annotate data/model/FFTModel.cpp @ 1184:e5a1d815f331 3.0-integration

Merge from the default branch
author Chris Cannam
date Thu, 21 Apr 2016 15:29:30 +0100
parents 444d133b5ab7
children 12a8daa89970
rev   line source
Chris@152 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
Chris@152 2
Chris@152 3 /*
Chris@152 4 Sonic Visualiser
Chris@152 5 An audio file viewer and annotation editor.
Chris@152 6 Centre for Digital Music, Queen Mary, University of London.
Chris@152 7 This file copyright 2006 Chris Cannam.
Chris@152 8
Chris@152 9 This program is free software; you can redistribute it and/or
Chris@152 10 modify it under the terms of the GNU General Public License as
Chris@152 11 published by the Free Software Foundation; either version 2 of the
Chris@152 12 License, or (at your option) any later version. See the file
Chris@152 13 COPYING included with this distribution for more information.
Chris@152 14 */
Chris@152 15
Chris@152 16 #include "FFTModel.h"
Chris@152 17 #include "DenseTimeValueModel.h"
Chris@152 18
Chris@183 19 #include "base/Profiler.h"
Chris@275 20 #include "base/Pitch.h"
Chris@183 21
Chris@402 22 #include <algorithm>
Chris@402 23
Chris@152 24 #include <cassert>
Chris@1090 25 #include <deque>
Chris@152 26
Chris@608 27 #ifndef __GNUC__
Chris@608 28 #include <alloca.h>
Chris@608 29 #endif
Chris@608 30
Chris@1090 31 using namespace std;
Chris@1090 32
Chris@152 33 FFTModel::FFTModel(const DenseTimeValueModel *model,
Chris@152 34 int channel,
Chris@152 35 WindowType windowType,
Chris@929 36 int windowSize,
Chris@929 37 int windowIncrement,
Chris@1090 38 int fftSize) :
Chris@1090 39 m_model(model),
Chris@1090 40 m_channel(channel),
Chris@1090 41 m_windowType(windowType),
Chris@1090 42 m_windowSize(windowSize),
Chris@1090 43 m_windowIncrement(windowIncrement),
Chris@1090 44 m_fftSize(fftSize),
Chris@1091 45 m_windower(windowType, windowSize),
Chris@1093 46 m_fft(fftSize),
Chris@1093 47 m_cacheSize(3)
Chris@152 48 {
Chris@1091 49 if (m_windowSize > m_fftSize) {
Chris@1091 50 cerr << "ERROR: FFTModel::FFTModel: window size (" << m_windowSize
Chris@1091 51 << ") must be at least FFT size (" << m_fftSize << ")" << endl;
Chris@1091 52 throw invalid_argument("FFTModel window size must be at least FFT size");
Chris@1091 53 }
Chris@1133 54
Chris@1133 55 connect(model, SIGNAL(modelChanged()), this, SIGNAL(modelChanged()));
Chris@1133 56 connect(model, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)),
Chris@1133 57 this, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)));
Chris@152 58 }
Chris@152 59
Chris@152 60 FFTModel::~FFTModel()
Chris@152 61 {
Chris@152 62 }
Chris@152 63
Chris@360 64 void
Chris@360 65 FFTModel::sourceModelAboutToBeDeleted()
Chris@360 66 {
Chris@1090 67 if (m_model) {
Chris@1090 68 cerr << "FFTModel[" << this << "]::sourceModelAboutToBeDeleted(" << m_model << ")" << endl;
Chris@1090 69 m_model = 0;
Chris@360 70 }
Chris@360 71 }
Chris@360 72
Chris@1091 73 int
Chris@1091 74 FFTModel::getWidth() const
Chris@1091 75 {
Chris@1091 76 if (!m_model) return 0;
Chris@1091 77 return int((m_model->getEndFrame() - m_model->getStartFrame())
Chris@1091 78 / m_windowIncrement) + 1;
Chris@1091 79 }
Chris@1091 80
Chris@1091 81 int
Chris@1091 82 FFTModel::getHeight() const
Chris@1091 83 {
Chris@1091 84 return m_fftSize / 2 + 1;
Chris@1091 85 }
Chris@1091 86
Chris@152 87 QString
Chris@929 88 FFTModel::getBinName(int n) const
Chris@152 89 {
Chris@1040 90 sv_samplerate_t sr = getSampleRate();
Chris@152 91 if (!sr) return "";
Chris@204 92 QString name = tr("%1 Hz").arg((n * sr) / ((getHeight()-1) * 2));
Chris@152 93 return name;
Chris@152 94 }
Chris@152 95
Chris@1091 96 FFTModel::Column
Chris@1091 97 FFTModel::getColumn(int x) const
Chris@1091 98 {
Chris@1091 99 auto cplx = getFFTColumn(x);
Chris@1091 100 Column col;
Chris@1154 101 col.reserve(cplx.size());
Chris@1091 102 for (auto c: cplx) col.push_back(abs(c));
Chris@1154 103 return move(col);
Chris@1091 104 }
Chris@1091 105
Chris@1091 106 float
Chris@1091 107 FFTModel::getMagnitudeAt(int x, int y) const
Chris@1091 108 {
Chris@1093 109 if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f;
Chris@1093 110 auto col = getFFTColumn(x);
Chris@1093 111 return abs(col[y]);
Chris@1091 112 }
Chris@1091 113
Chris@1091 114 float
Chris@1091 115 FFTModel::getMaximumMagnitudeAt(int x) const
Chris@1091 116 {
Chris@1091 117 Column col(getColumn(x));
Chris@1092 118 float max = 0.f;
Chris@1154 119 int n = int(col.size());
Chris@1154 120 for (int i = 0; i < n; ++i) {
Chris@1092 121 if (col[i] > max) max = col[i];
Chris@1092 122 }
Chris@1092 123 return max;
Chris@1091 124 }
Chris@1091 125
Chris@1091 126 float
Chris@1091 127 FFTModel::getPhaseAt(int x, int y) const
Chris@1091 128 {
Chris@1093 129 if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f;
Chris@1091 130 return arg(getFFTColumn(x)[y]);
Chris@1091 131 }
Chris@1091 132
Chris@1091 133 void
Chris@1091 134 FFTModel::getValuesAt(int x, int y, float &re, float &im) const
Chris@1091 135 {
Chris@1091 136 auto col = getFFTColumn(x);
Chris@1091 137 re = col[y].real();
Chris@1091 138 im = col[y].imag();
Chris@1091 139 }
Chris@1091 140
Chris@1091 141 bool
Chris@1091 142 FFTModel::getMagnitudesAt(int x, float *values, int minbin, int count) const
Chris@1091 143 {
Chris@1091 144 if (count == 0) count = getHeight();
Chris@1091 145 auto col = getFFTColumn(x);
Chris@1091 146 for (int i = 0; i < count; ++i) {
Chris@1091 147 values[i] = abs(col[minbin + i]);
Chris@1091 148 }
Chris@1091 149 return true;
Chris@1091 150 }
Chris@1091 151
Chris@1136 152 float
Chris@1091 153 FFTModel::getNormalizedMagnitudesAt(int x, float *values, int minbin, int count) const
Chris@1091 154 {
Chris@1092 155 if (!getMagnitudesAt(x, values, minbin, count)) return false;
Chris@1092 156 if (count == 0) count = getHeight();
Chris@1092 157 float max = 0.f;
Chris@1092 158 for (int i = 0; i < count; ++i) {
Chris@1092 159 if (values[i] > max) max = values[i];
Chris@1092 160 }
Chris@1092 161 if (max > 0.f) {
Chris@1092 162 for (int i = 0; i < count; ++i) {
Chris@1092 163 values[i] /= max;
Chris@1092 164 }
Chris@1092 165 }
Chris@1136 166 return max;
Chris@1091 167 }
Chris@1091 168
Chris@1091 169 bool
Chris@1091 170 FFTModel::getPhasesAt(int x, float *values, int minbin, int count) const
Chris@1091 171 {
Chris@1091 172 if (count == 0) count = getHeight();
Chris@1091 173 auto col = getFFTColumn(x);
Chris@1091 174 for (int i = 0; i < count; ++i) {
Chris@1091 175 values[i] = arg(col[minbin + i]);
Chris@1091 176 }
Chris@1091 177 return true;
Chris@1091 178 }
Chris@1091 179
Chris@1091 180 bool
Chris@1091 181 FFTModel::getValuesAt(int x, float *reals, float *imags, int minbin, int count) const
Chris@1091 182 {
Chris@1091 183 if (count == 0) count = getHeight();
Chris@1091 184 auto col = getFFTColumn(x);
Chris@1091 185 for (int i = 0; i < count; ++i) {
Chris@1091 186 reals[i] = col[minbin + i].real();
Chris@1091 187 }
Chris@1091 188 for (int i = 0; i < count; ++i) {
Chris@1091 189 imags[i] = col[minbin + i].imag();
Chris@1091 190 }
Chris@1091 191 return true;
Chris@1091 192 }
Chris@1091 193
Chris@1091 194 vector<float>
Chris@1091 195 FFTModel::getSourceSamples(int column) const
Chris@1091 196 {
Chris@1094 197 // m_fftSize may be greater than m_windowSize, but not the reverse
Chris@1094 198
Chris@1094 199 // cerr << "getSourceSamples(" << column << ")" << endl;
Chris@1094 200
Chris@1091 201 auto range = getSourceSampleRange(column);
Chris@1094 202 auto data = getSourceData(range);
Chris@1094 203
Chris@1091 204 int off = (m_fftSize - m_windowSize) / 2;
Chris@1094 205
Chris@1094 206 if (off == 0) {
Chris@1094 207 return data;
Chris@1094 208 } else {
Chris@1094 209 vector<float> pad(off, 0.f);
Chris@1094 210 vector<float> padded;
Chris@1094 211 padded.reserve(m_fftSize);
Chris@1094 212 padded.insert(padded.end(), pad.begin(), pad.end());
Chris@1094 213 padded.insert(padded.end(), data.begin(), data.end());
Chris@1094 214 padded.insert(padded.end(), pad.begin(), pad.end());
Chris@1094 215 return padded;
Chris@1094 216 }
Chris@1094 217 }
Chris@1094 218
Chris@1094 219 vector<float>
Chris@1094 220 FFTModel::getSourceData(pair<sv_frame_t, sv_frame_t> range) const
Chris@1094 221 {
Chris@1094 222 // cerr << "getSourceData(" << range.first << "," << range.second
Chris@1094 223 // << "): saved range is (" << m_savedData.range.first
Chris@1094 224 // << "," << m_savedData.range.second << ")" << endl;
Chris@1094 225
Chris@1100 226 if (m_savedData.range == range) {
Chris@1100 227 return m_savedData.data;
Chris@1100 228 }
Chris@1094 229
Chris@1094 230 if (range.first < m_savedData.range.second &&
Chris@1094 231 range.first >= m_savedData.range.first &&
Chris@1094 232 range.second > m_savedData.range.second) {
Chris@1094 233
Chris@1100 234 sv_frame_t discard = range.first - m_savedData.range.first;
Chris@1100 235
Chris@1100 236 vector<float> acc(m_savedData.data.begin() + discard,
Chris@1100 237 m_savedData.data.end());
Chris@1094 238
Chris@1095 239 vector<float> rest =
Chris@1095 240 getSourceDataUncached({ m_savedData.range.second, range.second });
Chris@1100 241
Chris@1100 242 acc.insert(acc.end(), rest.begin(), rest.end());
Chris@1094 243
Chris@1095 244 m_savedData = { range, acc };
Chris@1095 245 return acc;
Chris@1095 246
Chris@1095 247 } else {
Chris@1095 248
Chris@1095 249 auto data = getSourceDataUncached(range);
Chris@1095 250 m_savedData = { range, data };
Chris@1095 251 return data;
Chris@1094 252 }
Chris@1095 253 }
Chris@1094 254
Chris@1095 255 vector<float>
Chris@1095 256 FFTModel::getSourceDataUncached(pair<sv_frame_t, sv_frame_t> range) const
Chris@1095 257 {
Chris@1091 258 decltype(range.first) pfx = 0;
Chris@1091 259 if (range.first < 0) {
Chris@1091 260 pfx = -range.first;
Chris@1091 261 range = { 0, range.second };
Chris@1091 262 }
Chris@1096 263
Chris@1096 264 auto data = m_model->getData(m_channel,
Chris@1096 265 range.first,
Chris@1096 266 range.second - range.first);
Chris@1096 267
Chris@1096 268 // don't return a partial frame
Chris@1096 269 data.resize(range.second - range.first, 0.f);
Chris@1096 270
Chris@1096 271 if (pfx > 0) {
Chris@1096 272 vector<float> pad(pfx, 0.f);
Chris@1096 273 data.insert(data.begin(), pad.begin(), pad.end());
Chris@1096 274 }
Chris@1096 275
Chris@1091 276 if (m_channel == -1) {
Chris@1091 277 int channels = m_model->getChannelCount();
Chris@1091 278 if (channels > 1) {
Chris@1096 279 int n = int(data.size());
Chris@1096 280 float factor = 1.f / float(channels);
Chris@1100 281 // use mean instead of sum for fft model input
Chris@1096 282 for (int i = 0; i < n; ++i) {
Chris@1096 283 data[i] *= factor;
Chris@1091 284 }
Chris@1091 285 }
Chris@1091 286 }
Chris@1094 287
Chris@1094 288 return data;
Chris@1091 289 }
Chris@1091 290
Chris@1091 291 vector<complex<float>>
Chris@1093 292 FFTModel::getFFTColumn(int n) const
Chris@1091 293 {
Chris@1093 294 for (auto &incache : m_cached) {
Chris@1093 295 if (incache.n == n) {
Chris@1093 296 return incache.col;
Chris@1093 297 }
Chris@1093 298 }
Chris@1093 299
Chris@1093 300 auto samples = getSourceSamples(n);
Chris@1100 301 m_windower.cut(samples.data());
Chris@1093 302 auto col = m_fft.process(samples);
Chris@1093 303
Chris@1093 304 SavedColumn sc { n, col };
Chris@1093 305 if (m_cached.size() >= m_cacheSize) {
Chris@1093 306 m_cached.pop_front();
Chris@1093 307 }
Chris@1093 308 m_cached.push_back(sc);
Chris@1093 309
Chris@1154 310 return move(col);
Chris@1091 311 }
Chris@1091 312
Chris@275 313 bool
Chris@1045 314 FFTModel::estimateStableFrequency(int x, int y, double &frequency)
Chris@275 315 {
Chris@275 316 if (!isOK()) return false;
Chris@275 317
Chris@1090 318 frequency = double(y * getSampleRate()) / m_fftSize;
Chris@275 319
Chris@275 320 if (x+1 >= getWidth()) return false;
Chris@275 321
Chris@275 322 // At frequency f, a phase shift of 2pi (one cycle) happens in 1/f sec.
Chris@275 323 // At hopsize h and sample rate sr, one hop happens in h/sr sec.
Chris@275 324 // At window size w, for bin b, f is b*sr/w.
Chris@275 325 // thus 2pi phase shift happens in w/(b*sr) sec.
Chris@275 326 // We need to know what phase shift we expect from h/sr sec.
Chris@275 327 // -> 2pi * ((h/sr) / (w/(b*sr)))
Chris@275 328 // = 2pi * ((h * b * sr) / (w * sr))
Chris@275 329 // = 2pi * (h * b) / w.
Chris@275 330
Chris@1038 331 double oldPhase = getPhaseAt(x, y);
Chris@1038 332 double newPhase = getPhaseAt(x+1, y);
Chris@275 333
Chris@929 334 int incr = getResolution();
Chris@275 335
Chris@1090 336 double expectedPhase = oldPhase + (2.0 * M_PI * y * incr) / m_fftSize;
Chris@275 337
Chris@1038 338 double phaseError = princarg(newPhase - expectedPhase);
Chris@275 339
Chris@275 340 // The new frequency estimate based on the phase error resulting
Chris@275 341 // from assuming the "native" frequency of this bin
Chris@275 342
Chris@275 343 frequency =
Chris@1090 344 (getSampleRate() * (expectedPhase + phaseError - oldPhase)) /
Chris@1045 345 (2.0 * M_PI * incr);
Chris@275 346
Chris@275 347 return true;
Chris@275 348 }
Chris@275 349
Chris@275 350 FFTModel::PeakLocationSet
Chris@929 351 FFTModel::getPeaks(PeakPickType type, int x, int ymin, int ymax)
Chris@275 352 {
Chris@551 353 Profiler profiler("FFTModel::getPeaks");
Chris@551 354
Chris@275 355 FFTModel::PeakLocationSet peaks;
Chris@275 356 if (!isOK()) return peaks;
Chris@275 357
Chris@275 358 if (ymax == 0 || ymax > getHeight() - 1) {
Chris@275 359 ymax = getHeight() - 1;
Chris@275 360 }
Chris@275 361
Chris@275 362 if (type == AllPeaks) {
Chris@551 363 int minbin = ymin;
Chris@551 364 if (minbin > 0) minbin = minbin - 1;
Chris@551 365 int maxbin = ymax;
Chris@551 366 if (maxbin < getHeight() - 1) maxbin = maxbin + 1;
Chris@551 367 const int n = maxbin - minbin + 1;
Chris@608 368 #ifdef __GNUC__
Chris@551 369 float values[n];
Chris@608 370 #else
Chris@608 371 float *values = (float *)alloca(n * sizeof(float));
Chris@608 372 #endif
Chris@551 373 getMagnitudesAt(x, values, minbin, maxbin - minbin + 1);
Chris@929 374 for (int bin = ymin; bin <= ymax; ++bin) {
Chris@551 375 if (bin == minbin || bin == maxbin) continue;
Chris@551 376 if (values[bin - minbin] > values[bin - minbin - 1] &&
Chris@551 377 values[bin - minbin] > values[bin - minbin + 1]) {
Chris@275 378 peaks.insert(bin);
Chris@275 379 }
Chris@275 380 }
Chris@275 381 return peaks;
Chris@275 382 }
Chris@275 383
Chris@551 384 Column values = getColumn(x);
Chris@1154 385 int nv = int(values.size());
Chris@275 386
Chris@500 387 float mean = 0.f;
Chris@1154 388 for (int i = 0; i < nv; ++i) mean += values[i];
Chris@1154 389 if (nv > 0) mean = mean / float(values.size());
Chris@1038 390
Chris@275 391 // For peak picking we use a moving median window, picking the
Chris@275 392 // highest value within each continuous region of values that
Chris@275 393 // exceed the median. For pitch adaptivity, we adjust the window
Chris@275 394 // size to a roughly constant pitch range (about four tones).
Chris@275 395
Chris@1040 396 sv_samplerate_t sampleRate = getSampleRate();
Chris@275 397
Chris@1090 398 deque<float> window;
Chris@1090 399 vector<int> inrange;
Chris@280 400 float dist = 0.5;
Chris@500 401
Chris@929 402 int medianWinSize = getPeakPickWindowSize(type, sampleRate, ymin, dist);
Chris@929 403 int halfWin = medianWinSize/2;
Chris@275 404
Chris@929 405 int binmin;
Chris@275 406 if (ymin > halfWin) binmin = ymin - halfWin;
Chris@275 407 else binmin = 0;
Chris@275 408
Chris@929 409 int binmax;
Chris@1154 410 if (ymax + halfWin < nv) binmax = ymax + halfWin;
Chris@1154 411 else binmax = nv - 1;
Chris@275 412
Chris@929 413 int prevcentre = 0;
Chris@500 414
Chris@929 415 for (int bin = binmin; bin <= binmax; ++bin) {
Chris@275 416
Chris@275 417 float value = values[bin];
Chris@275 418
Chris@275 419 window.push_back(value);
Chris@275 420
Chris@280 421 // so-called median will actually be the dist*100'th percentile
Chris@280 422 medianWinSize = getPeakPickWindowSize(type, sampleRate, bin, dist);
Chris@275 423 halfWin = medianWinSize/2;
Chris@275 424
Chris@929 425 while ((int)window.size() > medianWinSize) {
Chris@500 426 window.pop_front();
Chris@500 427 }
Chris@500 428
Chris@1038 429 int actualSize = int(window.size());
Chris@275 430
Chris@275 431 if (type == MajorPitchAdaptivePeaks) {
Chris@1154 432 if (ymax + halfWin < nv) binmax = ymax + halfWin;
Chris@1154 433 else binmax = nv - 1;
Chris@275 434 }
Chris@275 435
Chris@1090 436 deque<float> sorted(window);
Chris@1090 437 sort(sorted.begin(), sorted.end());
Chris@1038 438 float median = sorted[int(float(sorted.size()) * dist)];
Chris@275 439
Chris@929 440 int centrebin = 0;
Chris@500 441 if (bin > actualSize/2) centrebin = bin - actualSize/2;
Chris@500 442
Chris@500 443 while (centrebin > prevcentre || bin == binmin) {
Chris@275 444
Chris@500 445 if (centrebin > prevcentre) ++prevcentre;
Chris@500 446
Chris@500 447 float centre = values[prevcentre];
Chris@500 448
Chris@500 449 if (centre > median) {
Chris@500 450 inrange.push_back(centrebin);
Chris@500 451 }
Chris@500 452
Chris@1154 453 if (centre <= median || centrebin+1 == nv) {
Chris@500 454 if (!inrange.empty()) {
Chris@929 455 int peakbin = 0;
Chris@500 456 float peakval = 0.f;
Chris@929 457 for (int i = 0; i < (int)inrange.size(); ++i) {
Chris@500 458 if (i == 0 || values[inrange[i]] > peakval) {
Chris@500 459 peakval = values[inrange[i]];
Chris@500 460 peakbin = inrange[i];
Chris@500 461 }
Chris@500 462 }
Chris@500 463 inrange.clear();
Chris@500 464 if (peakbin >= ymin && peakbin <= ymax) {
Chris@500 465 peaks.insert(peakbin);
Chris@275 466 }
Chris@275 467 }
Chris@275 468 }
Chris@500 469
Chris@500 470 if (bin == binmin) break;
Chris@275 471 }
Chris@275 472 }
Chris@275 473
Chris@275 474 return peaks;
Chris@275 475 }
Chris@275 476
Chris@929 477 int
Chris@1040 478 FFTModel::getPeakPickWindowSize(PeakPickType type, sv_samplerate_t sampleRate,
Chris@929 479 int bin, float &percentile) const
Chris@275 480 {
Chris@280 481 percentile = 0.5;
Chris@275 482 if (type == MajorPeaks) return 10;
Chris@275 483 if (bin == 0) return 3;
Chris@280 484
Chris@1091 485 double binfreq = (sampleRate * bin) / m_fftSize;
Chris@1038 486 double hifreq = Pitch::getFrequencyForPitch(73, 0, binfreq);
Chris@280 487
Chris@1091 488 int hibin = int(lrint((hifreq * m_fftSize) / sampleRate));
Chris@275 489 int medianWinSize = hibin - bin;
Chris@275 490 if (medianWinSize < 3) medianWinSize = 3;
Chris@280 491
Chris@1091 492 percentile = 0.5f + float(binfreq / sampleRate);
Chris@280 493
Chris@275 494 return medianWinSize;
Chris@275 495 }
Chris@275 496
Chris@275 497 FFTModel::PeakSet
Chris@929 498 FFTModel::getPeakFrequencies(PeakPickType type, int x,
Chris@929 499 int ymin, int ymax)
Chris@275 500 {
Chris@551 501 Profiler profiler("FFTModel::getPeakFrequencies");
Chris@551 502
Chris@275 503 PeakSet peaks;
Chris@275 504 if (!isOK()) return peaks;
Chris@275 505 PeakLocationSet locations = getPeaks(type, x, ymin, ymax);
Chris@275 506
Chris@1040 507 sv_samplerate_t sampleRate = getSampleRate();
Chris@929 508 int incr = getResolution();
Chris@275 509
Chris@275 510 // This duplicates some of the work of estimateStableFrequency to
Chris@275 511 // allow us to retrieve the phases in two separate vertical
Chris@275 512 // columns, instead of jumping back and forth between columns x and
Chris@275 513 // x+1, which may be significantly slower if re-seeking is needed
Chris@275 514
Chris@1090 515 vector<float> phases;
Chris@275 516 for (PeakLocationSet::iterator i = locations.begin();
Chris@275 517 i != locations.end(); ++i) {
Chris@275 518 phases.push_back(getPhaseAt(x, *i));
Chris@275 519 }
Chris@275 520
Chris@929 521 int phaseIndex = 0;
Chris@275 522 for (PeakLocationSet::iterator i = locations.begin();
Chris@275 523 i != locations.end(); ++i) {
Chris@1038 524 double oldPhase = phases[phaseIndex];
Chris@1038 525 double newPhase = getPhaseAt(x+1, *i);
Chris@1090 526 double expectedPhase = oldPhase + (2.0 * M_PI * *i * incr) / m_fftSize;
Chris@1038 527 double phaseError = princarg(newPhase - expectedPhase);
Chris@1038 528 double frequency =
Chris@275 529 (sampleRate * (expectedPhase + phaseError - oldPhase))
Chris@275 530 / (2 * M_PI * incr);
Chris@1045 531 peaks[*i] = frequency;
Chris@275 532 ++phaseIndex;
Chris@275 533 }
Chris@275 534
Chris@275 535 return peaks;
Chris@275 536 }
Chris@275 537