Chris@6: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@6: 
Chris@6: /*
Chris@6:   Vamp feature extraction plugin for the BeatRoot beat tracker.
Chris@6: 
Chris@6:   Centre for Digital Music, Queen Mary, University of London.
Chris@6:   This file copyright 2011 Simon Dixon, Chris Cannam and QMUL.
Chris@6:     
Chris@6:   This program is free software; you can redistribute it and/or
Chris@6:   modify it under the terms of the GNU General Public License as
Chris@6:   published by the Free Software Foundation; either version 2 of the
Chris@6:   License, or (at your option) any later version.  See the file
Chris@6:   COPYING included with this distribution for more information.
Chris@6: */
Chris@6: 
Chris@6: #ifndef _BEAT_TRACKER_H_
Chris@6: #define _BEAT_TRACKER_H_
Chris@6: 
Chris@6: #include "Event.h"
Chris@6: #include "Agent.h"
Chris@8: #include "AgentList.h"
Chris@7: #include "Induction.h"
Chris@6: 
Chris@6: using std::vector;
Chris@6: 
Chris@6: class BeatTracker
Chris@6: {
Chris@6: protected:
Chris@6:     /** beat data encoded as a list of Events */
Chris@6:     EventList beats;
Chris@6: 	
Chris@6:     /** a list of onset events for passing to the tempo induction and beat tracking methods */
Chris@6:     EventList onsetList;
Chris@6: 	
Chris@6:     /** the times of onsets (in seconds) */
Chris@6:     vector<double> onsets;
Chris@6: 
Chris@6: public:
Chris@6:     /** Constructor:
Chris@6:      *  @param b The list of beats
Chris@6:      */
Chris@6:     BeatTracker(EventList b) {
Chris@6: 	beats = b;
Chris@6:     } // BeatTracker constructor
Chris@6: 
Chris@6:     /** Creates a new Event object representing a beat.
Chris@6:      *  @param time The time of the beat in seconds
Chris@6:      *  @param beatNum The index of the beat
Chris@6:      *  @return The Event object representing the beat
Chris@6:      */
Chris@6:     static Event newBeat(double time, int beatNum) {
Chris@6: 	return Event(time, beatNum, 0);
Chris@6:     } // newBeat()
Chris@6: 
Chris@6:     /** Perform beat tracking.
Chris@6:      *  @param events The onsets or peaks in a feature list
Chris@6:      *  @return The list of beats, or an empty list if beat tracking fails
Chris@6:      */
Chris@6:     static EventList beatTrack(EventList events) {
Chris@6: 	return beatTrack(events, EventList());
Chris@6:     }
Chris@6: 	
Chris@6:     /** Perform beat tracking.
Chris@6:      *  @param events The onsets or peaks in a feature list
Chris@6:      *  @param beats The initial beats which are given, if any
Chris@6:      *  @return The list of beats, or an empty list if beat tracking fails
Chris@6:      */
Chris@6:     static EventList beatTrack(EventList events, EventList beats) {
Chris@7: 	AgentList agents;
Chris@6: 	int count = 0;
Chris@6: 	double beatTime = -1;
Chris@6: 	if (!beats.empty()) {
Chris@6: 	    count = beats.size() - 1;
Chris@7: 	    EventList::iterator itr = beats.end();
Chris@7: 	    --itr;
Chris@7: 	    beatTime = itr->time;
Chris@6: 	}
Chris@6: 	if (count > 0) { // tempo given by mean of initial beats
Chris@8: 	    double ioi = (beatTime - beats.begin()->time) / count;
Chris@8: 	    agents.push_back(Agent(ioi));
Chris@8: 	} else // tempo not given; use tempo induction
Chris@8: 	    agents = Induction::beatInduction(events);
Chris@8: 	if (!beats.empty())
Chris@8: 	    for (AgentList::iterator itr = agents.begin(); itr != agents.end();
Chris@8:                  ++itr) {
Chris@8: 		itr->beatTime = beatTime;
Chris@8: 		itr->beatCount = count;
Chris@8: 		itr->events = beats;
Chris@6: 	    }
Chris@6: 	agents.beatTrack(events, -1);
Chris@8: 	Agent *best = agents.bestAgent();
Chris@8: 	if (best) {
Chris@8: 	    best->fillBeats(beatTime);
Chris@8: 	    return best->events;
Chris@6: 	}
Chris@8: 	return EventList();
Chris@6:     } // beatTrack()/1
Chris@6: 	
Chris@6:     /** Finds the mean tempo (as inter-beat interval) from an array of beat times
Chris@6:      *  @param d An array of beat times
Chris@6:      *  @return The average inter-beat interval
Chris@6:      */
Chris@6:     static double getAverageIBI(vector<double> d) {
Chris@8: 	if (d.size() < 2)
Chris@6: 	    return -1.0;
Chris@8: 	return (d[d.size() - 1] - d[0]) / (d.size() - 1);
Chris@6:     } // getAverageIBI()
Chris@6: 	
Chris@6:     /** Finds the median tempo (as inter-beat interval) from an array of beat times
Chris@6:      *  @param d An array of beat times
Chris@6:      *  @return The median inter-beat interval
Chris@6:      */
Chris@6:     static double getMedianIBI(vector<double> d) {
Chris@8: 	if (d.size() < 2)
Chris@6: 	    return -1.0;
Chris@8: 	vector<double> ibi;
Chris@8:         ibi.resize(d.size()-1);
Chris@8: 	for (int i = 1; i < d.size(); i++)
Chris@6: 	    ibi[i-1] = d[i] - d[i-1];
Chris@8:         std::sort(ibi.begin(), ibi.end());
Chris@8: 	if (ibi.size() % 2 == 0)
Chris@8: 	    return (ibi[ibi.size() / 2] + ibi[ibi.size() / 2 - 1]) / 2;
Chris@6: 	else
Chris@8: 	    return ibi[ibi.size() / 2];
Chris@6:     } // getAverageIBI()
Chris@6: 	
Chris@6: 	
Chris@6:     // Various get and set methods
Chris@6: 	
Chris@6:     /** @return the list of beats */
Chris@6:     EventList getBeats() {
Chris@6: 	return beats;
Chris@6:     } // getBeats()
Chris@6: 
Chris@6:     /** @return the array of onset times */
Chris@6:     vector<double> getOnsets() {
Chris@6: 	return onsets;
Chris@6:     } // getOnsets()
Chris@6: 
Chris@6:     /** Sets the onset times as a list of Events, for use by the beat tracking methods. 
Chris@6:      *  @param on The times of onsets in seconds
Chris@6:      */
Chris@6:     void setOnsetList(EventList on) {
Chris@6: 	onsetList = on;
Chris@6:     } // setOnsetList()
Chris@6: 
Chris@6:     /** Sets the array of onset times, for displaying MIDI or audio input data.
Chris@6:      *  @param on The times of onsets in seconds
Chris@6:      */
Chris@6:     void setOnsets(vector<double> on) {
Chris@6: 	onsets = on;
Chris@6:     } // setOnsets()
Chris@6: 
Chris@6:     /** Sets the list of beats.
Chris@6:      * @param b The list of beats
Chris@6:      */
Chris@6:     void setBeats(EventList b) {
Chris@6: 	beats = b;
Chris@6:     } // setBeats()
Chris@6: 
Chris@6: }; // class BeatTrackDisplay
Chris@6: 
Chris@6: 
Chris@6: #endif
Chris@6: