abs = 0;
        nextPhase = 0;
      }
      
      // Save phase values
      prevPhase2[i] = prevPhase1[i];
      prevPhase1[i] = nextPhase;

      // Compute destination Re and Im parts
      frame[2 * i] = real(abs, nextPhase);
      frame[2 * i + 1] = imag(abs, nextPhase);
    }
  }
}

Java Source Code List

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