/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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,
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*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.media.sound;
/**
* A resampler that uses third-order (cubic) interpolation.
*
* @author Karl Helgason
*/
public final class SoftCubicResampler extends SoftAbstractResampler {
public int getPadding() {
return 3;
}
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;
if (pitchstep == 0) {
while (ix < ix_end && ox < ox_end) {
int iix = (int) ix;
float fix = ix - iix;
float y0 = in[iix - 1];
float y1 = in[iix];
float y2 = in[iix + 1];
float y3 = in[iix + 2];
float a0 = y3 - y2 + y1 - y0;
float a1 = y0 - y1 - a0;
float a2 = y2 - y0;
float a3 = y1;
//float fix2 = fix * fix;
//out[ox++] = (a0 * fix + a1) * fix2 + (a2 * fix + a3);
out[ox++] = ((a0 * fix + a1) * fix + a2) * fix + a3;
ix += pitch;
}
} else {
while (ix < ix_end && ox < ox_end) {
int iix = (int) ix;
float fix = ix - iix;
float y0 = in[iix - 1];
float y1 = in[iix];
float y2 = in[iix + 1];
float y3 = in[iix + 2];
float a0 = y3 - y2 + y1 - y0;
float a1 = y0 - y1 - a0;
float a2 = y2 - y0;
float a3 = y1;
//float fix2 = fix * fix;
//out[ox++] = (a0 * fix + a1) * fix2 + (a2 * fix + a3);
out[ox++] = ((a0 * fix + a1) * fix + a2) * fix + a3;
ix += pitch;
pitch += pitchstep;
}
}
in_offset[0] = ix;
out_offset[0] = ox;
startpitch[0] = pitch;
}
}