annotate data/model/FFTModel.cpp @ 1332:b1a7f4554400 svg

Implement "Export SVG file..."
author Chris Cannam
date Mon, 19 Dec 2016 16:32:34 +0000
parents 54af1e21705c
children fad8f533ca13
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@1256 21 #include "base/HitCount.h"
Chris@183 22
Chris@402 23 #include <algorithm>
Chris@402 24
Chris@152 25 #include <cassert>
Chris@1090 26 #include <deque>
Chris@152 27
Chris@1090 28 using namespace std;
Chris@1090 29
Chris@1256 30 static HitCount inSmallCache("FFTModel: Small FFT cache");
Chris@1256 31 static HitCount inSourceCache("FFTModel: Source data cache");
Chris@1256 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@1270 55 m_fft.initFloat();
Chris@1270 56
Chris@1133 57 connect(model, SIGNAL(modelChanged()), this, SIGNAL(modelChanged()));
Chris@1133 58 connect(model, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)),
Chris@1133 59 this, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)));
Chris@152 60 }
Chris@152 61
Chris@152 62 FFTModel::~FFTModel()
Chris@152 63 {
Chris@152 64 }
Chris@152 65
Chris@360 66 void
Chris@360 67 FFTModel::sourceModelAboutToBeDeleted()
Chris@360 68 {
Chris@1090 69 if (m_model) {
Chris@1090 70 cerr << "FFTModel[" << this << "]::sourceModelAboutToBeDeleted(" << m_model << ")" << endl;
Chris@1090 71 m_model = 0;
Chris@360 72 }
Chris@360 73 }
Chris@360 74
Chris@1091 75 int
Chris@1091 76 FFTModel::getWidth() const
Chris@1091 77 {
Chris@1091 78 if (!m_model) return 0;
Chris@1091 79 return int((m_model->getEndFrame() - m_model->getStartFrame())
Chris@1091 80 / m_windowIncrement) + 1;
Chris@1091 81 }
Chris@1091 82
Chris@1091 83 int
Chris@1091 84 FFTModel::getHeight() const
Chris@1091 85 {
Chris@1091 86 return m_fftSize / 2 + 1;
Chris@1091 87 }
Chris@1091 88
Chris@152 89 QString
Chris@929 90 FFTModel::getBinName(int n) const
Chris@152 91 {
Chris@1040 92 sv_samplerate_t sr = getSampleRate();
Chris@152 93 if (!sr) return "";
Chris@204 94 QString name = tr("%1 Hz").arg((n * sr) / ((getHeight()-1) * 2));
Chris@152 95 return name;
Chris@152 96 }
Chris@152 97
Chris@1091 98 FFTModel::Column
Chris@1091 99 FFTModel::getColumn(int x) const
Chris@1091 100 {
Chris@1091 101 auto cplx = getFFTColumn(x);
Chris@1091 102 Column col;
Chris@1154 103 col.reserve(cplx.size());
Chris@1091 104 for (auto c: cplx) col.push_back(abs(c));
Chris@1319 105 return col;
Chris@1091 106 }
Chris@1091 107
Chris@1200 108 FFTModel::Column
Chris@1200 109 FFTModel::getPhases(int x) const
Chris@1200 110 {
Chris@1200 111 auto cplx = getFFTColumn(x);
Chris@1200 112 Column col;
Chris@1200 113 col.reserve(cplx.size());
Chris@1201 114 for (auto c: cplx) {
Chris@1201 115 col.push_back(arg(c));
Chris@1201 116 }
Chris@1319 117 return col;
Chris@1200 118 }
Chris@1200 119
Chris@1091 120 float
Chris@1091 121 FFTModel::getMagnitudeAt(int x, int y) const
Chris@1091 122 {
Chris@1093 123 if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f;
Chris@1093 124 auto col = getFFTColumn(x);
Chris@1093 125 return abs(col[y]);
Chris@1091 126 }
Chris@1091 127
Chris@1091 128 float
Chris@1091 129 FFTModel::getMaximumMagnitudeAt(int x) const
Chris@1091 130 {
Chris@1091 131 Column col(getColumn(x));
Chris@1092 132 float max = 0.f;
Chris@1154 133 int n = int(col.size());
Chris@1154 134 for (int i = 0; i < n; ++i) {
Chris@1092 135 if (col[i] > max) max = col[i];
Chris@1092 136 }
Chris@1092 137 return max;
Chris@1091 138 }
Chris@1091 139
Chris@1091 140 float
Chris@1091 141 FFTModel::getPhaseAt(int x, int y) const
Chris@1091 142 {
Chris@1093 143 if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f;
Chris@1091 144 return arg(getFFTColumn(x)[y]);
Chris@1091 145 }
Chris@1091 146
Chris@1091 147 void
Chris@1091 148 FFTModel::getValuesAt(int x, int y, float &re, float &im) const
Chris@1091 149 {
Chris@1091 150 auto col = getFFTColumn(x);
Chris@1091 151 re = col[y].real();
Chris@1091 152 im = col[y].imag();
Chris@1091 153 }
Chris@1091 154
Chris@1091 155 bool
Chris@1091 156 FFTModel::getMagnitudesAt(int x, float *values, int minbin, int count) const
Chris@1091 157 {
Chris@1091 158 if (count == 0) count = getHeight();
Chris@1091 159 auto col = getFFTColumn(x);
Chris@1091 160 for (int i = 0; i < count; ++i) {
Chris@1091 161 values[i] = abs(col[minbin + i]);
Chris@1091 162 }
Chris@1091 163 return true;
Chris@1091 164 }
Chris@1091 165
Chris@1091 166 bool
Chris@1091 167 FFTModel::getPhasesAt(int x, float *values, int minbin, int count) const
Chris@1091 168 {
Chris@1091 169 if (count == 0) count = getHeight();
Chris@1091 170 auto col = getFFTColumn(x);
Chris@1091 171 for (int i = 0; i < count; ++i) {
Chris@1091 172 values[i] = arg(col[minbin + i]);
Chris@1091 173 }
Chris@1091 174 return true;
Chris@1091 175 }
Chris@1091 176
Chris@1091 177 bool
Chris@1091 178 FFTModel::getValuesAt(int x, float *reals, float *imags, int minbin, int count) const
Chris@1091 179 {
Chris@1091 180 if (count == 0) count = getHeight();
Chris@1091 181 auto col = getFFTColumn(x);
Chris@1091 182 for (int i = 0; i < count; ++i) {
Chris@1091 183 reals[i] = col[minbin + i].real();
Chris@1091 184 }
Chris@1091 185 for (int i = 0; i < count; ++i) {
Chris@1091 186 imags[i] = col[minbin + i].imag();
Chris@1091 187 }
Chris@1091 188 return true;
Chris@1091 189 }
Chris@1091 190
Chris@1326 191 FFTModel::fvec
Chris@1091 192 FFTModel::getSourceSamples(int column) const
Chris@1091 193 {
Chris@1094 194 // m_fftSize may be greater than m_windowSize, but not the reverse
Chris@1094 195
Chris@1094 196 // cerr << "getSourceSamples(" << column << ")" << endl;
Chris@1094 197
Chris@1091 198 auto range = getSourceSampleRange(column);
Chris@1094 199 auto data = getSourceData(range);
Chris@1094 200
Chris@1091 201 int off = (m_fftSize - m_windowSize) / 2;
Chris@1094 202
Chris@1094 203 if (off == 0) {
Chris@1094 204 return data;
Chris@1094 205 } else {
Chris@1094 206 vector<float> pad(off, 0.f);
Chris@1326 207 fvec padded;
Chris@1094 208 padded.reserve(m_fftSize);
Chris@1094 209 padded.insert(padded.end(), pad.begin(), pad.end());
Chris@1094 210 padded.insert(padded.end(), data.begin(), data.end());
Chris@1094 211 padded.insert(padded.end(), pad.begin(), pad.end());
Chris@1094 212 return padded;
Chris@1094 213 }
Chris@1094 214 }
Chris@1094 215
Chris@1326 216 FFTModel::fvec
Chris@1094 217 FFTModel::getSourceData(pair<sv_frame_t, sv_frame_t> range) const
Chris@1094 218 {
Chris@1094 219 // cerr << "getSourceData(" << range.first << "," << range.second
Chris@1094 220 // << "): saved range is (" << m_savedData.range.first
Chris@1094 221 // << "," << m_savedData.range.second << ")" << endl;
Chris@1094 222
Chris@1100 223 if (m_savedData.range == range) {
Chris@1256 224 inSourceCache.hit();
Chris@1100 225 return m_savedData.data;
Chris@1100 226 }
Chris@1094 227
Chris@1270 228 Profiler profiler("FFTModel::getSourceData (cache miss)");
Chris@1270 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@1256 234 inSourceCache.partial();
Chris@1256 235
Chris@1100 236 sv_frame_t discard = range.first - m_savedData.range.first;
Chris@1100 237
Chris@1326 238 fvec acc(m_savedData.data.begin() + discard, m_savedData.data.end());
Chris@1094 239
Chris@1326 240 fvec rest = 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@1256 249 inSourceCache.miss();
Chris@1256 250
Chris@1095 251 auto data = getSourceDataUncached(range);
Chris@1095 252 m_savedData = { range, data };
Chris@1095 253 return data;
Chris@1094 254 }
Chris@1095 255 }
Chris@1094 256
Chris@1326 257 FFTModel::fvec
Chris@1095 258 FFTModel::getSourceDataUncached(pair<sv_frame_t, sv_frame_t> range) const
Chris@1095 259 {
Chris@1091 260 decltype(range.first) pfx = 0;
Chris@1091 261 if (range.first < 0) {
Chris@1091 262 pfx = -range.first;
Chris@1091 263 range = { 0, range.second };
Chris@1091 264 }
Chris@1096 265
Chris@1096 266 auto data = m_model->getData(m_channel,
Chris@1096 267 range.first,
Chris@1096 268 range.second - range.first);
Chris@1096 269
Chris@1281 270 if (data.empty()) {
Chris@1281 271 SVDEBUG << "NOTE: empty source data for range (" << range.first << ","
Chris@1281 272 << range.second << ") (model end frame "
Chris@1281 273 << m_model->getEndFrame() << ")" << endl;
Chris@1281 274 }
Chris@1281 275
Chris@1096 276 // don't return a partial frame
Chris@1096 277 data.resize(range.second - range.first, 0.f);
Chris@1096 278
Chris@1096 279 if (pfx > 0) {
Chris@1096 280 vector<float> pad(pfx, 0.f);
Chris@1096 281 data.insert(data.begin(), pad.begin(), pad.end());
Chris@1096 282 }
Chris@1096 283
Chris@1091 284 if (m_channel == -1) {
Chris@1091 285 int channels = m_model->getChannelCount();
Chris@1091 286 if (channels > 1) {
Chris@1096 287 int n = int(data.size());
Chris@1096 288 float factor = 1.f / float(channels);
Chris@1100 289 // use mean instead of sum for fft model input
Chris@1096 290 for (int i = 0; i < n; ++i) {
Chris@1096 291 data[i] *= factor;
Chris@1091 292 }
Chris@1091 293 }
Chris@1091 294 }
Chris@1094 295
Chris@1094 296 return data;
Chris@1091 297 }
Chris@1091 298
Chris@1326 299 FFTModel::cvec
Chris@1093 300 FFTModel::getFFTColumn(int n) const
Chris@1091 301 {
Chris@1258 302 // The small cache (i.e. the m_cached deque) is for cases where
Chris@1258 303 // values are looked up individually, and for e.g. peak-frequency
Chris@1258 304 // spectrograms where values from two consecutive columns are
Chris@1257 305 // needed at once. This cache gets essentially no hits when
Chris@1258 306 // scrolling through a magnitude spectrogram, but 95%+ hits with a
Chris@1258 307 // peak-frequency spectrogram.
Chris@1257 308 for (const auto &incache : m_cached) {
Chris@1093 309 if (incache.n == n) {
Chris@1256 310 inSmallCache.hit();
Chris@1093 311 return incache.col;
Chris@1093 312 }
Chris@1093 313 }
Chris@1256 314 inSmallCache.miss();
Chris@1258 315
Chris@1258 316 Profiler profiler("FFTModel::getFFTColumn (cache miss)");
Chris@1093 317
Chris@1093 318 auto samples = getSourceSamples(n);
Chris@1100 319 m_windower.cut(samples.data());
Chris@1270 320 breakfastquay::v_fftshift(samples.data(), m_fftSize);
Chris@1270 321
Chris@1326 322 cvec col(m_fftSize/2 + 1);
Chris@1270 323
Chris@1270 324 m_fft.forwardInterleaved(samples.data(),
Chris@1270 325 reinterpret_cast<float *>(col.data()));
Chris@1093 326
Chris@1093 327 SavedColumn sc { n, col };
Chris@1093 328 if (m_cached.size() >= m_cacheSize) {
Chris@1093 329 m_cached.pop_front();
Chris@1093 330 }
Chris@1093 331 m_cached.push_back(sc);
Chris@1093 332
Chris@1319 333 return col;
Chris@1091 334 }
Chris@1091 335
Chris@275 336 bool
Chris@1045 337 FFTModel::estimateStableFrequency(int x, int y, double &frequency)
Chris@275 338 {
Chris@275 339 if (!isOK()) return false;
Chris@275 340
Chris@1090 341 frequency = double(y * getSampleRate()) / m_fftSize;
Chris@275 342
Chris@275 343 if (x+1 >= getWidth()) return false;
Chris@275 344
Chris@275 345 // At frequency f, a phase shift of 2pi (one cycle) happens in 1/f sec.
Chris@275 346 // At hopsize h and sample rate sr, one hop happens in h/sr sec.
Chris@275 347 // At window size w, for bin b, f is b*sr/w.
Chris@275 348 // thus 2pi phase shift happens in w/(b*sr) sec.
Chris@275 349 // We need to know what phase shift we expect from h/sr sec.
Chris@275 350 // -> 2pi * ((h/sr) / (w/(b*sr)))
Chris@275 351 // = 2pi * ((h * b * sr) / (w * sr))
Chris@275 352 // = 2pi * (h * b) / w.
Chris@275 353
Chris@1038 354 double oldPhase = getPhaseAt(x, y);
Chris@1038 355 double newPhase = getPhaseAt(x+1, y);
Chris@275 356
Chris@929 357 int incr = getResolution();
Chris@275 358
Chris@1090 359 double expectedPhase = oldPhase + (2.0 * M_PI * y * incr) / m_fftSize;
Chris@275 360
Chris@1038 361 double phaseError = princarg(newPhase - expectedPhase);
Chris@275 362
Chris@275 363 // The new frequency estimate based on the phase error resulting
Chris@275 364 // from assuming the "native" frequency of this bin
Chris@275 365
Chris@275 366 frequency =
Chris@1090 367 (getSampleRate() * (expectedPhase + phaseError - oldPhase)) /
Chris@1045 368 (2.0 * M_PI * incr);
Chris@275 369
Chris@275 370 return true;
Chris@275 371 }
Chris@275 372
Chris@275 373 FFTModel::PeakLocationSet
Chris@1191 374 FFTModel::getPeaks(PeakPickType type, int x, int ymin, int ymax) const
Chris@275 375 {
Chris@551 376 Profiler profiler("FFTModel::getPeaks");
Chris@551 377
Chris@275 378 FFTModel::PeakLocationSet peaks;
Chris@275 379 if (!isOK()) return peaks;
Chris@275 380
Chris@275 381 if (ymax == 0 || ymax > getHeight() - 1) {
Chris@275 382 ymax = getHeight() - 1;
Chris@275 383 }
Chris@275 384
Chris@275 385 if (type == AllPeaks) {
Chris@551 386 int minbin = ymin;
Chris@551 387 if (minbin > 0) minbin = minbin - 1;
Chris@551 388 int maxbin = ymax;
Chris@551 389 if (maxbin < getHeight() - 1) maxbin = maxbin + 1;
Chris@551 390 const int n = maxbin - minbin + 1;
Chris@1218 391 float *values = new float[n];
Chris@551 392 getMagnitudesAt(x, values, minbin, maxbin - minbin + 1);
Chris@929 393 for (int bin = ymin; bin <= ymax; ++bin) {
Chris@551 394 if (bin == minbin || bin == maxbin) continue;
Chris@551 395 if (values[bin - minbin] > values[bin - minbin - 1] &&
Chris@551 396 values[bin - minbin] > values[bin - minbin + 1]) {
Chris@275 397 peaks.insert(bin);
Chris@275 398 }
Chris@275 399 }
Chris@1218 400 delete[] values;
Chris@275 401 return peaks;
Chris@275 402 }
Chris@275 403
Chris@551 404 Column values = getColumn(x);
Chris@1154 405 int nv = int(values.size());
Chris@275 406
Chris@500 407 float mean = 0.f;
Chris@1154 408 for (int i = 0; i < nv; ++i) mean += values[i];
Chris@1154 409 if (nv > 0) mean = mean / float(values.size());
Chris@1038 410
Chris@275 411 // For peak picking we use a moving median window, picking the
Chris@275 412 // highest value within each continuous region of values that
Chris@275 413 // exceed the median. For pitch adaptivity, we adjust the window
Chris@275 414 // size to a roughly constant pitch range (about four tones).
Chris@275 415
Chris@1040 416 sv_samplerate_t sampleRate = getSampleRate();
Chris@275 417
Chris@1090 418 deque<float> window;
Chris@1090 419 vector<int> inrange;
Chris@280 420 float dist = 0.5;
Chris@500 421
Chris@929 422 int medianWinSize = getPeakPickWindowSize(type, sampleRate, ymin, dist);
Chris@929 423 int halfWin = medianWinSize/2;
Chris@275 424
Chris@929 425 int binmin;
Chris@275 426 if (ymin > halfWin) binmin = ymin - halfWin;
Chris@275 427 else binmin = 0;
Chris@275 428
Chris@929 429 int binmax;
Chris@1154 430 if (ymax + halfWin < nv) binmax = ymax + halfWin;
Chris@1154 431 else binmax = nv - 1;
Chris@275 432
Chris@929 433 int prevcentre = 0;
Chris@500 434
Chris@929 435 for (int bin = binmin; bin <= binmax; ++bin) {
Chris@275 436
Chris@275 437 float value = values[bin];
Chris@275 438
Chris@275 439 window.push_back(value);
Chris@275 440
Chris@280 441 // so-called median will actually be the dist*100'th percentile
Chris@280 442 medianWinSize = getPeakPickWindowSize(type, sampleRate, bin, dist);
Chris@275 443 halfWin = medianWinSize/2;
Chris@275 444
Chris@929 445 while ((int)window.size() > medianWinSize) {
Chris@500 446 window.pop_front();
Chris@500 447 }
Chris@500 448
Chris@1038 449 int actualSize = int(window.size());
Chris@275 450
Chris@275 451 if (type == MajorPitchAdaptivePeaks) {
Chris@1154 452 if (ymax + halfWin < nv) binmax = ymax + halfWin;
Chris@1154 453 else binmax = nv - 1;
Chris@275 454 }
Chris@275 455
Chris@1090 456 deque<float> sorted(window);
Chris@1090 457 sort(sorted.begin(), sorted.end());
Chris@1038 458 float median = sorted[int(float(sorted.size()) * dist)];
Chris@275 459
Chris@929 460 int centrebin = 0;
Chris@500 461 if (bin > actualSize/2) centrebin = bin - actualSize/2;
Chris@500 462
Chris@500 463 while (centrebin > prevcentre || bin == binmin) {
Chris@275 464
Chris@500 465 if (centrebin > prevcentre) ++prevcentre;
Chris@500 466
Chris@500 467 float centre = values[prevcentre];
Chris@500 468
Chris@500 469 if (centre > median) {
Chris@500 470 inrange.push_back(centrebin);
Chris@500 471 }
Chris@500 472
Chris@1154 473 if (centre <= median || centrebin+1 == nv) {
Chris@500 474 if (!inrange.empty()) {
Chris@929 475 int peakbin = 0;
Chris@500 476 float peakval = 0.f;
Chris@929 477 for (int i = 0; i < (int)inrange.size(); ++i) {
Chris@500 478 if (i == 0 || values[inrange[i]] > peakval) {
Chris@500 479 peakval = values[inrange[i]];
Chris@500 480 peakbin = inrange[i];
Chris@500 481 }
Chris@500 482 }
Chris@500 483 inrange.clear();
Chris@500 484 if (peakbin >= ymin && peakbin <= ymax) {
Chris@500 485 peaks.insert(peakbin);
Chris@275 486 }
Chris@275 487 }
Chris@275 488 }
Chris@500 489
Chris@500 490 if (bin == binmin) break;
Chris@275 491 }
Chris@275 492 }
Chris@275 493
Chris@275 494 return peaks;
Chris@275 495 }
Chris@275 496
Chris@929 497 int
Chris@1040 498 FFTModel::getPeakPickWindowSize(PeakPickType type, sv_samplerate_t sampleRate,
Chris@929 499 int bin, float &percentile) const
Chris@275 500 {
Chris@280 501 percentile = 0.5;
Chris@275 502 if (type == MajorPeaks) return 10;
Chris@275 503 if (bin == 0) return 3;
Chris@280 504
Chris@1091 505 double binfreq = (sampleRate * bin) / m_fftSize;
Chris@1038 506 double hifreq = Pitch::getFrequencyForPitch(73, 0, binfreq);
Chris@280 507
Chris@1091 508 int hibin = int(lrint((hifreq * m_fftSize) / sampleRate));
Chris@275 509 int medianWinSize = hibin - bin;
Chris@275 510 if (medianWinSize < 3) medianWinSize = 3;
Chris@280 511
Chris@1091 512 percentile = 0.5f + float(binfreq / sampleRate);
Chris@280 513
Chris@275 514 return medianWinSize;
Chris@275 515 }
Chris@275 516
Chris@275 517 FFTModel::PeakSet
Chris@929 518 FFTModel::getPeakFrequencies(PeakPickType type, int x,
Chris@1191 519 int ymin, int ymax) const
Chris@275 520 {
Chris@551 521 Profiler profiler("FFTModel::getPeakFrequencies");
Chris@551 522
Chris@275 523 PeakSet peaks;
Chris@275 524 if (!isOK()) return peaks;
Chris@275 525 PeakLocationSet locations = getPeaks(type, x, ymin, ymax);
Chris@275 526
Chris@1040 527 sv_samplerate_t sampleRate = getSampleRate();
Chris@929 528 int incr = getResolution();
Chris@275 529
Chris@275 530 // This duplicates some of the work of estimateStableFrequency to
Chris@275 531 // allow us to retrieve the phases in two separate vertical
Chris@275 532 // columns, instead of jumping back and forth between columns x and
Chris@275 533 // x+1, which may be significantly slower if re-seeking is needed
Chris@275 534
Chris@1090 535 vector<float> phases;
Chris@275 536 for (PeakLocationSet::iterator i = locations.begin();
Chris@275 537 i != locations.end(); ++i) {
Chris@275 538 phases.push_back(getPhaseAt(x, *i));
Chris@275 539 }
Chris@275 540
Chris@929 541 int phaseIndex = 0;
Chris@275 542 for (PeakLocationSet::iterator i = locations.begin();
Chris@275 543 i != locations.end(); ++i) {
Chris@1038 544 double oldPhase = phases[phaseIndex];
Chris@1038 545 double newPhase = getPhaseAt(x+1, *i);
Chris@1090 546 double expectedPhase = oldPhase + (2.0 * M_PI * *i * incr) / m_fftSize;
Chris@1038 547 double phaseError = princarg(newPhase - expectedPhase);
Chris@1038 548 double frequency =
Chris@275 549 (sampleRate * (expectedPhase + phaseError - oldPhase))
Chris@275 550 / (2 * M_PI * incr);
Chris@1045 551 peaks[*i] = frequency;
Chris@275 552 ++phaseIndex;
Chris@275 553 }
Chris@275 554
Chris@275 555 return peaks;
Chris@275 556 }
Chris@275 557