1 /* 2 * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package com.sun.media.sound; 26 27 /** 28 * A resampler that uses first-order (linear) interpolation. 29 * 30 * This one doesn't perform float to int casting inside the processing loop. 31 * 32 * @author Karl Helgason 33 */ 34 public final class SoftLinearResampler2 extends SoftAbstractResampler { 35 36 public int getPadding() { 37 return 2; 38 } 39 40 public void interpolate(float[] in, float[] in_offset, float in_end, 41 float[] startpitch, float pitchstep, float[] out, int[] out_offset, 42 int out_end) { 43 44 float pitch = startpitch[0]; 45 float ix = in_offset[0]; 46 int ox = out_offset[0]; 47 float ix_end = in_end; 48 int ox_end = out_end; 49 50 // Check if we have do anything 51 if (!(ix < ix_end && ox < ox_end)) 52 return; 53 54 // 15 bit shift was choosed because 55 // it resulted in no drift between p_ix and ix. 56 int p_ix = (int) (ix * (1 << 15)); 57 int p_ix_end = (int) (ix_end * (1 << 15)); 58 int p_pitch = (int) (pitch * (1 << 15)); 59 // Pitch needs to recalculated 60 // to ensure no drift between p_ix and ix. 61 pitch = p_pitch * (1f / (1 << 15)); 62 63 if (pitchstep == 0f) { 64 65 // To reduce 66 // while (p_ix < p_ix_end && ox < ox_end) 67 // into 68 // while (ox < ox_end) 69 // We need to calculate new ox_end value. 70 int p_ix_len = p_ix_end - p_ix; 71 int p_mod = p_ix_len % p_pitch; 72 if (p_mod != 0) 73 p_ix_len += p_pitch - p_mod; 74 int ox_end2 = ox + p_ix_len / p_pitch; 75 if (ox_end2 < ox_end) 76 ox_end = ox_end2; 77 78 while (ox < ox_end) { 79 int iix = p_ix >> 15; 80 float fix = ix - iix; 81 float i = in[iix]; 82 out[ox++] = i + (in[iix + 1] - i) * fix; 83 p_ix += p_pitch; 84 ix += pitch; 85 } 86 87 } else { 88 89 int p_pitchstep = (int) (pitchstep * (1 << 15)); 90 pitchstep = p_pitchstep * (1f / (1 << 15)); 91 92 while (p_ix < p_ix_end && ox < ox_end) { 93 int iix = p_ix >> 15; 94 float fix = ix - iix; 95 float i = in[iix]; 96 out[ox++] = i + (in[iix + 1] - i) * fix; 97 ix += pitch; 98 p_ix += p_pitch; 99 pitch += pitchstep; 100 p_pitch += p_pitchstep; 101 } 102 } 103 in_offset[0] = ix; 104 out_offset[0] = ox; 105 startpitch[0] = pitch; 106 107 } 108 }