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    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    *
    * This code is free software; you can redistribute it and/or modify it
    * under the terms of the GNU General Public License version 2 only, as
    * published by the Free Software Foundation.  Oracle designates this
    * particular file as subject to the "Classpath" exception as provided
    * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code 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
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  package com.sun.media.sound;
  
  /**
   * Hann windowed sinc interpolation resampler with anti-alias filtering.
   *
   * Using 30 points for the interpolation.
   *
   * @author Karl Helgason
   */
  public class SoftSincResampler extends SoftAbstractResampler {
  
      float[][][] sinc_table;
      int sinc_scale_size = 100;
      int sinc_table_fsize = 800;
      int sinc_table_size = 30;
      int sinc_table_center = sinc_table_size / 2;
  
      public SoftSincResampler() {
          super();
          sinc_table = new float[sinc_scale_size][sinc_table_fsize][];
          for (int s = 0; s < sinc_scale_size; s++) {
              float scale = (float) (1.0 / (1.0 + Math.pow(s, 1.1) / 10.0));
              for (int i = 0; i < sinc_table_fsize; i++) {
                  sinc_table[s][i] = sincTable(sinc_table_size,
                          -i / ((float)sinc_table_fsize), scale);
              }
          }
      }
  
      // Normalized sinc function
      public static double sinc(double x) {
          return (x == 0.0) ? 1.0 : Math.sin(Math.PI * x) / (Math.PI * x);
      }
  
      // Generate hann window suitable for windowing sinc
      public static float[] wHanning(int size, float offset) {
          float[] window_table = new float[size];
          for (int k = 0; k < size; k++) {
              window_table[k] = (float)(-0.5
                      * Math.cos(2.0 * Math.PI * (double)(k + offset)
                          / (double) size) + 0.5);
          }
          return window_table;
      }
  
      // Generate sinc table
      public static float[] sincTable(int size, float offset, float scale) {
          int center = size / 2;
          float[] w = wHanning(size, offset);
          for (int k = 0; k < size; k++)
              w[k] *= sinc((-center + k + offset) * scale) * scale;
          return w;
      }
  
      public int getPadding() // must be at least half of sinc_table_size
      {
          return sinc_table_size / 2 + 2;
      }
  
      public void interpolate(float[] in, float[] in_offset, float in_end,
              float[] startpitch, float pitchstep, float[] out, int[] out_offset,
              int out_end) {
          float pitch = startpitch[0];
          float ix = in_offset[0];
          int ox = out_offset[0];
          float ix_end = in_end;
          int ox_end = out_end;
          int max_p = sinc_scale_size - 1;
          if (pitchstep == 0) {
  
              int p = (int) ((pitch - 1) * 10.0f);
              if (p < 0)
                  p = 0;
              else if (p > max_p)
                  p = max_p;
             float[][] sinc_table_f = this.sinc_table[p];
             while (ix < ix_end && ox < ox_end) {
                 int iix = (int) ix;
                 float[] sinc_table =
                         sinc_table_f[(int)((ix - iix) * sinc_table_fsize)];
                 int xx = iix - sinc_table_center;
                 float y = 0;
                 for (int i = 0; i < sinc_table_size; i++, xx++)
                     y += in[xx] * sinc_table[i];
                 out[ox++] = y;
                 ix += pitch;
             }
         } else {
             while (ix < ix_end && ox < ox_end) {
                 int iix = (int) ix;
                 int p = (int) ((pitch - 1) * 10.0f);
                 if (p < 0)
                     p = 0;
                 else if (p > max_p)
                     p = max_p;
                 float[][] sinc_table_f = this.sinc_table[p];
 
                 float[] sinc_table =
                         sinc_table_f[(int)((ix - iix) * sinc_table_fsize)];
                 int xx = iix - sinc_table_center;
                 float y = 0;
                 for (int i = 0; i < sinc_table_size; i++, xx++)
                     y += in[xx] * sinc_table[i];
                 out[ox++] = y;
 
                 ix += pitch;
                 pitch += pitchstep;
             }
         }
         in_offset[0] = ix;
         out_offset[0] = ox;
         startpitch[0] = pitch;
 
     }
 }