annotate plugins/SimilarityPlugin.cpp @ 45:5d7ce1d87301

* Add MFCC plugin * Add means output to Chromagram plugin * Update similarity plugin for MFCC changes
author Chris Cannam <c.cannam@qmul.ac.uk>
date Fri, 18 Jan 2008 13:30:56 +0000
parents 1dc00e4dbae6
children 26a2e341d358
rev   line source
c@41 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
c@41 2
c@41 3 /*
c@41 4 * SegmenterPlugin.cpp
c@41 5 *
c@41 6 * Copyright 2008 Centre for Digital Music, Queen Mary, University of London.
c@41 7 * All rights reserved.
c@41 8 */
c@41 9
c@41 10 #include <iostream>
c@44 11 #include <cstdio>
c@41 12
c@41 13 #include "SimilarityPlugin.h"
c@42 14 #include "base/Pitch.h"
c@41 15 #include "dsp/mfcc/MFCC.h"
c@42 16 #include "dsp/chromagram/Chromagram.h"
c@41 17 #include "dsp/rateconversion/Decimator.h"
c@41 18
c@41 19 using std::string;
c@41 20 using std::vector;
c@41 21 using std::cerr;
c@41 22 using std::endl;
c@41 23 using std::ostringstream;
c@41 24
c@41 25 SimilarityPlugin::SimilarityPlugin(float inputSampleRate) :
c@41 26 Plugin(inputSampleRate),
c@42 27 m_type(TypeMFCC),
c@41 28 m_mfcc(0),
c@42 29 m_chromagram(0),
c@41 30 m_decimator(0),
c@42 31 m_featureColumnSize(20),
c@41 32 m_blockSize(0),
c@41 33 m_channels(0)
c@41 34 {
c@41 35
c@41 36 }
c@41 37
c@41 38 SimilarityPlugin::~SimilarityPlugin()
c@41 39 {
c@41 40 delete m_mfcc;
c@42 41 delete m_chromagram;
c@41 42 delete m_decimator;
c@41 43 }
c@41 44
c@41 45 string
c@41 46 SimilarityPlugin::getIdentifier() const
c@41 47 {
c@41 48 return "qm-similarity";
c@41 49 }
c@41 50
c@41 51 string
c@41 52 SimilarityPlugin::getName() const
c@41 53 {
c@41 54 return "Similarity";
c@41 55 }
c@41 56
c@41 57 string
c@41 58 SimilarityPlugin::getDescription() const
c@41 59 {
c@42 60 return "Return a distance matrix for similarity between the input audio channels";
c@41 61 }
c@41 62
c@41 63 string
c@41 64 SimilarityPlugin::getMaker() const
c@41 65 {
c@45 66 return "Mark Levy and Chris Cannam, Queen Mary, University of London";
c@41 67 }
c@41 68
c@41 69 int
c@41 70 SimilarityPlugin::getPluginVersion() const
c@41 71 {
c@41 72 return 1;
c@41 73 }
c@41 74
c@41 75 string
c@41 76 SimilarityPlugin::getCopyright() const
c@41 77 {
c@41 78 return "Copyright (c) 2008 - All Rights Reserved";
c@41 79 }
c@41 80
c@41 81 size_t
c@41 82 SimilarityPlugin::getMinChannelCount() const
c@41 83 {
c@43 84 return 1;
c@41 85 }
c@41 86
c@41 87 size_t
c@41 88 SimilarityPlugin::getMaxChannelCount() const
c@41 89 {
c@41 90 return 1024;
c@41 91 }
c@41 92
c@41 93 bool
c@41 94 SimilarityPlugin::initialise(size_t channels, size_t stepSize, size_t blockSize)
c@41 95 {
c@41 96 if (channels < getMinChannelCount() ||
c@41 97 channels > getMaxChannelCount()) return false;
c@41 98
c@41 99 if (stepSize != getPreferredStepSize()) {
c@43 100 //!!! actually this perhaps shouldn't be an error... similarly
c@43 101 //using more than getMaxChannelCount channels
c@41 102 std::cerr << "SimilarityPlugin::initialise: supplied step size "
c@41 103 << stepSize << " differs from required step size "
c@41 104 << getPreferredStepSize() << std::endl;
c@41 105 return false;
c@41 106 }
c@41 107
c@41 108 if (blockSize != getPreferredBlockSize()) {
c@41 109 std::cerr << "SimilarityPlugin::initialise: supplied block size "
c@41 110 << blockSize << " differs from required block size "
c@41 111 << getPreferredBlockSize() << std::endl;
c@41 112 return false;
c@41 113 }
c@41 114
c@41 115 m_blockSize = blockSize;
c@41 116 m_channels = channels;
c@41 117
c@44 118 m_lastNonEmptyFrame = std::vector<int>(m_channels);
c@44 119 for (int i = 0; i < m_channels; ++i) m_lastNonEmptyFrame[i] = -1;
c@44 120 m_frameNo = 0;
c@44 121
c@41 122 int decimationFactor = getDecimationFactor();
c@41 123 if (decimationFactor > 1) {
c@42 124 m_decimator = new Decimator(m_blockSize, decimationFactor);
c@41 125 }
c@41 126
c@42 127 if (m_type == TypeMFCC) {
c@42 128
c@42 129 m_featureColumnSize = 20;
c@42 130
c@45 131 MFCCConfig config(lrintf(m_inputSampleRate) / decimationFactor);
c@42 132 config.fftsize = 2048;
c@42 133 config.nceps = m_featureColumnSize - 1;
c@42 134 config.want_c0 = true;
c@45 135 config.logpower = 1;
c@42 136 m_mfcc = new MFCC(config);
c@42 137 m_fftSize = m_mfcc->getfftlength();
c@42 138
c@43 139 std::cerr << "MFCC FS = " << config.FS << ", FFT size = " << m_fftSize<< std::endl;
c@43 140
c@42 141 } else if (m_type == TypeChroma) {
c@42 142
c@42 143 m_featureColumnSize = 12;
c@42 144
c@42 145 ChromaConfig config;
c@42 146 config.FS = lrintf(m_inputSampleRate) / decimationFactor;
c@42 147 config.min = Pitch::getFrequencyForPitch(24, 0, 440);
c@42 148 config.max = Pitch::getFrequencyForPitch(96, 0, 440);
c@42 149 config.BPO = 12;
c@42 150 config.CQThresh = 0.0054;
c@42 151 config.isNormalised = true;
c@42 152 m_chromagram = new Chromagram(config);
c@42 153 m_fftSize = m_chromagram->getFrameSize();
c@42 154
c@42 155 std::cerr << "min = "<< config.min << ", max = " << config.max << std::endl;
c@42 156
c@42 157 } else {
c@42 158
c@42 159 std::cerr << "SimilarityPlugin::initialise: internal error: unknown type " << m_type << std::endl;
c@42 160 return false;
c@42 161 }
c@41 162
c@41 163 for (int i = 0; i < m_channels; ++i) {
c@42 164 m_values.push_back(FeatureMatrix());
c@41 165 }
c@41 166
c@41 167 return true;
c@41 168 }
c@41 169
c@41 170 void
c@41 171 SimilarityPlugin::reset()
c@41 172 {
c@41 173 //!!!
c@41 174 }
c@41 175
c@41 176 int
c@41 177 SimilarityPlugin::getDecimationFactor() const
c@41 178 {
c@41 179 int rate = lrintf(m_inputSampleRate);
c@41 180 int internalRate = 22050;
c@41 181 int decimationFactor = rate / internalRate;
c@41 182 if (decimationFactor < 1) decimationFactor = 1;
c@41 183
c@41 184 // must be a power of two
c@41 185 while (decimationFactor & (decimationFactor - 1)) ++decimationFactor;
c@41 186
c@41 187 return decimationFactor;
c@41 188 }
c@41 189
c@41 190 size_t
c@41 191 SimilarityPlugin::getPreferredStepSize() const
c@41 192 {
c@42 193 if (m_blockSize == 0) calculateBlockSize();
c@45 194 return m_blockSize/2;
c@41 195 }
c@41 196
c@41 197 size_t
c@41 198 SimilarityPlugin::getPreferredBlockSize() const
c@41 199 {
c@42 200 if (m_blockSize == 0) calculateBlockSize();
c@42 201 return m_blockSize;
c@42 202 }
c@42 203
c@42 204 void
c@42 205 SimilarityPlugin::calculateBlockSize() const
c@42 206 {
c@42 207 if (m_blockSize != 0) return;
c@42 208 int decimationFactor = getDecimationFactor();
c@42 209 if (m_type == TypeChroma) {
c@42 210 ChromaConfig config;
c@42 211 config.FS = lrintf(m_inputSampleRate) / decimationFactor;
c@42 212 config.min = Pitch::getFrequencyForPitch(24, 0, 440);
c@42 213 config.max = Pitch::getFrequencyForPitch(96, 0, 440);
c@42 214 config.BPO = 12;
c@42 215 config.CQThresh = 0.0054;
c@42 216 config.isNormalised = false;
c@42 217 Chromagram *c = new Chromagram(config);
c@42 218 size_t sz = c->getFrameSize();
c@42 219 delete c;
c@42 220 m_blockSize = sz * decimationFactor;
c@42 221 } else {
c@42 222 m_blockSize = 2048 * decimationFactor;
c@42 223 }
c@41 224 }
c@41 225
c@41 226 SimilarityPlugin::ParameterList SimilarityPlugin::getParameterDescriptors() const
c@41 227 {
c@41 228 ParameterList list;
c@42 229
c@42 230 ParameterDescriptor desc;
c@42 231 desc.identifier = "featureType";
c@42 232 desc.name = "Feature Type";
c@45 233 desc.description = "Audio feature used for similarity measure. Timbral: use the first 20 MFCCs (19 plus C0). Chromatic: use 12 bin-per-octave chroma.";
c@42 234 desc.unit = "";
c@42 235 desc.minValue = 0;
c@42 236 desc.maxValue = 1;
c@42 237 desc.defaultValue = 0;
c@42 238 desc.isQuantized = true;
c@42 239 desc.quantizeStep = 1;
c@42 240 desc.valueNames.push_back("Timbral (MFCC)");
c@42 241 desc.valueNames.push_back("Chromatic (Chroma)");
c@42 242 list.push_back(desc);
c@42 243
c@41 244 return list;
c@41 245 }
c@41 246
c@41 247 float
c@41 248 SimilarityPlugin::getParameter(std::string param) const
c@41 249 {
c@42 250 if (param == "featureType") {
c@42 251 if (m_type == TypeMFCC) return 0;
c@42 252 else if (m_type == TypeChroma) return 1;
c@42 253 else return 0;
c@42 254 }
c@42 255
c@41 256 std::cerr << "WARNING: SimilarityPlugin::getParameter: unknown parameter \""
c@41 257 << param << "\"" << std::endl;
c@41 258 return 0.0;
c@41 259 }
c@41 260
c@41 261 void
c@41 262 SimilarityPlugin::setParameter(std::string param, float value)
c@41 263 {
c@42 264 if (param == "featureType") {
c@42 265 int v = int(value + 0.1);
c@42 266 Type prevType = m_type;
c@42 267 if (v == 0) m_type = TypeMFCC;
c@42 268 else if (v == 1) m_type = TypeChroma;
c@42 269 if (m_type != prevType) m_blockSize = 0;
c@42 270 return;
c@42 271 }
c@42 272
c@41 273 std::cerr << "WARNING: SimilarityPlugin::setParameter: unknown parameter \""
c@41 274 << param << "\"" << std::endl;
c@41 275 }
c@41 276
c@41 277 SimilarityPlugin::OutputList
c@41 278 SimilarityPlugin::getOutputDescriptors() const
c@41 279 {
c@41 280 OutputList list;
c@41 281
c@41 282 OutputDescriptor similarity;
c@43 283 similarity.identifier = "distancematrix";
c@43 284 similarity.name = "Distance Matrix";
c@43 285 similarity.description = "Distance matrix for similarity metric. Smaller = more similar. Should be symmetrical.";
c@41 286 similarity.unit = "";
c@41 287 similarity.hasFixedBinCount = true;
c@41 288 similarity.binCount = m_channels;
c@41 289 similarity.hasKnownExtents = false;
c@41 290 similarity.isQuantized = false;
c@41 291 similarity.sampleType = OutputDescriptor::FixedSampleRate;
c@41 292 similarity.sampleRate = 1;
c@41 293
c@43 294 m_distanceMatrixOutput = list.size();
c@41 295 list.push_back(similarity);
c@41 296
c@43 297 OutputDescriptor simvec;
c@43 298 simvec.identifier = "distancevector";
c@43 299 simvec.name = "Distance from First Channel";
c@43 300 simvec.description = "Distance vector for similarity of each channel to the first channel. Smaller = more similar.";
c@43 301 simvec.unit = "";
c@43 302 simvec.hasFixedBinCount = true;
c@43 303 simvec.binCount = m_channels;
c@43 304 simvec.hasKnownExtents = false;
c@43 305 simvec.isQuantized = false;
c@43 306 simvec.sampleType = OutputDescriptor::FixedSampleRate;
c@43 307 simvec.sampleRate = 1;
c@43 308
c@43 309 m_distanceVectorOutput = list.size();
c@43 310 list.push_back(simvec);
c@43 311
c@44 312 OutputDescriptor sortvec;
c@44 313 sortvec.identifier = "sorteddistancevector";
c@44 314 sortvec.name = "Ordered Distances from First Channel";
c@44 315 sortvec.description = "Vector of the order of other channels in similarity to the first, followed by distance vector for similarity of each to the first. Smaller = more similar.";
c@44 316 sortvec.unit = "";
c@44 317 sortvec.hasFixedBinCount = true;
c@44 318 sortvec.binCount = m_channels;
c@44 319 sortvec.hasKnownExtents = false;
c@44 320 sortvec.isQuantized = false;
c@44 321 sortvec.sampleType = OutputDescriptor::FixedSampleRate;
c@44 322 sortvec.sampleRate = 1;
c@44 323
c@44 324 m_sortedVectorOutput = list.size();
c@44 325 list.push_back(sortvec);
c@44 326
c@41 327 OutputDescriptor means;
c@41 328 means.identifier = "means";
c@42 329 means.name = "Feature Means";
c@43 330 means.description = "Means of the feature bins. Feature time (sec) corresponds to input channel. Number of bins depends on selected feature type.";
c@41 331 means.unit = "";
c@41 332 means.hasFixedBinCount = true;
c@43 333 means.binCount = m_featureColumnSize;
c@41 334 means.hasKnownExtents = false;
c@41 335 means.isQuantized = false;
c@43 336 means.sampleType = OutputDescriptor::FixedSampleRate;
c@43 337 means.sampleRate = 1;
c@41 338
c@43 339 m_meansOutput = list.size();
c@41 340 list.push_back(means);
c@41 341
c@41 342 OutputDescriptor variances;
c@41 343 variances.identifier = "variances";
c@42 344 variances.name = "Feature Variances";
c@43 345 variances.description = "Variances of the feature bins. Feature time (sec) corresponds to input channel. Number of bins depends on selected feature type.";
c@41 346 variances.unit = "";
c@41 347 variances.hasFixedBinCount = true;
c@43 348 variances.binCount = m_featureColumnSize;
c@41 349 variances.hasKnownExtents = false;
c@41 350 variances.isQuantized = false;
c@43 351 variances.sampleType = OutputDescriptor::FixedSampleRate;
c@43 352 variances.sampleRate = 1;
c@41 353
c@43 354 m_variancesOutput = list.size();
c@41 355 list.push_back(variances);
c@41 356
c@41 357 return list;
c@41 358 }
c@41 359
c@41 360 SimilarityPlugin::FeatureSet
c@41 361 SimilarityPlugin::process(const float *const *inputBuffers, Vamp::RealTime /* timestamp */)
c@41 362 {
c@41 363 double *dblbuf = new double[m_blockSize];
c@41 364 double *decbuf = dblbuf;
c@42 365 if (m_decimator) decbuf = new double[m_fftSize];
c@42 366
c@42 367 double *raw = 0;
c@42 368 bool ownRaw = false;
c@42 369
c@42 370 if (m_type == TypeMFCC) {
c@42 371 raw = new double[m_featureColumnSize];
c@42 372 ownRaw = true;
c@42 373 }
c@41 374
c@43 375 float threshold = 1e-10;
c@43 376
c@41 377 for (size_t c = 0; c < m_channels; ++c) {
c@41 378
c@43 379 bool empty = true;
c@43 380
c@41 381 for (int i = 0; i < m_blockSize; ++i) {
c@43 382 float val = inputBuffers[c][i];
c@43 383 if (fabs(val) > threshold) empty = false;
c@43 384 dblbuf[i] = val;
c@41 385 }
c@41 386
c@43 387 if (empty) continue;
c@44 388 m_lastNonEmptyFrame[c] = m_frameNo;
c@43 389
c@41 390 if (m_decimator) {
c@41 391 m_decimator->process(dblbuf, decbuf);
c@41 392 }
c@42 393
c@42 394 if (m_type == TypeMFCC) {
c@45 395 m_mfcc->process(decbuf, raw);
c@42 396 } else if (m_type == TypeChroma) {
c@42 397 raw = m_chromagram->process(decbuf);
c@42 398 }
c@41 399
c@42 400 FeatureColumn mf(m_featureColumnSize);
c@44 401 // std::cout << m_frameNo << ":" << c << ": ";
c@44 402 for (int i = 0; i < m_featureColumnSize; ++i) {
c@44 403 mf[i] = raw[i];
c@44 404 // std::cout << raw[i] << " ";
c@44 405 }
c@44 406 // std::cout << std::endl;
c@41 407
c@42 408 m_values[c].push_back(mf);
c@41 409 }
c@41 410
c@41 411 if (m_decimator) delete[] decbuf;
c@41 412 delete[] dblbuf;
c@42 413
c@42 414 if (ownRaw) delete[] raw;
c@41 415
c@44 416 ++m_frameNo;
c@44 417
c@41 418 return FeatureSet();
c@41 419 }
c@41 420
c@41 421 SimilarityPlugin::FeatureSet
c@41 422 SimilarityPlugin::getRemainingFeatures()
c@41 423 {
c@42 424 std::vector<FeatureColumn> m(m_channels);
c@42 425 std::vector<FeatureColumn> v(m_channels);
c@41 426
c@41 427 for (int i = 0; i < m_channels; ++i) {
c@41 428
c@42 429 FeatureColumn mean(m_featureColumnSize), variance(m_featureColumnSize);
c@41 430
c@42 431 for (int j = 0; j < m_featureColumnSize; ++j) {
c@41 432
c@43 433 mean[j] = 0.0;
c@43 434 variance[j] = 0.0;
c@41 435 int count;
c@41 436
c@44 437 // We want to take values up to, but not including, the
c@44 438 // last non-empty frame (which may be partial)
c@43 439
c@44 440 int sz = m_lastNonEmptyFrame[i];
c@44 441 if (sz < 0) sz = 0;
c@43 442
c@43 443 // std::cout << "\nBin " << j << ":" << std::endl;
c@42 444
c@41 445 count = 0;
c@43 446 for (int k = 0; k < sz; ++k) {
c@42 447 double val = m_values[i][k][j];
c@42 448 // std::cout << val << " ";
c@41 449 if (isnan(val) || isinf(val)) continue;
c@41 450 mean[j] += val;
c@41 451 ++count;
c@41 452 }
c@41 453 if (count > 0) mean[j] /= count;
c@43 454 // std::cout << "\n" << count << " non-NaN non-inf values, so mean = " << mean[j] << std::endl;
c@41 455
c@41 456 count = 0;
c@43 457 for (int k = 0; k < sz; ++k) {
c@42 458 double val = ((m_values[i][k][j] - mean[j]) *
c@42 459 (m_values[i][k][j] - mean[j]));
c@41 460 if (isnan(val) || isinf(val)) continue;
c@41 461 variance[j] += val;
c@41 462 ++count;
c@41 463 }
c@41 464 if (count > 0) variance[j] /= count;
c@43 465 // std::cout << "... and variance = " << variance[j] << std::endl;
c@41 466 }
c@41 467
c@41 468 m[i] = mean;
c@41 469 v[i] = variance;
c@41 470 }
c@41 471
c@42 472 // we want to return a matrix of the distances between channels,
c@41 473 // but Vamp doesn't have a matrix return type so we actually
c@41 474 // return a series of vectors
c@41 475
c@41 476 std::vector<std::vector<double> > distances;
c@41 477
c@42 478 // "Despite the fact that MFCCs extracted from music are clearly
c@42 479 // not Gaussian, [14] showed, somewhat surprisingly, that a
c@42 480 // similarity function comparing single Gaussians modelling MFCCs
c@42 481 // for each track can perform as well as mixture models. A great
c@42 482 // advantage of using single Gaussians is that a simple closed
c@42 483 // form exists for the KL divergence." -- Mark Levy, "Lightweight
c@42 484 // measures for timbral similarity of musical audio"
c@42 485 // (http://www.elec.qmul.ac.uk/easaier/papers/mlevytimbralsimilarity.pdf)
c@42 486 //
c@42 487 // This code calculates a symmetrised distance metric based on the
c@42 488 // KL divergence of Gaussian models of the MFCC values.
c@42 489
c@41 490 for (int i = 0; i < m_channels; ++i) {
c@41 491 distances.push_back(std::vector<double>());
c@41 492 for (int j = 0; j < m_channels; ++j) {
c@42 493 double d = -2.0 * m_featureColumnSize;
c@42 494 for (int k = 0; k < m_featureColumnSize; ++k) {
c@42 495 // m[i][k] is the mean of feature bin k for channel i
c@42 496 // v[i][k] is the variance of feature bin k for channel i
c@41 497 d += v[i][k] / v[j][k] + v[j][k] / v[i][k];
c@41 498 d += (m[i][k] - m[j][k])
c@41 499 * (1.0 / v[i][k] + 1.0 / v[j][k])
c@41 500 * (m[i][k] - m[j][k]);
c@41 501 }
c@41 502 d /= 2.0;
c@41 503 distances[i].push_back(d);
c@41 504 }
c@41 505 }
c@41 506
c@44 507 // We give all features a timestamp, otherwise hosts will tend to
c@44 508 // stamp them at the end of the file, which is annoying
c@44 509
c@41 510 FeatureSet returnFeatures;
c@41 511
c@44 512 Feature feature;
c@44 513 feature.hasTimestamp = true;
c@44 514
c@43 515 Feature distanceVectorFeature;
c@43 516 distanceVectorFeature.label = "Distance from first channel";
c@44 517 distanceVectorFeature.hasTimestamp = true;
c@44 518 distanceVectorFeature.timestamp = Vamp::RealTime::zeroTime;
c@44 519
c@44 520 std::map<double, int> sorted;
c@44 521
c@44 522 char labelBuffer[100];
c@43 523
c@41 524 for (int i = 0; i < m_channels; ++i) {
c@41 525
c@41 526 feature.timestamp = Vamp::RealTime(i, 0);
c@41 527
c@44 528 sprintf(labelBuffer, "Means for channel %d", i+1);
c@44 529 feature.label = labelBuffer;
c@44 530
c@41 531 feature.values.clear();
c@42 532 for (int k = 0; k < m_featureColumnSize; ++k) {
c@41 533 feature.values.push_back(m[i][k]);
c@41 534 }
c@41 535
c@43 536 returnFeatures[m_meansOutput].push_back(feature);
c@41 537
c@44 538 sprintf(labelBuffer, "Variances for channel %d", i+1);
c@44 539 feature.label = labelBuffer;
c@44 540
c@41 541 feature.values.clear();
c@42 542 for (int k = 0; k < m_featureColumnSize; ++k) {
c@41 543 feature.values.push_back(v[i][k]);
c@41 544 }
c@41 545
c@43 546 returnFeatures[m_variancesOutput].push_back(feature);
c@41 547
c@41 548 feature.values.clear();
c@41 549 for (int j = 0; j < m_channels; ++j) {
c@41 550 feature.values.push_back(distances[i][j]);
c@41 551 }
c@43 552
c@44 553 sprintf(labelBuffer, "Distances from channel %d", i+1);
c@44 554 feature.label = labelBuffer;
c@41 555
c@43 556 returnFeatures[m_distanceMatrixOutput].push_back(feature);
c@43 557
c@43 558 distanceVectorFeature.values.push_back(distances[0][i]);
c@44 559
c@44 560 sorted[distances[0][i]] = i;
c@41 561 }
c@41 562
c@43 563 returnFeatures[m_distanceVectorOutput].push_back(distanceVectorFeature);
c@43 564
c@44 565 feature.label = "Order of channels by similarity to first channel";
c@44 566 feature.values.clear();
c@44 567 feature.timestamp = Vamp::RealTime(0, 0);
c@44 568
c@44 569 for (std::map<double, int>::iterator i = sorted.begin();
c@44 570 i != sorted.end(); ++i) {
c@45 571 feature.values.push_back(i->second + 1);
c@44 572 }
c@44 573
c@44 574 returnFeatures[m_sortedVectorOutput].push_back(feature);
c@44 575
c@44 576 feature.label = "Ordered distances of channels from first channel";
c@44 577 feature.values.clear();
c@44 578 feature.timestamp = Vamp::RealTime(1, 0);
c@44 579
c@44 580 for (std::map<double, int>::iterator i = sorted.begin();
c@44 581 i != sorted.end(); ++i) {
c@44 582 feature.values.push_back(i->first);
c@44 583 }
c@44 584
c@44 585 returnFeatures[m_sortedVectorOutput].push_back(feature);
c@44 586
c@41 587 return returnFeatures;
c@41 588 }