annotate src/vamp-hostsdk/PluginInputDomainAdapter.cpp @ 233:521734d2b498 distinct-libraries

* Flatten directory tree a bit, update doxygen
author cannam
date Fri, 07 Nov 2008 15:28:33 +0000
parents
children 4454843ff384
rev   line source
cannam@233 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
cannam@233 2
cannam@233 3 /*
cannam@233 4 Vamp
cannam@233 5
cannam@233 6 An API for audio analysis and feature extraction plugins.
cannam@233 7
cannam@233 8 Centre for Digital Music, Queen Mary, University of London.
cannam@233 9 Copyright 2006-2007 Chris Cannam and QMUL.
cannam@233 10
cannam@233 11 This file is based in part on Don Cross's public domain FFT
cannam@233 12 implementation.
cannam@233 13
cannam@233 14 Permission is hereby granted, free of charge, to any person
cannam@233 15 obtaining a copy of this software and associated documentation
cannam@233 16 files (the "Software"), to deal in the Software without
cannam@233 17 restriction, including without limitation the rights to use, copy,
cannam@233 18 modify, merge, publish, distribute, sublicense, and/or sell copies
cannam@233 19 of the Software, and to permit persons to whom the Software is
cannam@233 20 furnished to do so, subject to the following conditions:
cannam@233 21
cannam@233 22 The above copyright notice and this permission notice shall be
cannam@233 23 included in all copies or substantial portions of the Software.
cannam@233 24
cannam@233 25 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
cannam@233 26 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
cannam@233 27 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
cannam@233 28 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
cannam@233 29 ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
cannam@233 30 CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
cannam@233 31 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
cannam@233 32
cannam@233 33 Except as contained in this notice, the names of the Centre for
cannam@233 34 Digital Music; Queen Mary, University of London; and Chris Cannam
cannam@233 35 shall not be used in advertising or otherwise to promote the sale,
cannam@233 36 use or other dealings in this Software without prior written
cannam@233 37 authorization.
cannam@233 38 */
cannam@233 39
cannam@233 40 #include <vamp-hostsdk/PluginInputDomainAdapter.h>
cannam@233 41
cannam@233 42 #include <cmath>
cannam@233 43
cannam@233 44
cannam@233 45 /**
cannam@233 46 * If you want to compile using FFTW instead of the built-in FFT
cannam@233 47 * implementation for the PluginInputDomainAdapter, define HAVE_FFTW3
cannam@233 48 * in the Makefile.
cannam@233 49 *
cannam@233 50 * Be aware that FFTW is licensed under the GPL -- unlike this SDK,
cannam@233 51 * which is provided under a more liberal BSD license in order to
cannam@233 52 * permit use in closed source applications. The use of FFTW would
cannam@233 53 * mean that your code would need to be licensed under the GPL as
cannam@233 54 * well. Do not define this symbol unless you understand and accept
cannam@233 55 * the implications of this.
cannam@233 56 *
cannam@233 57 * Parties such as Linux distribution packagers who redistribute this
cannam@233 58 * SDK for use in other programs should _not_ define this symbol, as
cannam@233 59 * it would change the effective licensing terms under which the SDK
cannam@233 60 * was available to third party developers.
cannam@233 61 *
cannam@233 62 * The default is not to use FFTW, and to use the built-in FFT instead.
cannam@233 63 *
cannam@233 64 * Note: The FFTW code uses FFTW_MEASURE, and so will perform badly on
cannam@233 65 * its first invocation unless the host has saved and restored FFTW
cannam@233 66 * wisdom (see the FFTW documentation).
cannam@233 67 */
cannam@233 68 #ifdef HAVE_FFTW3
cannam@233 69 #include <fftw3.h>
cannam@233 70 #endif
cannam@233 71
cannam@233 72
cannam@233 73 namespace Vamp {
cannam@233 74
cannam@233 75 namespace HostExt {
cannam@233 76
cannam@233 77 class PluginInputDomainAdapter::Impl
cannam@233 78 {
cannam@233 79 public:
cannam@233 80 Impl(Plugin *plugin, float inputSampleRate);
cannam@233 81 ~Impl();
cannam@233 82
cannam@233 83 bool initialise(size_t channels, size_t stepSize, size_t blockSize);
cannam@233 84
cannam@233 85 size_t getPreferredStepSize() const;
cannam@233 86 size_t getPreferredBlockSize() const;
cannam@233 87
cannam@233 88 FeatureSet process(const float *const *inputBuffers, RealTime timestamp);
cannam@233 89
cannam@233 90 RealTime getTimestampAdjustment() const;
cannam@233 91
cannam@233 92 protected:
cannam@233 93 Plugin *m_plugin;
cannam@233 94 float m_inputSampleRate;
cannam@233 95 int m_channels;
cannam@233 96 int m_blockSize;
cannam@233 97 float **m_freqbuf;
cannam@233 98
cannam@233 99 double *m_ri;
cannam@233 100 double *m_window;
cannam@233 101
cannam@233 102 #ifdef HAVE_FFTW3
cannam@233 103 fftw_plan m_plan;
cannam@233 104 fftw_complex *m_cbuf;
cannam@233 105 #else
cannam@233 106 double *m_ro;
cannam@233 107 double *m_io;
cannam@233 108 void fft(unsigned int n, bool inverse,
cannam@233 109 double *ri, double *ii, double *ro, double *io);
cannam@233 110 #endif
cannam@233 111
cannam@233 112 size_t makeBlockSizeAcceptable(size_t) const;
cannam@233 113 };
cannam@233 114
cannam@233 115 PluginInputDomainAdapter::PluginInputDomainAdapter(Plugin *plugin) :
cannam@233 116 PluginWrapper(plugin)
cannam@233 117 {
cannam@233 118 m_impl = new Impl(plugin, m_inputSampleRate);
cannam@233 119 }
cannam@233 120
cannam@233 121 PluginInputDomainAdapter::~PluginInputDomainAdapter()
cannam@233 122 {
cannam@233 123 delete m_impl;
cannam@233 124 }
cannam@233 125
cannam@233 126 bool
cannam@233 127 PluginInputDomainAdapter::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@233 128 {
cannam@233 129 return m_impl->initialise(channels, stepSize, blockSize);
cannam@233 130 }
cannam@233 131
cannam@233 132 Plugin::InputDomain
cannam@233 133 PluginInputDomainAdapter::getInputDomain() const
cannam@233 134 {
cannam@233 135 return TimeDomain;
cannam@233 136 }
cannam@233 137
cannam@233 138 size_t
cannam@233 139 PluginInputDomainAdapter::getPreferredStepSize() const
cannam@233 140 {
cannam@233 141 return m_impl->getPreferredStepSize();
cannam@233 142 }
cannam@233 143
cannam@233 144 size_t
cannam@233 145 PluginInputDomainAdapter::getPreferredBlockSize() const
cannam@233 146 {
cannam@233 147 return m_impl->getPreferredBlockSize();
cannam@233 148 }
cannam@233 149
cannam@233 150 Plugin::FeatureSet
cannam@233 151 PluginInputDomainAdapter::process(const float *const *inputBuffers, RealTime timestamp)
cannam@233 152 {
cannam@233 153 return m_impl->process(inputBuffers, timestamp);
cannam@233 154 }
cannam@233 155
cannam@233 156 RealTime
cannam@233 157 PluginInputDomainAdapter::getTimestampAdjustment() const
cannam@233 158 {
cannam@233 159 return m_impl->getTimestampAdjustment();
cannam@233 160 }
cannam@233 161
cannam@233 162
cannam@233 163 PluginInputDomainAdapter::Impl::Impl(Plugin *plugin, float inputSampleRate) :
cannam@233 164 m_plugin(plugin),
cannam@233 165 m_inputSampleRate(inputSampleRate),
cannam@233 166 m_channels(0),
cannam@233 167 m_blockSize(0),
cannam@233 168 m_freqbuf(0),
cannam@233 169 m_ri(0),
cannam@233 170 m_window(0),
cannam@233 171 #ifdef HAVE_FFTW3
cannam@233 172 m_plan(0),
cannam@233 173 m_cbuf(0)
cannam@233 174 #else
cannam@233 175 m_ro(0),
cannam@233 176 m_io(0)
cannam@233 177 #endif
cannam@233 178 {
cannam@233 179 }
cannam@233 180
cannam@233 181 PluginInputDomainAdapter::Impl::~Impl()
cannam@233 182 {
cannam@233 183 // the adapter will delete the plugin
cannam@233 184
cannam@233 185 if (m_channels > 0) {
cannam@233 186 for (int c = 0; c < m_channels; ++c) {
cannam@233 187 delete[] m_freqbuf[c];
cannam@233 188 }
cannam@233 189 delete[] m_freqbuf;
cannam@233 190 #ifdef HAVE_FFTW3
cannam@233 191 if (m_plan) {
cannam@233 192 fftw_destroy_plan(m_plan);
cannam@233 193 fftw_free(m_ri);
cannam@233 194 fftw_free(m_cbuf);
cannam@233 195 m_plan = 0;
cannam@233 196 }
cannam@233 197 #else
cannam@233 198 delete[] m_ri;
cannam@233 199 delete[] m_ro;
cannam@233 200 delete[] m_io;
cannam@233 201 #endif
cannam@233 202 delete[] m_window;
cannam@233 203 }
cannam@233 204 }
cannam@233 205
cannam@233 206 // for some visual studii apparently
cannam@233 207 #ifndef M_PI
cannam@233 208 #define M_PI 3.14159265358979232846
cannam@233 209 #endif
cannam@233 210
cannam@233 211 bool
cannam@233 212 PluginInputDomainAdapter::Impl::initialise(size_t channels, size_t stepSize, size_t blockSize)
cannam@233 213 {
cannam@233 214 if (m_plugin->getInputDomain() == TimeDomain) {
cannam@233 215
cannam@233 216 m_blockSize = int(blockSize);
cannam@233 217 m_channels = int(channels);
cannam@233 218
cannam@233 219 return m_plugin->initialise(channels, stepSize, blockSize);
cannam@233 220 }
cannam@233 221
cannam@233 222 if (blockSize < 2) {
cannam@233 223 std::cerr << "ERROR: Vamp::HostExt::PluginInputDomainAdapter::Impl::initialise: blocksize < 2 not supported" << std::endl;
cannam@233 224 return false;
cannam@233 225 }
cannam@233 226
cannam@233 227 if (blockSize & (blockSize-1)) {
cannam@233 228 std::cerr << "ERROR: Vamp::HostExt::PluginInputDomainAdapter::Impl::initialise: non-power-of-two\nblocksize " << blockSize << " not supported" << std::endl;
cannam@233 229 return false;
cannam@233 230 }
cannam@233 231
cannam@233 232 if (m_channels > 0) {
cannam@233 233 for (int c = 0; c < m_channels; ++c) {
cannam@233 234 delete[] m_freqbuf[c];
cannam@233 235 }
cannam@233 236 delete[] m_freqbuf;
cannam@233 237 #ifdef HAVE_FFTW3
cannam@233 238 if (m_plan) {
cannam@233 239 fftw_destroy_plan(m_plan);
cannam@233 240 fftw_free(m_ri);
cannam@233 241 fftw_free(m_cbuf);
cannam@233 242 m_plan = 0;
cannam@233 243 }
cannam@233 244 #else
cannam@233 245 delete[] m_ri;
cannam@233 246 delete[] m_ro;
cannam@233 247 delete[] m_io;
cannam@233 248 #endif
cannam@233 249 delete[] m_window;
cannam@233 250 }
cannam@233 251
cannam@233 252 m_blockSize = int(blockSize);
cannam@233 253 m_channels = int(channels);
cannam@233 254
cannam@233 255 m_freqbuf = new float *[m_channels];
cannam@233 256 for (int c = 0; c < m_channels; ++c) {
cannam@233 257 m_freqbuf[c] = new float[m_blockSize + 2];
cannam@233 258 }
cannam@233 259 m_window = new double[m_blockSize];
cannam@233 260
cannam@233 261 for (int i = 0; i < m_blockSize; ++i) {
cannam@233 262 // Hanning window
cannam@233 263 m_window[i] = (0.50 - 0.50 * cos((2.0 * M_PI * i) / m_blockSize));
cannam@233 264 }
cannam@233 265
cannam@233 266 #ifdef HAVE_FFTW3
cannam@233 267 m_ri = (double *)fftw_malloc(blockSize * sizeof(double));
cannam@233 268 m_cbuf = (fftw_complex *)fftw_malloc((blockSize/2 + 1) * sizeof(fftw_complex));
cannam@233 269 m_plan = fftw_plan_dft_r2c_1d(blockSize, m_ri, m_cbuf, FFTW_MEASURE);
cannam@233 270 #else
cannam@233 271 m_ri = new double[m_blockSize];
cannam@233 272 m_ro = new double[m_blockSize];
cannam@233 273 m_io = new double[m_blockSize];
cannam@233 274 #endif
cannam@233 275
cannam@233 276 return m_plugin->initialise(channels, stepSize, blockSize);
cannam@233 277 }
cannam@233 278
cannam@233 279 size_t
cannam@233 280 PluginInputDomainAdapter::Impl::getPreferredStepSize() const
cannam@233 281 {
cannam@233 282 size_t step = m_plugin->getPreferredStepSize();
cannam@233 283
cannam@233 284 if (step == 0 && (m_plugin->getInputDomain() == FrequencyDomain)) {
cannam@233 285 step = getPreferredBlockSize() / 2;
cannam@233 286 }
cannam@233 287
cannam@233 288 return step;
cannam@233 289 }
cannam@233 290
cannam@233 291 size_t
cannam@233 292 PluginInputDomainAdapter::Impl::getPreferredBlockSize() const
cannam@233 293 {
cannam@233 294 size_t block = m_plugin->getPreferredBlockSize();
cannam@233 295
cannam@233 296 if (m_plugin->getInputDomain() == FrequencyDomain) {
cannam@233 297 if (block == 0) {
cannam@233 298 block = 1024;
cannam@233 299 } else {
cannam@233 300 block = makeBlockSizeAcceptable(block);
cannam@233 301 }
cannam@233 302 }
cannam@233 303
cannam@233 304 return block;
cannam@233 305 }
cannam@233 306
cannam@233 307 size_t
cannam@233 308 PluginInputDomainAdapter::Impl::makeBlockSizeAcceptable(size_t blockSize) const
cannam@233 309 {
cannam@233 310 if (blockSize < 2) {
cannam@233 311
cannam@233 312 std::cerr << "WARNING: Vamp::HostExt::PluginInputDomainAdapter::Impl::initialise: blocksize < 2 not" << std::endl
cannam@233 313 << "supported, increasing from " << blockSize << " to 2" << std::endl;
cannam@233 314 blockSize = 2;
cannam@233 315
cannam@233 316 } else if (blockSize & (blockSize-1)) {
cannam@233 317
cannam@233 318 #ifdef HAVE_FFTW3
cannam@233 319 // not an issue with FFTW
cannam@233 320 #else
cannam@233 321
cannam@233 322 // not a power of two, can't handle that with our built-in FFT
cannam@233 323 // implementation
cannam@233 324
cannam@233 325 size_t nearest = blockSize;
cannam@233 326 size_t power = 0;
cannam@233 327 while (nearest > 1) {
cannam@233 328 nearest >>= 1;
cannam@233 329 ++power;
cannam@233 330 }
cannam@233 331 nearest = 1;
cannam@233 332 while (power) {
cannam@233 333 nearest <<= 1;
cannam@233 334 --power;
cannam@233 335 }
cannam@233 336
cannam@233 337 if (blockSize - nearest > (nearest*2) - blockSize) {
cannam@233 338 nearest = nearest*2;
cannam@233 339 }
cannam@233 340
cannam@233 341 std::cerr << "WARNING: Vamp::HostExt::PluginInputDomainAdapter::Impl::initialise: non-power-of-two\nblocksize " << blockSize << " not supported, using blocksize " << nearest << " instead" << std::endl;
cannam@233 342 blockSize = nearest;
cannam@233 343
cannam@233 344 #endif
cannam@233 345 }
cannam@233 346
cannam@233 347 return blockSize;
cannam@233 348 }
cannam@233 349
cannam@233 350 RealTime
cannam@233 351 PluginInputDomainAdapter::Impl::getTimestampAdjustment() const
cannam@233 352 {
cannam@233 353 if (m_plugin->getInputDomain() == TimeDomain) {
cannam@233 354 return RealTime::zeroTime;
cannam@233 355 } else {
cannam@233 356 return RealTime::frame2RealTime
cannam@233 357 (m_blockSize/2, int(m_inputSampleRate + 0.5));
cannam@233 358 }
cannam@233 359 }
cannam@233 360
cannam@233 361 Plugin::FeatureSet
cannam@233 362 PluginInputDomainAdapter::Impl::process(const float *const *inputBuffers,
cannam@233 363 RealTime timestamp)
cannam@233 364 {
cannam@233 365 if (m_plugin->getInputDomain() == TimeDomain) {
cannam@233 366 return m_plugin->process(inputBuffers, timestamp);
cannam@233 367 }
cannam@233 368
cannam@233 369 // The timestamp supplied should be (according to the Vamp::Plugin
cannam@233 370 // spec) the time of the start of the time-domain input block.
cannam@233 371 // However, we want to pass to the plugin an FFT output calculated
cannam@233 372 // from the block of samples _centred_ on that timestamp.
cannam@233 373 //
cannam@233 374 // We have two options:
cannam@233 375 //
cannam@233 376 // 1. Buffer the input, calculating the fft of the values at the
cannam@233 377 // passed-in block minus blockSize/2 rather than starting at the
cannam@233 378 // passed-in block. So each time we call process on the plugin,
cannam@233 379 // we are passing in the same timestamp as was passed to our own
cannam@233 380 // process plugin, but not (the frequency domain representation
cannam@233 381 // of) the same set of samples. Advantages: avoids confusion in
cannam@233 382 // the host by ensuring the returned values have timestamps
cannam@233 383 // comparable with that passed in to this function (in fact this
cannam@233 384 // is pretty much essential for one-value-per-block outputs);
cannam@233 385 // consistent with hosts such as SV that deal with the
cannam@233 386 // frequency-domain transform themselves. Disadvantages: means
cannam@233 387 // making the not necessarily correct assumption that the samples
cannam@233 388 // preceding the first official block are all zero (or some other
cannam@233 389 // known value).
cannam@233 390 //
cannam@233 391 // 2. Increase the passed-in timestamps by half the blocksize. So
cannam@233 392 // when we call process, we are passing in the frequency domain
cannam@233 393 // representation of the same set of samples as passed to us, but
cannam@233 394 // with a different timestamp. Advantages: simplicity; avoids
cannam@233 395 // iffy assumption mentioned above. Disadvantages: inconsistency
cannam@233 396 // with SV in cases where stepSize != blockSize/2; potential
cannam@233 397 // confusion arising from returned timestamps being calculated
cannam@233 398 // from the adjusted input timestamps rather than the original
cannam@233 399 // ones (and inaccuracy where the returned timestamp is implied,
cannam@233 400 // as in one-value-per-block).
cannam@233 401 //
cannam@233 402 // Neither way is ideal, but I don't think either is strictly
cannam@233 403 // incorrect either. I think this is just a case where the same
cannam@233 404 // plugin can legitimately produce differing results from the same
cannam@233 405 // input data, depending on how that data is packaged.
cannam@233 406 //
cannam@233 407 // We'll go for option 2, adjusting the timestamps. Note in
cannam@233 408 // particular that this means some results can differ from those
cannam@233 409 // produced by SV.
cannam@233 410
cannam@233 411 // std::cerr << "PluginInputDomainAdapter: sampleRate " << m_inputSampleRate << ", blocksize " << m_blockSize << ", adjusting time from " << timestamp;
cannam@233 412
cannam@233 413 timestamp = timestamp + getTimestampAdjustment();
cannam@233 414
cannam@233 415 // std::cerr << " to " << timestamp << std::endl;
cannam@233 416
cannam@233 417 for (int c = 0; c < m_channels; ++c) {
cannam@233 418
cannam@233 419 for (int i = 0; i < m_blockSize; ++i) {
cannam@233 420 m_ri[i] = double(inputBuffers[c][i]) * m_window[i];
cannam@233 421 }
cannam@233 422
cannam@233 423 for (int i = 0; i < m_blockSize/2; ++i) {
cannam@233 424 // FFT shift
cannam@233 425 double value = m_ri[i];
cannam@233 426 m_ri[i] = m_ri[i + m_blockSize/2];
cannam@233 427 m_ri[i + m_blockSize/2] = value;
cannam@233 428 }
cannam@233 429
cannam@233 430 #ifdef HAVE_FFTW3
cannam@233 431
cannam@233 432 fftw_execute(m_plan);
cannam@233 433
cannam@233 434 for (int i = 0; i <= m_blockSize/2; ++i) {
cannam@233 435 m_freqbuf[c][i * 2] = float(m_cbuf[i][0]);
cannam@233 436 m_freqbuf[c][i * 2 + 1] = float(m_cbuf[i][1]);
cannam@233 437 }
cannam@233 438
cannam@233 439 #else
cannam@233 440
cannam@233 441 fft(m_blockSize, false, m_ri, 0, m_ro, m_io);
cannam@233 442
cannam@233 443 for (int i = 0; i <= m_blockSize/2; ++i) {
cannam@233 444 m_freqbuf[c][i * 2] = float(m_ro[i]);
cannam@233 445 m_freqbuf[c][i * 2 + 1] = float(m_io[i]);
cannam@233 446 }
cannam@233 447
cannam@233 448 #endif
cannam@233 449 }
cannam@233 450
cannam@233 451 return m_plugin->process(m_freqbuf, timestamp);
cannam@233 452 }
cannam@233 453
cannam@233 454 #ifndef HAVE_FFTW3
cannam@233 455
cannam@233 456 void
cannam@233 457 PluginInputDomainAdapter::Impl::fft(unsigned int n, bool inverse,
cannam@233 458 double *ri, double *ii, double *ro, double *io)
cannam@233 459 {
cannam@233 460 if (!ri || !ro || !io) return;
cannam@233 461
cannam@233 462 unsigned int bits;
cannam@233 463 unsigned int i, j, k, m;
cannam@233 464 unsigned int blockSize, blockEnd;
cannam@233 465
cannam@233 466 double tr, ti;
cannam@233 467
cannam@233 468 if (n < 2) return;
cannam@233 469 if (n & (n-1)) return;
cannam@233 470
cannam@233 471 double angle = 2.0 * M_PI;
cannam@233 472 if (inverse) angle = -angle;
cannam@233 473
cannam@233 474 for (i = 0; ; ++i) {
cannam@233 475 if (n & (1 << i)) {
cannam@233 476 bits = i;
cannam@233 477 break;
cannam@233 478 }
cannam@233 479 }
cannam@233 480
cannam@233 481 static unsigned int tableSize = 0;
cannam@233 482 static int *table = 0;
cannam@233 483
cannam@233 484 if (tableSize != n) {
cannam@233 485
cannam@233 486 delete[] table;
cannam@233 487
cannam@233 488 table = new int[n];
cannam@233 489
cannam@233 490 for (i = 0; i < n; ++i) {
cannam@233 491
cannam@233 492 m = i;
cannam@233 493
cannam@233 494 for (j = k = 0; j < bits; ++j) {
cannam@233 495 k = (k << 1) | (m & 1);
cannam@233 496 m >>= 1;
cannam@233 497 }
cannam@233 498
cannam@233 499 table[i] = k;
cannam@233 500 }
cannam@233 501
cannam@233 502 tableSize = n;
cannam@233 503 }
cannam@233 504
cannam@233 505 if (ii) {
cannam@233 506 for (i = 0; i < n; ++i) {
cannam@233 507 ro[table[i]] = ri[i];
cannam@233 508 io[table[i]] = ii[i];
cannam@233 509 }
cannam@233 510 } else {
cannam@233 511 for (i = 0; i < n; ++i) {
cannam@233 512 ro[table[i]] = ri[i];
cannam@233 513 io[table[i]] = 0.0;
cannam@233 514 }
cannam@233 515 }
cannam@233 516
cannam@233 517 blockEnd = 1;
cannam@233 518
cannam@233 519 for (blockSize = 2; blockSize <= n; blockSize <<= 1) {
cannam@233 520
cannam@233 521 double delta = angle / (double)blockSize;
cannam@233 522 double sm2 = -sin(-2 * delta);
cannam@233 523 double sm1 = -sin(-delta);
cannam@233 524 double cm2 = cos(-2 * delta);
cannam@233 525 double cm1 = cos(-delta);
cannam@233 526 double w = 2 * cm1;
cannam@233 527 double ar[3], ai[3];
cannam@233 528
cannam@233 529 for (i = 0; i < n; i += blockSize) {
cannam@233 530
cannam@233 531 ar[2] = cm2;
cannam@233 532 ar[1] = cm1;
cannam@233 533
cannam@233 534 ai[2] = sm2;
cannam@233 535 ai[1] = sm1;
cannam@233 536
cannam@233 537 for (j = i, m = 0; m < blockEnd; j++, m++) {
cannam@233 538
cannam@233 539 ar[0] = w * ar[1] - ar[2];
cannam@233 540 ar[2] = ar[1];
cannam@233 541 ar[1] = ar[0];
cannam@233 542
cannam@233 543 ai[0] = w * ai[1] - ai[2];
cannam@233 544 ai[2] = ai[1];
cannam@233 545 ai[1] = ai[0];
cannam@233 546
cannam@233 547 k = j + blockEnd;
cannam@233 548 tr = ar[0] * ro[k] - ai[0] * io[k];
cannam@233 549 ti = ar[0] * io[k] + ai[0] * ro[k];
cannam@233 550
cannam@233 551 ro[k] = ro[j] - tr;
cannam@233 552 io[k] = io[j] - ti;
cannam@233 553
cannam@233 554 ro[j] += tr;
cannam@233 555 io[j] += ti;
cannam@233 556 }
cannam@233 557 }
cannam@233 558
cannam@233 559 blockEnd = blockSize;
cannam@233 560 }
cannam@233 561
cannam@233 562 if (inverse) {
cannam@233 563
cannam@233 564 double denom = (double)n;
cannam@233 565
cannam@233 566 for (i = 0; i < n; i++) {
cannam@233 567 ro[i] /= denom;
cannam@233 568 io[i] /= denom;
cannam@233 569 }
cannam@233 570 }
cannam@233 571 }
cannam@233 572
cannam@233 573 #endif
cannam@233 574
cannam@233 575 }
cannam@233 576
cannam@233 577 }
cannam@233 578