140 lines
4.9 KiB
Java
140 lines
4.9 KiB
Java
/*
|
|
* Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
|
|
* 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.
|
|
*
|
|
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
* or visit www.oracle.com if you need additional information or have any
|
|
* questions.
|
|
*/
|
|
package com.sun.media.sound;
|
|
|
|
/**
|
|
* Hann windowed sinc interpolation resampler with anti-alias filtering.
|
|
*
|
|
* Using 30 points for the interpolation.
|
|
*
|
|
* @author Karl Helgason
|
|
*/
|
|
public final 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;
|
|
|
|
}
|
|
}
|