Cepstral Pitch Tracker

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*

    This file is Copyright (c) 2012 Chris Cannam

    Permission is hereby granted, free of charge, to any person

    obtaining a copy of this software and associated documentation

    files (the "Software"), to deal in the Software without

    restriction, including without limitation the rights to use, copy,

    modify, merge, publish, distribute, sublicense, and/or sell copies

    of the Software, and to permit persons to whom the Software is

    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be

    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR

    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION

    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*/

#include "CepstralPitchTracker.h"

#include "Cepstrum.h"

#include "MeanFilter.h"

#include "PeakInterpolator.h"

#include "AgentFeeder.h"

#include "vamp-sdk/FFT.h"

#include <vector>

#include <algorithm>

#include <cstdio>

#include <cmath>

#include <complex>

using std::string;

using std::vector;

using Vamp::RealTime;

CepstralPitchTracker::CepstralPitchTracker(float inputSampleRate) :

    Plugin(inputSampleRate),

    m_channels(0),

    m_stepSize(256),

    m_blockSize(1024),

    m_fmin(50),

    m_fmax(900),

    m_vflen(1),

    m_slack(40),

    m_sensitivity(10),

    m_threshold(0.1),

    m_fillGaps(false),

    m_binFrom(0),

    m_binTo(0),

    m_bins(0),

    m_nAccepted(0),

    m_feeder(0)

{

}

CepstralPitchTracker::~CepstralPitchTracker()

{

    delete m_feeder;

}

string

CepstralPitchTracker::getIdentifier() const

{

    return "cepstral-pitchtracker";

}

string

CepstralPitchTracker::getName() const

{

    return "Cepstral Pitch Tracker";

}

string

CepstralPitchTracker::getDescription() const

{

    return "Estimate f0 of monophonic material using a cepstrum method.";

}

string

CepstralPitchTracker::getMaker() const

{

    return "Chris Cannam";

}

int

CepstralPitchTracker::getPluginVersion() const

{

    // Increment this each time you release a version that behaves

    // differently from the previous one

    return 2;

}

string

CepstralPitchTracker::getCopyright() const

{

    return "Freely redistributable (BSD license)";

}

CepstralPitchTracker::InputDomain

CepstralPitchTracker::getInputDomain() const

{

    return FrequencyDomain;

}

size_t

CepstralPitchTracker::getPreferredBlockSize() const

{

    return 1024;

}

size_t

CepstralPitchTracker::getPreferredStepSize() const

{

    return 256;

}

size_t

CepstralPitchTracker::getMinChannelCount() const

{

    return 1;

}

size_t

CepstralPitchTracker::getMaxChannelCount() const

{

    return 1;

}

CepstralPitchTracker::ParameterList

CepstralPitchTracker::getParameterDescriptors() const

{

    ParameterList list;

    ParameterDescriptor d;

    d.identifier = "sensitivity";

    d.name = "Sensitivity";

    d.description = "Sensitivity of the voicing detector";

    d.unit = "";

    d.minValue = 0;

    d.maxValue = 100;

    d.defaultValue = 10;

    d.isQuantized = true;

    d.quantizeStep = 1;

    list.push_back(d);

    d.identifier = "slack";

    d.name = "Slack";

    d.description = "Maximum permissible length of voicing gap for a continuous note";

    d.unit = "ms";

    d.minValue = 0;

    d.maxValue = 200;

    d.defaultValue = 40;

    d.isQuantized = true;

    d.quantizeStep = 1;

    list.push_back(d);

    d.identifier = "threshold";

    d.name = "Silence threshold";

    d.description = "Threshold for silence detection";

    d.unit = ""; //!!! todo: convert this threshold to a meaningful unit!

    d.minValue = 0;

    d.maxValue = 0.5;

    d.defaultValue = 0.1;

    d.isQuantized = false;

    list.push_back(d);

    d.identifier = "fill";

    d.name = "Fill f0 gaps within a note";

    d.description = "Return an f0 value for every frame within each discovered note, interpolating results into any gaps in the measurement";

    d.unit = ""; //!!! todo: convert this threshold to a meaningful unit!

    d.minValue = 0;

    d.maxValue = 1;

    d.defaultValue = 0;

    d.isQuantized = true;

    d.quantizeStep = 1;

    list.push_back(d);

    return list;

}

float

CepstralPitchTracker::getParameter(string identifier) const

{

    if (identifier == "sensitivity") return m_sensitivity;

    else if (identifier == "slack") return m_slack;

    else if (identifier == "threshold") return m_threshold;

    else if (identifier == "fill") return (m_fillGaps ? 1 : 0);

    return 0.f;

}

void

CepstralPitchTracker::setParameter(string identifier, float value)

{

    if (identifier == "sensitivity") m_sensitivity = value;

    else if (identifier == "slack") m_slack = value;

    else if (identifier == "threshold") m_threshold = value;

    else if (identifier == "fill") m_fillGaps = (value > 0.5);

}

CepstralPitchTracker::ProgramList

CepstralPitchTracker::getPrograms() const

{

    ProgramList list;

    return list;

}

string

CepstralPitchTracker::getCurrentProgram() const

{

    return ""; // no programs

}

void

CepstralPitchTracker::selectProgram(string name)

{

}

CepstralPitchTracker::OutputList

CepstralPitchTracker::getOutputDescriptors() const

{

    OutputList outputs;

    OutputDescriptor d;

    d.identifier = "f0";

    d.name = "Estimated f0";

    d.description = "Estimated fundamental frequency";

    d.unit = "Hz";

    d.hasFixedBinCount = true;

    d.binCount = 1;

    d.hasKnownExtents = true;

    d.minValue = m_fmin;

    d.maxValue = m_fmax;

    d.isQuantized = false;

    d.sampleType = OutputDescriptor::FixedSampleRate;

    d.sampleRate = (m_inputSampleRate / m_stepSize);

    d.hasDuration = false;

    outputs.push_back(d);

    d.identifier = "notes";

    d.name = "Notes";

    d.description = "Derived fixed-pitch note frequencies";

    d.unit = "Hz";

    d.hasFixedBinCount = true;

    d.binCount = 1;

    d.hasKnownExtents = true;

    d.minValue = m_fmin;

    d.maxValue = m_fmax;

    d.isQuantized = false;

    d.sampleType = OutputDescriptor::FixedSampleRate;

    d.sampleRate = (m_inputSampleRate / m_stepSize);

    d.hasDuration = true;

    outputs.push_back(d);

    d.identifier = "raw";

    d.name = "Raw frequencies";

    d.description = "Raw peak frequencies from cepstrum, including unvoiced segments";

    d.unit = "Hz";

    d.hasFixedBinCount = true;

    d.binCount = 1;

    d.hasKnownExtents = true;

    d.minValue = m_fmin;

    d.maxValue = m_fmax;

    d.isQuantized = false;

    d.sampleType = OutputDescriptor::OneSamplePerStep;

    d.hasDuration = false;

    outputs.push_back(d);

    return outputs;

}

bool

CepstralPitchTracker::initialise(size_t channels, size_t stepSize, size_t blockSize)

{

    if (channels < getMinChannelCount() ||

        channels > getMaxChannelCount()) return false;

//    std::cerr << "CepstralPitchTracker::initialise: channels = " << channels

//              << ", stepSize = " << stepSize << ", blockSize = " << blockSize

//              << std::endl;

    m_channels = channels;

    m_stepSize = stepSize;

    m_blockSize = blockSize;

    m_binFrom = int(m_inputSampleRate / m_fmax);

    m_binTo = int(m_inputSampleRate / m_fmin);

    if (m_binTo >= (int)m_blockSize / 2) {

        m_binTo = m_blockSize / 2 - 1;

    }

    if (m_binFrom >= m_binTo) {

        // shouldn't happen except for degenerate samplerate / blocksize combos

        m_binFrom = m_binTo - 1;

    }

    m_bins = (m_binTo - m_binFrom) + 1;

    reset();

    return true;

}

void

CepstralPitchTracker::reset()

{

    delete m_feeder;

    m_feeder = new AgentFeeder(m_slack);

    m_nAccepted = 0;

}

void

CepstralPitchTracker::addFeaturesFrom(NoteHypothesis h, FeatureSet &fs)

{

    NoteHypothesis::Estimates es = h.getAcceptedEstimates();

    NoteHypothesis::Note n = h.getAveragedNote();

    if (!m_fillGaps) {

        for (int i = 0; i < (int)es.size(); ++i) {

            Feature f;

            f.hasTimestamp = true;

            f.timestamp = es[i].time;

            f.values.push_back(es[i].freq);

            fs[0].push_back(f);

        }

    } else {

        int ix = 0;

        RealTime increment = RealTime::frame2RealTime

            (m_stepSize, m_inputSampleRate);

        float freq = 0;

        for (RealTime t = n.time; t < n.time + n.duration; t = t + increment) {

            if (ix < (int)es.size() && t >= es[ix].time) {

                freq = es[ix].freq;

                ++ix;

            }

            if (freq > 0) {

                Feature f;

                f.hasTimestamp = true;

                f.timestamp = t;

                f.values.push_back(freq);

                fs[0].push_back(f);

            }

        }

    }

    Feature nf;

    nf.hasTimestamp = true;

    nf.hasDuration = true;

    nf.timestamp = n.time;

    nf.duration = n.duration;

    nf.values.push_back(n.freq);

    fs[1].push_back(nf);

}

void

CepstralPitchTracker::addNewFeatures(FeatureSet &fs)

{

    int n = m_feeder->getAcceptedHypotheses().size();

    if (n == m_nAccepted) return;

    AgentFeeder::Hypotheses accepted = m_feeder->getAcceptedHypotheses();

    for (int i = m_nAccepted; i < n; ++i) {

        addFeaturesFrom(accepted[i], fs);

    }

    m_nAccepted = n;

}

CepstralPitchTracker::FeatureSet

CepstralPitchTracker::process(const float *const *inputBuffers, RealTime timestamp)

{

    double *rawcep = new double[m_blockSize];

    double magmean = Cepstrum(m_blockSize).process(inputBuffers[0], rawcep);

    int n = m_bins;

    double *data = new double[n];

    MeanFilter(m_vflen).filterSubsequence

        (rawcep, data, m_blockSize, n, m_binFrom);

    delete[] rawcep;

    double maxval = 0.0;

    int maxbin = -1;

    for (int i = 0; i < n; ++i) {

        if (data[i] > maxval) {

            maxval = data[i];

            maxbin = i;

        }

    }

    if (maxbin < 0) {

        delete[] data;

        return FeatureSet();

    }

    double nextPeakVal = 0.0;

    for (int i = 1; i+1 < n; ++i) {

        if (data[i] > data[i-1] &&

            data[i] > data[i+1] &&

            i != maxbin &&

            data[i] > nextPeakVal) {

            nextPeakVal = data[i];

        }

    }

    PeakInterpolator pi;

    double cimax = pi.findPeakLocation(data, m_bins, maxbin);

    double peakfreq = m_inputSampleRate / (cimax + m_binFrom);

    FeatureSet fs;

    Feature rawf;

    rawf.hasTimestamp = false;

    rawf.hasDuration = false;

    rawf.values.push_back(peakfreq);

    fs[2].push_back(rawf);

    double confidence = 0.0;

    if (nextPeakVal != 0.0) {

        confidence = (maxval - nextPeakVal) * m_sensitivity;

        if (magmean < m_threshold) confidence = 0.0;

    }

    delete[] data;

    NoteHypothesis::Estimate e;

    e.freq = peakfreq;

    e.time = timestamp;

    e.confidence = confidence;

    m_feeder->feed(e);

    addNewFeatures(fs);

    return fs;

}

CepstralPitchTracker::FeatureSet

CepstralPitchTracker::getRemainingFeatures()

{

    m_feeder->finish();

    FeatureSet fs;

    addNewFeatures(fs);

    return fs;

}