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comparison: media/libsoundtouch/src/InterpolateCubic.cpp
media/libsoundtouch/src/InterpolateCubic.cpp
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| -1:000000000000 | 0:26be50b35ef9 |
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| 1 //////////////////////////////////////////////////////////////////////////////// | |
| 2 /// | |
| 3 /// Cubic interpolation routine. | |
| 4 /// | |
| 5 /// Author : Copyright (c) Olli Parviainen | |
| 6 /// Author e-mail : oparviai 'at' iki.fi | |
| 7 /// SoundTouch WWW: http://www.surina.net/soundtouch | |
| 8 /// | |
| 9 //////////////////////////////////////////////////////////////////////////////// | |
| 10 // | |
| 11 // $Id: InterpolateCubic.cpp 179 2014-01-06 18:41:42Z oparviai $ | |
| 12 // | |
| 13 //////////////////////////////////////////////////////////////////////////////// | |
| 14 // | |
| 15 // License : | |
| 16 // | |
| 17 // SoundTouch audio processing library | |
| 18 // Copyright (c) Olli Parviainen | |
| 19 // | |
| 20 // This library is free software; you can redistribute it and/or | |
| 21 // modify it under the terms of the GNU Lesser General Public | |
| 22 // License as published by the Free Software Foundation; either | |
| 23 // version 2.1 of the License, or (at your option) any later version. | |
| 24 // | |
| 25 // This library is distributed in the hope that it will be useful, | |
| 26 // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 27 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 28 // Lesser General Public License for more details. | |
| 29 // | |
| 30 // You should have received a copy of the GNU Lesser General Public | |
| 31 // License along with this library; if not, write to the Free Software | |
| 32 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 33 // | |
| 34 //////////////////////////////////////////////////////////////////////////////// | |
| 35 | |
| 36 #include <stddef.h> | |
| 37 #include <math.h> | |
| 38 #include "InterpolateCubic.h" | |
| 39 #include "STTypes.h" | |
| 40 | |
| 41 using namespace soundtouch; | |
| 42 | |
| 43 // cubic interpolation coefficients | |
| 44 static const float _coeffs[]= | |
| 45 { -0.5f, 1.0f, -0.5f, 0.0f, | |
| 46 1.5f, -2.5f, 0.0f, 1.0f, | |
| 47 -1.5f, 2.0f, 0.5f, 0.0f, | |
| 48 0.5f, -0.5f, 0.0f, 0.0f}; | |
| 49 | |
| 50 | |
| 51 InterpolateCubic::InterpolateCubic() | |
| 52 { | |
| 53 fract = 0; | |
| 54 } | |
| 55 | |
| 56 | |
| 57 void InterpolateCubic::resetRegisters() | |
| 58 { | |
| 59 fract = 0; | |
| 60 } | |
| 61 | |
| 62 | |
| 63 /// Transpose mono audio. Returns number of produced output samples, and | |
| 64 /// updates "srcSamples" to amount of consumed source samples | |
| 65 int InterpolateCubic::transposeMono(SAMPLETYPE *pdest, | |
| 66 const SAMPLETYPE *psrc, | |
| 67 int &srcSamples) | |
| 68 { | |
| 69 int i; | |
| 70 int srcSampleEnd = srcSamples - 4; | |
| 71 int srcCount = 0; | |
| 72 | |
| 73 i = 0; | |
| 74 while (srcCount < srcSampleEnd) | |
| 75 { | |
| 76 float out; | |
| 77 const float x3 = 1.0f; | |
| 78 const float x2 = (float)fract; // x | |
| 79 const float x1 = x2*x2; // x^2 | |
| 80 const float x0 = x1*x2; // x^3 | |
| 81 float y0, y1, y2, y3; | |
| 82 | |
| 83 assert(fract < 1.0); | |
| 84 | |
| 85 y0 = _coeffs[0] * x0 + _coeffs[1] * x1 + _coeffs[2] * x2 + _coeffs[3] * x3; | |
| 86 y1 = _coeffs[4] * x0 + _coeffs[5] * x1 + _coeffs[6] * x2 + _coeffs[7] * x3; | |
| 87 y2 = _coeffs[8] * x0 + _coeffs[9] * x1 + _coeffs[10] * x2 + _coeffs[11] * x3; | |
| 88 y3 = _coeffs[12] * x0 + _coeffs[13] * x1 + _coeffs[14] * x2 + _coeffs[15] * x3; | |
| 89 | |
| 90 out = y0 * psrc[0] + y1 * psrc[1] + y2 * psrc[2] + y3 * psrc[3]; | |
| 91 | |
| 92 pdest[i] = (SAMPLETYPE)out; | |
| 93 i ++; | |
| 94 | |
| 95 // update position fraction | |
| 96 fract += rate; | |
| 97 // update whole positions | |
| 98 int whole = (int)fract; | |
| 99 fract -= whole; | |
| 100 psrc += whole; | |
| 101 srcCount += whole; | |
| 102 } | |
| 103 srcSamples = srcCount; | |
| 104 return i; | |
| 105 } | |
| 106 | |
| 107 | |
| 108 /// Transpose stereo audio. Returns number of produced output samples, and | |
| 109 /// updates "srcSamples" to amount of consumed source samples | |
| 110 int InterpolateCubic::transposeStereo(SAMPLETYPE *pdest, | |
| 111 const SAMPLETYPE *psrc, | |
| 112 int &srcSamples) | |
| 113 { | |
| 114 int i; | |
| 115 int srcSampleEnd = srcSamples - 4; | |
| 116 int srcCount = 0; | |
| 117 | |
| 118 i = 0; | |
| 119 while (srcCount < srcSampleEnd) | |
| 120 { | |
| 121 const float x3 = 1.0f; | |
| 122 const float x2 = (float)fract; // x | |
| 123 const float x1 = x2*x2; // x^2 | |
| 124 const float x0 = x1*x2; // x^3 | |
| 125 float y0, y1, y2, y3; | |
| 126 float out0, out1; | |
| 127 | |
| 128 assert(fract < 1.0); | |
| 129 | |
| 130 y0 = _coeffs[0] * x0 + _coeffs[1] * x1 + _coeffs[2] * x2 + _coeffs[3] * x3; | |
| 131 y1 = _coeffs[4] * x0 + _coeffs[5] * x1 + _coeffs[6] * x2 + _coeffs[7] * x3; | |
| 132 y2 = _coeffs[8] * x0 + _coeffs[9] * x1 + _coeffs[10] * x2 + _coeffs[11] * x3; | |
| 133 y3 = _coeffs[12] * x0 + _coeffs[13] * x1 + _coeffs[14] * x2 + _coeffs[15] * x3; | |
| 134 | |
| 135 out0 = y0 * psrc[0] + y1 * psrc[2] + y2 * psrc[4] + y3 * psrc[6]; | |
| 136 out1 = y0 * psrc[1] + y1 * psrc[3] + y2 * psrc[5] + y3 * psrc[7]; | |
| 137 | |
| 138 pdest[2*i] = (SAMPLETYPE)out0; | |
| 139 pdest[2*i+1] = (SAMPLETYPE)out1; | |
| 140 i ++; | |
| 141 | |
| 142 // update position fraction | |
| 143 fract += rate; | |
| 144 // update whole positions | |
| 145 int whole = (int)fract; | |
| 146 fract -= whole; | |
| 147 psrc += 2*whole; | |
| 148 srcCount += whole; | |
| 149 } | |
| 150 srcSamples = srcCount; | |
| 151 return i; | |
| 152 } | |
| 153 | |
| 154 | |
| 155 /// Transpose multi-channel audio. Returns number of produced output samples, and | |
| 156 /// updates "srcSamples" to amount of consumed source samples | |
| 157 int InterpolateCubic::transposeMulti(SAMPLETYPE *pdest, | |
| 158 const SAMPLETYPE *psrc, | |
| 159 int &srcSamples) | |
| 160 { | |
| 161 int i; | |
| 162 int srcSampleEnd = srcSamples - 4; | |
| 163 int srcCount = 0; | |
| 164 | |
| 165 i = 0; | |
| 166 while (srcCount < srcSampleEnd) | |
| 167 { | |
| 168 const float x3 = 1.0f; | |
| 169 const float x2 = (float)fract; // x | |
| 170 const float x1 = x2*x2; // x^2 | |
| 171 const float x0 = x1*x2; // x^3 | |
| 172 float y0, y1, y2, y3; | |
| 173 | |
| 174 assert(fract < 1.0); | |
| 175 | |
| 176 y0 = _coeffs[0] * x0 + _coeffs[1] * x1 + _coeffs[2] * x2 + _coeffs[3] * x3; | |
| 177 y1 = _coeffs[4] * x0 + _coeffs[5] * x1 + _coeffs[6] * x2 + _coeffs[7] * x3; | |
| 178 y2 = _coeffs[8] * x0 + _coeffs[9] * x1 + _coeffs[10] * x2 + _coeffs[11] * x3; | |
| 179 y3 = _coeffs[12] * x0 + _coeffs[13] * x1 + _coeffs[14] * x2 + _coeffs[15] * x3; | |
| 180 | |
| 181 for (int c = 0; c < numChannels; c ++) | |
| 182 { | |
| 183 float out; | |
| 184 out = y0 * psrc[c] + y1 * psrc[c + numChannels] + y2 * psrc[c + 2 * numChannels] + y3 * psrc[c + 3 * numChannels]; | |
| 185 pdest[0] = (SAMPLETYPE)out; | |
| 186 pdest ++; | |
| 187 } | |
| 188 i ++; | |
| 189 | |
| 190 // update position fraction | |
| 191 fract += rate; | |
| 192 // update whole positions | |
| 193 int whole = (int)fract; | |
| 194 fract -= whole; | |
| 195 psrc += numChannels*whole; | |
| 196 srcCount += whole; | |
| 197 } | |
| 198 srcSamples = srcCount; | |
| 199 return i; | |
| 200 } |
