Mercurial > hg > svcore
view data/model/FFTModel.cpp @ 1406:09751743647e
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author | Chris Cannam |
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date | Tue, 07 Mar 2017 13:52:37 +0000 |
parents | fad8f533ca13 |
children | 87ae75da6527 |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "FFTModel.h" #include "DenseTimeValueModel.h" #include "base/Profiler.h" #include "base/Pitch.h" #include "base/HitCount.h" #include <algorithm> #include <cassert> #include <deque> using namespace std; static HitCount inSmallCache("FFTModel: Small FFT cache"); static HitCount inSourceCache("FFTModel: Source data cache"); FFTModel::FFTModel(const DenseTimeValueModel *model, int channel, WindowType windowType, int windowSize, int windowIncrement, int fftSize) : m_model(model), m_channel(channel), m_windowType(windowType), m_windowSize(windowSize), m_windowIncrement(windowIncrement), m_fftSize(fftSize), m_windower(windowType, windowSize), m_fft(fftSize), m_cacheWriteIndex(0), m_cacheSize(3) { while (m_cached.size() < m_cacheSize) { m_cached.push_back({ -1, cvec(m_fftSize / 2 + 1) }); } if (m_windowSize > m_fftSize) { cerr << "ERROR: FFTModel::FFTModel: window size (" << m_windowSize << ") must be at least FFT size (" << m_fftSize << ")" << endl; throw invalid_argument("FFTModel window size must be at least FFT size"); } m_fft.initFloat(); connect(model, SIGNAL(modelChanged()), this, SIGNAL(modelChanged())); connect(model, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t)), this, SIGNAL(modelChangedWithin(sv_frame_t, sv_frame_t))); } FFTModel::~FFTModel() { } void FFTModel::sourceModelAboutToBeDeleted() { if (m_model) { cerr << "FFTModel[" << this << "]::sourceModelAboutToBeDeleted(" << m_model << ")" << endl; m_model = 0; } } int FFTModel::getWidth() const { if (!m_model) return 0; return int((m_model->getEndFrame() - m_model->getStartFrame()) / m_windowIncrement) + 1; } int FFTModel::getHeight() const { return m_fftSize / 2 + 1; } QString FFTModel::getBinName(int n) const { sv_samplerate_t sr = getSampleRate(); if (!sr) return ""; QString name = tr("%1 Hz").arg((n * sr) / ((getHeight()-1) * 2)); return name; } FFTModel::Column FFTModel::getColumn(int x) const { auto cplx = getFFTColumn(x); Column col; col.reserve(cplx.size()); for (auto c: cplx) col.push_back(abs(c)); return col; } FFTModel::Column FFTModel::getPhases(int x) const { auto cplx = getFFTColumn(x); Column col; col.reserve(cplx.size()); for (auto c: cplx) { col.push_back(arg(c)); } return col; } float FFTModel::getMagnitudeAt(int x, int y) const { if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f; auto col = getFFTColumn(x); return abs(col[y]); } float FFTModel::getMaximumMagnitudeAt(int x) const { Column col(getColumn(x)); float max = 0.f; int n = int(col.size()); for (int i = 0; i < n; ++i) { if (col[i] > max) max = col[i]; } return max; } float FFTModel::getPhaseAt(int x, int y) const { if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) return 0.f; return arg(getFFTColumn(x)[y]); } void FFTModel::getValuesAt(int x, int y, float &re, float &im) const { auto col = getFFTColumn(x); re = col[y].real(); im = col[y].imag(); } bool FFTModel::getMagnitudesAt(int x, float *values, int minbin, int count) const { if (count == 0) count = getHeight(); auto col = getFFTColumn(x); for (int i = 0; i < count; ++i) { values[i] = abs(col[minbin + i]); } return true; } bool FFTModel::getPhasesAt(int x, float *values, int minbin, int count) const { if (count == 0) count = getHeight(); auto col = getFFTColumn(x); for (int i = 0; i < count; ++i) { values[i] = arg(col[minbin + i]); } return true; } bool FFTModel::getValuesAt(int x, float *reals, float *imags, int minbin, int count) const { if (count == 0) count = getHeight(); auto col = getFFTColumn(x); for (int i = 0; i < count; ++i) { reals[i] = col[minbin + i].real(); } for (int i = 0; i < count; ++i) { imags[i] = col[minbin + i].imag(); } return true; } FFTModel::fvec FFTModel::getSourceSamples(int column) const { // m_fftSize may be greater than m_windowSize, but not the reverse // cerr << "getSourceSamples(" << column << ")" << endl; auto range = getSourceSampleRange(column); auto data = getSourceData(range); int off = (m_fftSize - m_windowSize) / 2; if (off == 0) { return data; } else { vector<float> pad(off, 0.f); fvec padded; padded.reserve(m_fftSize); padded.insert(padded.end(), pad.begin(), pad.end()); padded.insert(padded.end(), data.begin(), data.end()); padded.insert(padded.end(), pad.begin(), pad.end()); return padded; } } FFTModel::fvec FFTModel::getSourceData(pair<sv_frame_t, sv_frame_t> range) const { // cerr << "getSourceData(" << range.first << "," << range.second // << "): saved range is (" << m_savedData.range.first // << "," << m_savedData.range.second << ")" << endl; if (m_savedData.range == range) { inSourceCache.hit(); return m_savedData.data; } Profiler profiler("FFTModel::getSourceData (cache miss)"); if (range.first < m_savedData.range.second && range.first >= m_savedData.range.first && range.second > m_savedData.range.second) { inSourceCache.partial(); sv_frame_t discard = range.first - m_savedData.range.first; fvec acc(m_savedData.data.begin() + discard, m_savedData.data.end()); fvec rest = getSourceDataUncached({ m_savedData.range.second, range.second }); acc.insert(acc.end(), rest.begin(), rest.end()); m_savedData = { range, acc }; return acc; } else { inSourceCache.miss(); auto data = getSourceDataUncached(range); m_savedData = { range, data }; return data; } } FFTModel::fvec FFTModel::getSourceDataUncached(pair<sv_frame_t, sv_frame_t> range) const { decltype(range.first) pfx = 0; if (range.first < 0) { pfx = -range.first; range = { 0, range.second }; } auto data = m_model->getData(m_channel, range.first, range.second - range.first); if (data.empty()) { SVDEBUG << "NOTE: empty source data for range (" << range.first << "," << range.second << ") (model end frame " << m_model->getEndFrame() << ")" << endl; } // don't return a partial frame data.resize(range.second - range.first, 0.f); if (pfx > 0) { vector<float> pad(pfx, 0.f); data.insert(data.begin(), pad.begin(), pad.end()); } if (m_channel == -1) { int channels = m_model->getChannelCount(); if (channels > 1) { int n = int(data.size()); float factor = 1.f / float(channels); // use mean instead of sum for fft model input for (int i = 0; i < n; ++i) { data[i] *= factor; } } } return data; } const FFTModel::cvec & FFTModel::getFFTColumn(int n) const { // The small cache (i.e. the m_cached deque) is for cases where // values are looked up individually, and for e.g. peak-frequency // spectrograms where values from two consecutive columns are // needed at once. This cache gets essentially no hits when // scrolling through a magnitude spectrogram, but 95%+ hits with a // peak-frequency spectrogram. for (const auto &incache : m_cached) { if (incache.n == n) { inSmallCache.hit(); return incache.col; } } inSmallCache.miss(); Profiler profiler("FFTModel::getFFTColumn (cache miss)"); auto samples = getSourceSamples(n); m_windower.cut(samples.data()); breakfastquay::v_fftshift(samples.data(), m_fftSize); cvec &col = m_cached[m_cacheWriteIndex].col; m_fft.forwardInterleaved(samples.data(), reinterpret_cast<float *>(col.data())); m_cached[m_cacheWriteIndex].n = n; m_cacheWriteIndex = (m_cacheWriteIndex + 1) % m_cacheSize; return col; } bool FFTModel::estimateStableFrequency(int x, int y, double &frequency) { if (!isOK()) return false; frequency = double(y * getSampleRate()) / m_fftSize; if (x+1 >= getWidth()) return false; // At frequency f, a phase shift of 2pi (one cycle) happens in 1/f sec. // At hopsize h and sample rate sr, one hop happens in h/sr sec. // At window size w, for bin b, f is b*sr/w. // thus 2pi phase shift happens in w/(b*sr) sec. // We need to know what phase shift we expect from h/sr sec. // -> 2pi * ((h/sr) / (w/(b*sr))) // = 2pi * ((h * b * sr) / (w * sr)) // = 2pi * (h * b) / w. double oldPhase = getPhaseAt(x, y); double newPhase = getPhaseAt(x+1, y); int incr = getResolution(); double expectedPhase = oldPhase + (2.0 * M_PI * y * incr) / m_fftSize; double phaseError = princarg(newPhase - expectedPhase); // The new frequency estimate based on the phase error resulting // from assuming the "native" frequency of this bin frequency = (getSampleRate() * (expectedPhase + phaseError - oldPhase)) / (2.0 * M_PI * incr); return true; } FFTModel::PeakLocationSet FFTModel::getPeaks(PeakPickType type, int x, int ymin, int ymax) const { Profiler profiler("FFTModel::getPeaks"); FFTModel::PeakLocationSet peaks; if (!isOK()) return peaks; if (ymax == 0 || ymax > getHeight() - 1) { ymax = getHeight() - 1; } if (type == AllPeaks) { int minbin = ymin; if (minbin > 0) minbin = minbin - 1; int maxbin = ymax; if (maxbin < getHeight() - 1) maxbin = maxbin + 1; const int n = maxbin - minbin + 1; float *values = new float[n]; getMagnitudesAt(x, values, minbin, maxbin - minbin + 1); for (int bin = ymin; bin <= ymax; ++bin) { if (bin == minbin || bin == maxbin) continue; if (values[bin - minbin] > values[bin - minbin - 1] && values[bin - minbin] > values[bin - minbin + 1]) { peaks.insert(bin); } } delete[] values; return peaks; } Column values = getColumn(x); int nv = int(values.size()); float mean = 0.f; for (int i = 0; i < nv; ++i) mean += values[i]; if (nv > 0) mean = mean / float(values.size()); // For peak picking we use a moving median window, picking the // highest value within each continuous region of values that // exceed the median. For pitch adaptivity, we adjust the window // size to a roughly constant pitch range (about four tones). sv_samplerate_t sampleRate = getSampleRate(); deque<float> window; vector<int> inrange; float dist = 0.5; int medianWinSize = getPeakPickWindowSize(type, sampleRate, ymin, dist); int halfWin = medianWinSize/2; int binmin; if (ymin > halfWin) binmin = ymin - halfWin; else binmin = 0; int binmax; if (ymax + halfWin < nv) binmax = ymax + halfWin; else binmax = nv - 1; int prevcentre = 0; for (int bin = binmin; bin <= binmax; ++bin) { float value = values[bin]; window.push_back(value); // so-called median will actually be the dist*100'th percentile medianWinSize = getPeakPickWindowSize(type, sampleRate, bin, dist); halfWin = medianWinSize/2; while ((int)window.size() > medianWinSize) { window.pop_front(); } int actualSize = int(window.size()); if (type == MajorPitchAdaptivePeaks) { if (ymax + halfWin < nv) binmax = ymax + halfWin; else binmax = nv - 1; } deque<float> sorted(window); sort(sorted.begin(), sorted.end()); float median = sorted[int(float(sorted.size()) * dist)]; int centrebin = 0; if (bin > actualSize/2) centrebin = bin - actualSize/2; while (centrebin > prevcentre || bin == binmin) { if (centrebin > prevcentre) ++prevcentre; float centre = values[prevcentre]; if (centre > median) { inrange.push_back(centrebin); } if (centre <= median || centrebin+1 == nv) { if (!inrange.empty()) { int peakbin = 0; float peakval = 0.f; for (int i = 0; i < (int)inrange.size(); ++i) { if (i == 0 || values[inrange[i]] > peakval) { peakval = values[inrange[i]]; peakbin = inrange[i]; } } inrange.clear(); if (peakbin >= ymin && peakbin <= ymax) { peaks.insert(peakbin); } } } if (bin == binmin) break; } } return peaks; } int FFTModel::getPeakPickWindowSize(PeakPickType type, sv_samplerate_t sampleRate, int bin, float &percentile) const { percentile = 0.5; if (type == MajorPeaks) return 10; if (bin == 0) return 3; double binfreq = (sampleRate * bin) / m_fftSize; double hifreq = Pitch::getFrequencyForPitch(73, 0, binfreq); int hibin = int(lrint((hifreq * m_fftSize) / sampleRate)); int medianWinSize = hibin - bin; if (medianWinSize < 3) medianWinSize = 3; percentile = 0.5f + float(binfreq / sampleRate); return medianWinSize; } FFTModel::PeakSet FFTModel::getPeakFrequencies(PeakPickType type, int x, int ymin, int ymax) const { Profiler profiler("FFTModel::getPeakFrequencies"); PeakSet peaks; if (!isOK()) return peaks; PeakLocationSet locations = getPeaks(type, x, ymin, ymax); sv_samplerate_t sampleRate = getSampleRate(); int incr = getResolution(); // This duplicates some of the work of estimateStableFrequency to // allow us to retrieve the phases in two separate vertical // columns, instead of jumping back and forth between columns x and // x+1, which may be significantly slower if re-seeking is needed vector<float> phases; for (PeakLocationSet::iterator i = locations.begin(); i != locations.end(); ++i) { phases.push_back(getPhaseAt(x, *i)); } int phaseIndex = 0; for (PeakLocationSet::iterator i = locations.begin(); i != locations.end(); ++i) { double oldPhase = phases[phaseIndex]; double newPhase = getPhaseAt(x+1, *i); double expectedPhase = oldPhase + (2.0 * M_PI * *i * incr) / m_fftSize; double phaseError = princarg(newPhase - expectedPhase); double frequency = (sampleRate * (expectedPhase + phaseError - oldPhase)) / (2 * M_PI * incr); peaks[*i] = frequency; ++phaseIndex; } return peaks; }