Android Open Source - voicesmith Timescale Processor

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License

The source code is released under:

GNU General Public License

Java Source Code

/*
 * Voicesmith <http://voicesmith.jurihock.de/>
 *// w ww .j a  va  2s.com
 * 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.atan2;
import static de.jurihock.voicesmith.dsp.Math.cos;
import static de.jurihock.voicesmith.dsp.Math.princarg;
import static de.jurihock.voicesmith.dsp.Math.sin;
import static de.jurihock.voicesmith.dsp.Math.sqrt;
import de.jurihock.voicesmith.Disposable;

/**
 * Replaced by the NativeTimescaleProcessor.
 * */
@Deprecated
public final class TimescaleProcessor implements Disposable
{
  private final int      fftSize;
  private final float      timescaleRatio;

  private final float[]    omegaA;
  private final float[]    omegaS;
  private final float[]    prevPhaseA;
  private final float[]    prevPhaseS;

  public TimescaleProcessor(int frameSize, int analysisHopSize, int synthesisHopSize)
  {
    fftSize = frameSize / 2;
    timescaleRatio = (float) synthesisHopSize / (float) analysisHopSize;

    omegaA = new float[fftSize];
    omegaS = new float[fftSize];
    prevPhaseA = new float[fftSize];
    prevPhaseS = new float[fftSize];

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

      omegaS[i] = 2 * PI * (i / (float) frameSize) // not fftSize!
        * (float) synthesisHopSize;
    }
  }

  public void processFrame(float[] frame)
  {
    if (timescaleRatio == 1)
      return;

    float re, im, abs;
    float nextPhaseA, nextPhaseS;
    float phaseDeltaA, phaseDeltaS;

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

      // Compute source phase
      nextPhaseA = atan2(im, re);

      if (timescaleRatio < 2)
      {
        // Compute phase deltas
        phaseDeltaA = princarg(nextPhaseA - (prevPhaseA[i] + omegaA[i]));
        phaseDeltaS = phaseDeltaA * timescaleRatio;
  
        // Compute destination phase
        nextPhaseS = princarg((prevPhaseS[i] + omegaS[i]) + phaseDeltaS);
  
        // Save computed phase values
        prevPhaseA[i] = nextPhaseA;
        prevPhaseS[i] = nextPhaseS;
      }
      else
      {
        // Compute destination phase
        nextPhaseS = princarg(nextPhaseA * 2);
      }

      // Compute destination Re and Im parts
      abs = sqrt(re * re + im * im);
      re = abs * cos(nextPhaseS);
      im = abs * sin(nextPhaseS);

      // Save new values
      frame[2 * i] = re;
      frame[2 * i + 1] = im;
    }
  }

  public void dispose()
  {
  }
}

Java Source Code List

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