annotate dsp/segmentation/ClusterMeltSegmenter.cpp @ 73:dcb555b90924

* Key detector: when returning key strengths, use the peak value of the
  three underlying chromagram correlations (from 36-bin chromagram)
  corresponding to each key, instead of the mean.
  Rationale: This is the same method as used when returning the key value,
  and it's nice to have the same results in both returned value and plot.
  The peak performed better than the sum with a simple test set of triads,
  so it seems reasonable to change the plot to match the key output rather
  than the other way around.

* FFT: kiss_fftr returns only the non-conjugate bins, synthesise the rest
  rather than leaving them (perhaps dangerously) undefined.  Fixes an
  uninitialised data error in chromagram that could cause garbage results
  from key detector.

* Constant Q: remove precalculated values again, I reckon they're not
  proving such a good tradeoff.

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

/*
 * ClusterMeltSegmenter.cpp
 *
 * Created by Mark Levy on 23/03/2006.
 * Copyright 2006 Centre for Digital Music, Queen Mary, University of London.
 * All rights reserved.
 */

#include <cfloat>
#include <cmath>

#include "ClusterMeltSegmenter.h"
#include "cluster_segmenter.h"
#include "segment.h"

#include "dsp/transforms/FFT.h"
#include "dsp/chromagram/ConstantQ.h"
#include "dsp/rateconversion/Decimator.h"
#include "dsp/mfcc/MFCC.h"

ClusterMeltSegmenter::ClusterMeltSegmenter(ClusterMeltSegmenterParams params) :
    window(NULL),
    fft(NULL),
    constq(NULL),
    mfcc(NULL),
    featureType(params.featureType),
    hopSize(params.hopSize),
    windowSize(params.windowSize),
    fmin(params.fmin),
    fmax(params.fmax),
    nbins(params.nbins),
    ncomponents(params.ncomponents),	// NB currently not passed - no. of PCA components is set in cluser_segmenter.c
    nHMMStates(params.nHMMStates),
    nclusters(params.nclusters),
    histogramLength(params.histogramLength),
    neighbourhoodLimit(params.neighbourhoodLimit),
    decimator(NULL)
{
}

void ClusterMeltSegmenter::initialise(int fs)
{
    samplerate = fs;

    if (featureType == FEATURE_TYPE_CONSTQ ||
        featureType == FEATURE_TYPE_CHROMA) {
        
        // run internal processing at 11025 or thereabouts
        int internalRate = 11025;
        int decimationFactor = samplerate / internalRate;
        if (decimationFactor < 1) decimationFactor = 1;

        // must be a power of two
        while (decimationFactor & (decimationFactor - 1)) ++decimationFactor;

        if (decimationFactor > Decimator::getHighestSupportedFactor()) {
            decimationFactor = Decimator::getHighestSupportedFactor();
        }

        if (decimationFactor > 1) {
            decimator = new Decimator(getWindowsize(), decimationFactor);
        }

        CQConfig config;
        config.FS = samplerate / decimationFactor;
        config.min = fmin;
        config.max = fmax;
        config.BPO = nbins;
        config.CQThresh = 0.0054;

        constq = new ConstantQ(config);
        constq->sparsekernel();
        
        ncoeff = constq->getK();

        fft = new FFTReal(constq->getfftlength());
        
    } else if (featureType == FEATURE_TYPE_MFCC) {

        // run internal processing at 22050 or thereabouts
        int internalRate = 22050;
        int decimationFactor = samplerate / internalRate;
        if (decimationFactor < 1) decimationFactor = 1;

        // must be a power of two
        while (decimationFactor & (decimationFactor - 1)) ++decimationFactor;

        if (decimationFactor > Decimator::getHighestSupportedFactor()) {
            decimationFactor = Decimator::getHighestSupportedFactor();
        }

        if (decimationFactor > 1) {
            decimator = new Decimator(getWindowsize(), decimationFactor);
        }

        MFCCConfig config(samplerate / decimationFactor);
        config.fftsize = 2048;
        config.nceps = 19;
        config.want_c0 = true;

        mfcc = new MFCC(config);
        ncoeff = config.nceps + 1;
    }
}

ClusterMeltSegmenter::~ClusterMeltSegmenter() 
{
    delete window;
    delete constq;
    delete decimator;
    delete fft;
}

int
ClusterMeltSegmenter::getWindowsize()
{
    return static_cast<int>(windowSize * samplerate + 0.001);
}

int
ClusterMeltSegmenter::getHopsize()
{
    return static_cast<int>(hopSize * samplerate + 0.001);
}

void ClusterMeltSegmenter::extractFeatures(const double* samples, int nsamples)
{
    if (featureType == FEATURE_TYPE_CONSTQ ||
        featureType == FEATURE_TYPE_CHROMA) {
        extractFeaturesConstQ(samples, nsamples);
    } else if (featureType == FEATURE_TYPE_MFCC) {
        extractFeaturesMFCC(samples, nsamples);
    }
}

void ClusterMeltSegmenter::extractFeaturesConstQ(const double* samples, int nsamples)
{
    if (!constq) {
        std::cerr << "ERROR: ClusterMeltSegmenter::extractFeaturesConstQ: "
                  << "No const-q: initialise not called?"
                  << std::endl;
        return;
    }

    if (nsamples < getWindowsize()) {
        std::cerr << "ERROR: ClusterMeltSegmenter::extractFeatures: nsamples < windowsize (" << nsamples << " < " << getWindowsize() << ")" << std::endl;
        return;
    }

    int fftsize = constq->getfftlength();

    if (!window || window->getSize() != fftsize) {
        delete window;
        window = new Window<double>(HammingWindow, fftsize);
    }

    vector<double> cq(ncoeff);

    for (int i = 0; i < ncoeff; ++i) cq[i] = 0.0;
    
    const double *psource = samples;
    int pcount = nsamples;

    if (decimator) {
        pcount = nsamples / decimator->getFactor();
        double *decout = new double[pcount];
        decimator->process(samples, decout);
        psource = decout;
    }
    
    int origin = 0;
    
//    std::cerr << "nsamples = " << nsamples << ", pcount = " << pcount << std::endl;

    int frames = 0;

    double *frame = new double[fftsize];
    double *real = new double[fftsize];
    double *imag = new double[fftsize];
    double *cqre = new double[ncoeff];
    double *cqim = new double[ncoeff];

    while (origin <= pcount) {

        // always need at least one fft window per block, but after
        // that we want to avoid having any incomplete ones
        if (origin > 0 && origin + fftsize >= pcount) break;

        for (int i = 0; i < fftsize; ++i) {
            if (origin + i < pcount) {
                frame[i] = psource[origin + i];
            } else {
                frame[i] = 0.0;
            }
        }

        for (int i = 0; i < fftsize/2; ++i) {
            double value = frame[i];
            frame[i] = frame[i + fftsize/2];
            frame[i + fftsize/2] = value;
        }

        window->cut(frame);
        
        fft->process(false, frame, real, imag);
        
        constq->process(real, imag, cqre, cqim);
	
        for (int i = 0; i < ncoeff; ++i) {
            cq[i] += sqrt(cqre[i] * cqre[i] + cqim[i] * cqim[i]);
        }
        ++frames;

        origin += fftsize/2;
    }

    delete [] cqre;
    delete [] cqim;
    delete [] real;
    delete [] imag;
    delete [] frame;

    for (int i = 0; i < ncoeff; ++i) {
        cq[i] /= frames;
    }

    if (decimator) delete[] psource;

    features.push_back(cq);
}

void ClusterMeltSegmenter::extractFeaturesMFCC(const double* samples, int nsamples)
{
    if (!mfcc) {
        std::cerr << "ERROR: ClusterMeltSegmenter::extractFeaturesMFCC: "
                  << "No mfcc: initialise not called?"
                  << std::endl;
        return;
    }

    if (nsamples < getWindowsize()) {
        std::cerr << "ERROR: ClusterMeltSegmenter::extractFeatures: nsamples < windowsize (" << nsamples << " < " << getWindowsize() << ")" << std::endl;
        return;
    }

    int fftsize = mfcc->getfftlength();

    vector<double> cc(ncoeff);

    for (int i = 0; i < ncoeff; ++i) cc[i] = 0.0;
    
    const double *psource = samples;
    int pcount = nsamples;

    if (decimator) {
        pcount = nsamples / decimator->getFactor();
        double *decout = new double[pcount];
        decimator->process(samples, decout);
        psource = decout;
    }

    int origin = 0;
    int frames = 0;

    double *frame = new double[fftsize];
    double *ccout = new double[ncoeff];

    while (origin <= pcount) {

        // always need at least one fft window per block, but after
        // that we want to avoid having any incomplete ones
        if (origin > 0 && origin + fftsize >= pcount) break;

        for (int i = 0; i < fftsize; ++i) {
            if (origin + i < pcount) {
                frame[i] = psource[origin + i];
            } else {
                frame[i] = 0.0;
            }
        }

        mfcc->process(frame, ccout);
	
        for (int i = 0; i < ncoeff; ++i) {
            cc[i] += ccout[i];
        }
        ++frames;

        origin += fftsize/2;
    }

    delete [] ccout;
    delete [] frame;

    for (int i = 0; i < ncoeff; ++i) {
        cc[i] /= frames;
    }

    if (decimator) delete[] psource;

    features.push_back(cc);
}

void ClusterMeltSegmenter::segment(int m)
{
    nclusters = m;
    segment();
}

void ClusterMeltSegmenter::setFeatures(const vector<vector<double> >& f)
{
    features = f;
    featureType = FEATURE_TYPE_UNKNOWN;
}

void ClusterMeltSegmenter::segment()
{
    delete constq;
    constq = 0;
    delete mfcc;
    mfcc = 0;
    delete decimator;
    decimator = 0;

    if (features.size() < histogramLength) return;
/*    
    std::cerr << "ClusterMeltSegmenter::segment: have " << features.size()
              << " features with " << features[0].size() << " coefficients (ncoeff = " << ncoeff << ", ncomponents = " << ncomponents << ")" << std::endl;
*/
    // copy the features to a native array and use the existing C segmenter...
    double** arrFeatures = new double*[features.size()];	
    for (int i = 0; i < features.size(); i++)
    {
        if (featureType == FEATURE_TYPE_UNKNOWN) {
            arrFeatures[i] = new double[features[0].size()];
            for (int j = 0; j < features[0].size(); j++)
                arrFeatures[i][j] = features[i][j];	
        } else {
            arrFeatures[i] = new double[ncoeff+1];	// allow space for the normalised envelope
            for (int j = 0; j < ncoeff; j++)
                arrFeatures[i][j] = features[i][j];	
        }
    }
	
    q = new int[features.size()];
	
    if (featureType == FEATURE_TYPE_UNKNOWN ||
        featureType == FEATURE_TYPE_MFCC)
        cluster_segment(q, arrFeatures, features.size(), features[0].size(), nHMMStates, histogramLength, 
                        nclusters, neighbourhoodLimit);
    else
        constq_segment(q, arrFeatures, features.size(), nbins, ncoeff, featureType, 
                       nHMMStates, histogramLength, nclusters, neighbourhoodLimit);
	
    // convert the cluster assignment sequence to a segmentation
    makeSegmentation(q, features.size());		
	
    // de-allocate arrays
    delete [] q;
    for (int i = 0; i < features.size(); i++)
        delete [] arrFeatures[i];
    delete [] arrFeatures;
	
    // clear the features
    clear();
}

void ClusterMeltSegmenter::makeSegmentation(int* q, int len)
{
    segmentation.segments.clear();
    segmentation.nsegtypes = nclusters;
    segmentation.samplerate = samplerate;
	
    Segment segment;
    segment.start = 0;
    segment.type = q[0];
	
    for (int i = 1; i < len; i++)
    {
        if (q[i] != q[i-1])
        {
            segment.end = i * getHopsize();
            segmentation.segments.push_back(segment);
            segment.type = q[i];
            segment.start = segment.end;
        }
    }
    segment.end = len * getHopsize();
    segmentation.segments.push_back(segment);
}