annotate CepstrumPitchTracker.cpp @ 11:0c95dc49163a track

Some work on accepting/rejecting peaks

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
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#include "CepstrumPitchTracker.h"

#include <vector>
#include <algorithm>

#include <cstdio>
#include <cmath>
#include <complex>

using std::string;

CepstrumPitchTracker::CepstrumPitchTracker(float inputSampleRate) :
    Plugin(inputSampleRate),
    m_channels(0),
    m_stepSize(256),
    m_blockSize(1024),
    m_fmin(50),
    m_fmax(1000),
    m_histlen(1),
    m_vflen(3),
    m_binFrom(0),
    m_binTo(0),
    m_bins(0),
    m_history(0),
    m_prevpeak(0),
    m_prevprop(0)
{
}

CepstrumPitchTracker::~CepstrumPitchTracker()
{
    if (m_history) {
        for (int i = 0; i < m_histlen; ++i) {
            delete[] m_history[i];
        }
        delete[] m_history;
    }
}

string
CepstrumPitchTracker::getIdentifier() const
{
    return "cepstrum-pitch";
}

string
CepstrumPitchTracker::getName() const
{
    return "Cepstrum Pitch Tracker";
}

string
CepstrumPitchTracker::getDescription() const
{
    return "Estimate f0 of monophonic material using a cepstrum method.";
}

string
CepstrumPitchTracker::getMaker() const
{
    return "Chris Cannam";
}

int
CepstrumPitchTracker::getPluginVersion() const
{
    // Increment this each time you release a version that behaves
    // differently from the previous one
    return 1;
}

string
CepstrumPitchTracker::getCopyright() const
{
    return "Freely redistributable (BSD license)";
}

CepstrumPitchTracker::InputDomain
CepstrumPitchTracker::getInputDomain() const
{
    return FrequencyDomain;
}

size_t
CepstrumPitchTracker::getPreferredBlockSize() const
{
    return 1024;
}

size_t 
CepstrumPitchTracker::getPreferredStepSize() const
{
    return 256;
}

size_t
CepstrumPitchTracker::getMinChannelCount() const
{
    return 1;
}

size_t
CepstrumPitchTracker::getMaxChannelCount() const
{
    return 1;
}

CepstrumPitchTracker::ParameterList
CepstrumPitchTracker::getParameterDescriptors() const
{
    ParameterList list;
    return list;
}

float
CepstrumPitchTracker::getParameter(string identifier) const
{
    return 0.f;
}

void
CepstrumPitchTracker::setParameter(string identifier, float value) 
{
}

CepstrumPitchTracker::ProgramList
CepstrumPitchTracker::getPrograms() const
{
    ProgramList list;
    return list;
}

string
CepstrumPitchTracker::getCurrentProgram() const
{
    return ""; // no programs
}

void
CepstrumPitchTracker::selectProgram(string name)
{
}

CepstrumPitchTracker::OutputList
CepstrumPitchTracker::getOutputDescriptors() const
{
    OutputList outputs;

    int n = 0;

    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);

    return outputs;
}

bool
CepstrumPitchTracker::initialise(size_t channels, size_t stepSize, size_t blockSize)
{
    if (channels < getMinChannelCount() ||
	channels > getMaxChannelCount()) return false;

//    std::cerr << "CepstrumPitchTracker::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;
    }

    m_bins = (m_binTo - m_binFrom) + 1;

    m_history = new double *[m_histlen];
    for (int i = 0; i < m_histlen; ++i) {
        m_history[i] = new double[m_bins];
    }

    reset();

    return true;
}

void
CepstrumPitchTracker::reset()
{
    for (int i = 0; i < m_histlen; ++i) {
        for (int j = 0; j < m_bins; ++j) {
            m_history[i][j] = 0.0;
        }
    }
}

void
CepstrumPitchTracker::filter(const double *cep, double *result)
{
    int hix = m_histlen - 1; // current history index

    // roll back the history
    if (m_histlen > 1) {
        double *oldest = m_history[0];
        for (int i = 1; i < m_histlen; ++i) {
            m_history[i-1] = m_history[i];
        }
        // and stick this back in the newest spot, to recycle
        m_history[hix] = oldest;
    }

    for (int i = 0; i < m_bins; ++i) {
        double v = 0;
        int n = 0;
        // average according to the vertical filter length
        for (int j = -m_vflen/2; j <= m_vflen/2; ++j) {
            int ix = i + m_binFrom + j;
            if (ix >= 0 && ix < m_blockSize) {
                v += cep[ix];
                ++n;
            }
        }
        m_history[hix][i] = v / n;
    }

    for (int i = 0; i < m_bins; ++i) {
        double mean = 0.0;
        for (int j = 0; j < m_histlen; ++j) {
            mean += m_history[j][i];
        }
        mean /= m_histlen;
        result[i] = mean;
    }
}

double
CepstrumPitchTracker::calculatePeakProportion(const double *data, double abstot, int n)
{
    double aroundPeak = data[n];
    double peakProportion = 0.0;

    int i = n - 1;
    while (i > 0 && data[i] <= data[i+1]) {
        aroundPeak += fabs(data[i]);
        --i;
    }
    i = n + 1;
    while (i < m_bins && data[i] <= data[i-1]) {
        aroundPeak += fabs(data[i]);
        ++i;
    }
    peakProportion = aroundPeak / abstot;

    return peakProportion;
}

bool
CepstrumPitchTracker::acceptPeak(int n, double peakProportion)
{
    bool accept = false;

    if (abs(n - m_prevpeak) < 10) { //!!! should depend on bin count
        accept = true;
    } else if (peakProportion > m_prevprop * 2) {
        accept = true;
    }

    return accept;
}

CepstrumPitchTracker::FeatureSet
CepstrumPitchTracker::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
{
    FeatureSet fs;

    int bs = m_blockSize;
    int hs = m_blockSize/2 + 1;

    double *rawcep = new double[bs];
    double *io = new double[bs];
    double *logmag = new double[bs];

    // The "inverse symmetric" method. Seems to be the most reliable
        
    for (int i = 0; i < hs; ++i) {

	double power =
	    inputBuffers[0][i*2  ] * inputBuffers[0][i*2  ] +
	    inputBuffers[0][i*2+1] * inputBuffers[0][i*2+1];
	double mag = sqrt(power);
	
	double lm = log(mag + 0.00000001);
	
	logmag[i] = lm;
	if (i > 0) logmag[bs - i] = lm;
    }

    fft(bs, true, logmag, 0, rawcep, io);
    
    delete[] logmag;
    delete[] io;

    int n = m_bins;
    double *data = new double[n];
    filter(rawcep, data);
    delete[] rawcep;

    double abstot = 0.0;

    for (int i = 0; i < n; ++i) {
	abstot += fabs(data[i]);
    }

    double maxval = 0.0;
    int maxbin = -1;

    for (int i = 0; i < n; ++i) {
        if (data[i] > maxval) {
            maxval = data[i];
            maxbin = i;
        }
    }

    bool accepted = false;

    if (maxbin >= 0) {
        double pp = calculatePeakProportion(data, abstot, maxbin);
        if (acceptPeak(maxbin, pp)) {
            accepted = true;
        } else {
            // try a secondary peak
            maxval = 0.0;
            int secondbin = 0;
            for (int i = 1; i < n-1; ++i) {
                if (i != maxbin &&
                    data[i] > data[i-1] &&
                    data[i] > data[i+1] &&
                    data[i] > maxval) {
                    maxval = data[i];
                    secondbin = i;
                }
            }
            double spp = calculatePeakProportion(data, abstot, secondbin);
            if (acceptPeak(secondbin, spp)) {
                maxbin = secondbin;
                pp = spp;
                accepted = true;
            }
        }
        if (accepted) {
            m_prevpeak = maxbin;
            m_prevprop = pp;
        }
    }
            
//    std::cerr << "peakProportion = " << peakProportion << std::endl;
//    std::cerr << "peak = " << m_inputSampleRate / (maxbin + m_binFrom) << std::endl;
//    std::cerr << "bins = " << m_bins << std::endl;

//    if (peakProportion >= (0.00006 * m_bins)) {
    if (accepted) {
	Feature f;
	f.hasTimestamp = true;
	f.timestamp = timestamp;
	f.values.push_back(m_inputSampleRate / (maxbin + m_binFrom));
	fs[0].push_back(f);
    }

    delete[] data;
    return fs;
}

CepstrumPitchTracker::FeatureSet
CepstrumPitchTracker::getRemainingFeatures()
{
    FeatureSet fs;
    return fs;
}

void
CepstrumPitchTracker::fft(unsigned int n, bool inverse,
                    double *ri, double *ii, double *ro, double *io)
{
    if (!ri || !ro || !io) return;

    unsigned int bits;
    unsigned int i, j, k, m;
    unsigned int blockSize, blockEnd;

    double tr, ti;

    if (n < 2) return;
    if (n & (n-1)) return;

    double angle = 2.0 * M_PI;
    if (inverse) angle = -angle;

    for (i = 0; ; ++i) {
	if (n & (1 << i)) {
	    bits = i;
	    break;
	}
    }

    static unsigned int tableSize = 0;
    static int *table = 0;

    if (tableSize != n) {

	delete[] table;

	table = new int[n];

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

	    for (j = k = 0; j < bits; ++j) {
		k = (k << 1) | (m & 1);
		m >>= 1;
	    }

	    table[i] = k;
	}

	tableSize = n;
    }

    if (ii) {
	for (i = 0; i < n; ++i) {
	    ro[table[i]] = ri[i];
	    io[table[i]] = ii[i];
	}
    } else {
	for (i = 0; i < n; ++i) {
	    ro[table[i]] = ri[i];
	    io[table[i]] = 0.0;
	}
    }

    blockEnd = 1;

    for (blockSize = 2; blockSize <= n; blockSize <<= 1) {

	double delta = angle / (double)blockSize;
	double sm2 = -sin(-2 * delta);
	double sm1 = -sin(-delta);
	double cm2 = cos(-2 * delta);
	double cm1 = cos(-delta);
	double w = 2 * cm1;
	double ar[3], ai[3];

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

	    ar[2] = cm2;
	    ar[1] = cm1;

	    ai[2] = sm2;
	    ai[1] = sm1;

	    for (j = i, m = 0; m < blockEnd; j++, m++) {

		ar[0] = w * ar[1] - ar[2];
		ar[2] = ar[1];
		ar[1] = ar[0];

		ai[0] = w * ai[1] - ai[2];
		ai[2] = ai[1];
		ai[1] = ai[0];

		k = j + blockEnd;
		tr = ar[0] * ro[k] - ai[0] * io[k];
		ti = ar[0] * io[k] + ai[0] * ro[k];

		ro[k] = ro[j] - tr;
		io[k] = io[j] - ti;

		ro[j] += tr;
		io[j] += ti;
	    }
	}

	blockEnd = blockSize;
    }
}