ChordSegmentator.hxx

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/*
 * Copyright (c) 2001-2006 MUSIC TECHNOLOGY GROUP (MTG)
 *                         UNIVERSITAT POMPEU FABRA
 *
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifndef ChordSegmentator_hxx
#define ChordSegmentator_hxx

#include <iostream>
#include <fstream>
#include <cmath>
#include "Array.hxx"
#include "DiscontinuousSegmentation.hxx"
#include "ChordCorrelator.hxx"
#include "Assert.hxx"

namespace Simac
{

class ChordSegmentator
{
        CLAM::DiscontinuousSegmentation _segmentation;
        std::vector<unsigned> _chordIndexes;

        unsigned _currentSegment;
        bool _segmentOpen;
        unsigned _lastChord;

        unsigned _method;
        
        // Chord similarity method variables
        std::vector< std::vector<double> > _chordSimilarity;
        std::vector<double> _segmentChordCorrelation;
        unsigned _framesInSegment;
public:
        ChordSegmentator()
                : _segmentation(0)
                , _currentSegment(0)
                , _segmentOpen(false)
                , _lastChord(0)
                , _framesInSegment(0)
        {
                method(0);
        };
        ~ChordSegmentator() {};

        void doIt(CLAM::TData & currentTime, const std::vector<double> & correlation, const unsigned firstCandidate, const unsigned secondCandidate) 
        {
                _segmentation.maxPosition(currentTime);
                switch(_method)
                {
                        case 2:
                                doItSimilarity(currentTime, correlation, firstCandidate, secondCandidate); 
                                break;
                        default:
                                doItSimple(currentTime, correlation, firstCandidate, secondCandidate); 
                }
        }

        void doItSimple(CLAM::TData & currentTime, const std::vector<double> & correlation, const unsigned firstCandidate, const unsigned secondCandidate) 
        {
                CLAM::TData firstCandidateWeight = correlation[firstCandidate];
                CLAM::TData noCandidateWeight = correlation[0];
                
                unsigned currentChord = firstCandidateWeight*0.6<=noCandidateWeight || noCandidateWeight<0.001 ?
                                0 : firstCandidate;
                
                if(_segmentOpen)
                {
                        if(!currentChord)
                                closeSegment(currentTime);
                        if(currentChord != _lastChord)
                                closeSegment(currentTime);
                }
                if(!_segmentOpen)
                {       
                        if(currentChord)
                                openSegment(currentTime, currentChord);
                }
                
                _lastChord = currentChord;
                
                if(_segmentOpen)
                        _segmentation.dragOffset(_currentSegment, currentTime);
        }

        void doItSimilarity(CLAM::TData & currentTime, const std::vector<double> & correlation, const unsigned firstCandidate, const unsigned secondCandidate) 
        {
                CLAM::TData firstCandidateWeight = correlation[firstCandidate];
                CLAM::TData noCandidateWeight = correlation[0];
                
                unsigned currentChord = firstCandidateWeight*0.6<=noCandidateWeight || noCandidateWeight<0.001 ?
                                0 : firstCandidate;

                unsigned segmentChord=0;
                
                if(_segmentOpen)
                { 
                        for(unsigned i=0; i<correlation.size(); i++) 
                                _segmentChordCorrelation[i] += correlation[i]/correlation[0];
                        _framesInSegment++;
                        estimateChord(_segmentChordCorrelation, segmentChord);
                        _chordIndexes[_currentSegment] = segmentChord;

                        double segmentCorrelationDiffNew = (_segmentChordCorrelation[segmentChord] - _segmentChordCorrelation[currentChord]) / _framesInSegment;

                        double similarity = _chordSimilarity[currentChord][segmentChord];
                        
                        double similarityThreshold = 0.67;
                        double correlationThreshold = 0.3;
                        
                        if(!currentChord) 
                        {
                                closeSegment(currentTime);
                                _framesInSegment = 0;
                                for(unsigned i=0; i<correlation.size(); i++) 
                                        _segmentChordCorrelation[i] = 0;
                        }

                        if (similarity < similarityThreshold)
                        {
                                if(segmentCorrelationDiffNew > correlationThreshold)
                                {
                                        closeSegment(currentTime);
                                        _framesInSegment = 0;
                                        for(unsigned i=0; i<correlation.size(); i++) 
                                                _segmentChordCorrelation[i] = 0;
                                }
                        }
                        
                }
                if(!_segmentOpen && currentChord)
                {       
                        openSegment(currentTime, currentChord);
                        for(unsigned i=0; i<correlation.size(); i++) 
                                _segmentChordCorrelation[i] = correlation[i]/correlation[0];
                        _framesInSegment++;
                        segmentChord=currentChord;
                }
                
                if(_segmentOpen)
                        _segmentation.dragOffset(_currentSegment, currentTime);
        }

        void openSegment(CLAM::TData & currentTime, unsigned currentChord)
        {
                _chordIndexes.push_back(currentChord);
                _currentSegment = _segmentation.insert(currentTime);
                _segmentOpen = true;
        }
        void closeSegment(CLAM::TData & currentTime)
        {
                _segmentation.dragOffset(_currentSegment, currentTime);
                _segmentOpen = false;
                
                switch(_method)
                {
                        case 1:
                                changeChordIfSegmentTooSmall(_currentSegment);
                                break;
                        case 2:
                                changeChordIfSegmentTooSmall(_currentSegment);
                                break;
                }

                mergeSegmentIfIdenticalChordInPreviousSegment(_currentSegment);
        }       

        void changeChordIfSegmentTooSmall(unsigned & segment)
        {
                double minSegmentLength = 0.5;
                
                std::vector<double> onsets = _segmentation.onsets();
                std::vector<double> offsets = _segmentation.offsets();
                unsigned lastSegment = onsets.size();
                CLAM_ASSERT(segment<lastSegment, "changeChordIfSegmentTooSmall: Accessing a segment beyond lastSegment");

                if(offsets[segment]-onsets[segment] < minSegmentLength)
                {
                        if(segment<lastSegment)
                                if(offsets[segment]==onsets[segment+1])
                                        _chordIndexes[segment] = _chordIndexes[segment+1];
                        if(segment>0)
                                if(onsets[segment]==offsets[segment-1])
                                        _chordIndexes[segment] = _chordIndexes[segment-1];
                }
        }
        void mergeSegmentIfIdenticalChordInPreviousSegment(unsigned & segment)
        {
                CLAM::TData time = _segmentation.offsets()[segment];
                if(segment>0)
                {
                        if(_chordIndexes[segment] == _chordIndexes[segment-1]
                                && _segmentation.onsets()[segment] == _segmentation.offsets()[segment-1])
                        {
                                _segmentation.remove(segment);
                                _chordIndexes.erase(_chordIndexes.begin()+segment);
                                segment--;
                                _segmentation.dragOffset(segment, time);
                        }
                }
        }

        void closeLastSegment(CLAM::TData & currentTime )
        {
                _segmentation.maxPosition(currentTime);
                
                if (_lastChord != 0)
                {
                        _segmentation.dragOffset(_currentSegment, currentTime);
                        _segmentOpen = false;
                }
                
                switch(_method)
                {
                        case 1:
                                changeChordsForSmallSegments();
                                joinSegmentsWithIdenticalChords();
                                break;
                }
        }

        void eraseAllSegments()
        {
                while( _segmentation.onsets().size() )
                {
                        _segmentation.remove(_segmentation.onsets().size()-1);
                        _chordIndexes.pop_back();
                }
                _segmentation.maxPosition(0);
        }

        void estimateChord(const ChordCorrelator::ChordCorrelation & correlation, unsigned & estimatedChord)
        {
                double maxCorrelation = 0;
                double underMaxCorrelation = 0;
                unsigned maxIndex = 0;
                unsigned underMaxIndex = 0;
                for (unsigned i=0; i<correlation.size(); i++)
                {
                        if (correlation[i]<underMaxCorrelation) continue;
                        if (correlation[i]<maxCorrelation)
                        {
                                underMaxIndex=i;
                                underMaxCorrelation=correlation[i];
                                continue;
                        }
                        underMaxIndex=maxIndex;
                        underMaxCorrelation=maxCorrelation;
                        maxIndex=i;
                        maxCorrelation=correlation[i];
                }
                estimatedChord = maxIndex;
        }
        
        //
        // Post Processing Functions
        //
        
        void changeChordsForSmallSegments()
        {
                for(unsigned segment=0; segment<_segmentation.onsets().size(); segment++)
                        changeChordIfSegmentTooSmall(segment);
        }
        void joinSegmentsWithIdenticalChords()
        {
                for(unsigned segment=1; segment<_segmentation.onsets().size(); segment++)
                        mergeSegmentIfIdenticalChordInPreviousSegment(segment);
        }

        const CLAM::DiscontinuousSegmentation & segmentation() const { return _segmentation; };
        const std::vector<unsigned> & chordIndexes() const { return _chordIndexes; };
        void method(unsigned method) 
        { 
                _method=method; 
                if(method != 0 && method != 1 && method != 2)
                        _method = 0;

                switch(_method)
                {
                        case 2:
                                ChordCorrelator chordCorrelator;
                                _chordSimilarity = chordCorrelator.chordPatternsSimilarity();
                                for(unsigned i=0; i<101; ++i)
                                        _segmentChordCorrelation.push_back(0);
                                break;
                }
        }
};
}
#endif//ChordSegmentator