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: #include "Agent.h"
Chris@6: #include "BeatTracker.h"
Chris@6: 
Chris@23: const double AgentParameters::DEFAULT_POST_MARGIN_FACTOR = 0.3;
Chris@23: const double AgentParameters::DEFAULT_PRE_MARGIN_FACTOR = 0.15;
Chris@23: const double AgentParameters::DEFAULT_MAX_CHANGE = 0.2;
Chris@23: const double AgentParameters::DEFAULT_EXPIRY_TIME = 10.0;
Chris@23: 
Chris@6: const double Agent::INNER_MARGIN = 0.040;
Chris@23: const double Agent::CONF_FACTOR = 0.5;
Chris@6: const double Agent::DEFAULT_CORRECTION_FACTOR = 50.0;
Chris@6: 
Chris@6: int Agent::idCounter = 0;
Chris@6: 
Chris@15: void Agent::accept(Event e, double err, int beats) {
Chris@15:     beatTime = e.time;
Chris@15:     events.push_back(e);
Chris@15:     if (fabs(initialBeatInterval - beatInterval -
Chris@23:              err / correctionFactor) < maxChange * initialBeatInterval)
Chris@15:         beatInterval += err / correctionFactor;// Adjust tempo
Chris@15:     beatCount += beats;
Chris@15:     double conFactor = 1.0 - CONF_FACTOR * err /
Chris@15:         (err>0? postMargin: -preMargin);
Chris@15:     if (decayFactor > 0) {
Chris@15:         double memFactor = 1. - 1. / threshold((double)beatCount,1,decayFactor);
Chris@15:         phaseScore = memFactor * phaseScore +
Chris@15:             (1.0 - memFactor) * conFactor * e.salience;
Chris@15:     } else
Chris@15:         phaseScore += conFactor * e.salience;
Chris@15: 
Chris@15: #ifdef DEBUG_BEATROOT
Chris@15:     std::cerr << "Ag#" << idNumber << ": " << beatInterval << std::endl;
Chris@15:     std::cerr << "  Beat" << beatCount << "  Time=" << beatTime
Chris@15:               << "  Score=" << tempoScore << ":P" << phaseScore << ":"
Chris@15:               << topScoreTime << std::endl;
Chris@15: #endif
Chris@15: } // accept()
Chris@15: 
Chris@8: bool Agent::considerAsBeat(Event e, AgentList &a) {
Chris@6:     double err;
Chris@6:     if (beatTime < 0) {	// first event
Chris@12: #ifdef DEBUG_BEATROOT
Chris@12:         std::cerr << "Ag#" << idNumber << ": accepting first event trivially at " << e.time << std::endl;
Chris@12: #endif
Chris@6: 	accept(e, 0, 1);
Chris@6: 	return true;
Chris@6:     } else {			// subsequent events
Chris@9:         EventList::iterator last = events.end();
Chris@9:         --last;
Chris@9: 	if (e.time - last->time > expiryTime) {
Chris@12: #ifdef DEBUG_BEATROOT
Chris@12:             std::cerr << "Ag#" << idNumber << ": time " << e.time 
Chris@12:                       << " too late relative to " << last->time << " (expiry "
Chris@12:                       << expiryTime << "), giving up" << std::endl;
Chris@12: #endif
Chris@6: 	    phaseScore = -1.0;	// flag agent to be deleted
Chris@6: 	    return false;
Chris@6: 	}
Chris@8: 	double beats = nearbyint((e.time - beatTime) / beatInterval);
Chris@8: 	err = e.time - beatTime - beats * beatInterval;
Chris@12: #ifdef DEBUG_BEATROOT
Chris@12:         std::cerr << "Ag#" << idNumber << ": time " << e.time << ", err " << err << " for beats " << beats << std::endl;
Chris@12: #endif
Chris@6: 	if ((beats > 0) && (-preMargin <= err) && (err <= postMargin)) {
Chris@16: 	    if (fabs(err) > innerMargin) {
Chris@12: #ifdef DEBUG_BEATROOT
Chris@12:                 std::cerr << "Ag#" << idNumber << ": creating another new agent" << std::endl;
Chris@12: #endif
Chris@16:                 // Create new agent that skips this event (avoids
Chris@16:                 // large phase jump)
Chris@16: 		a.add(clone());
Chris@12:             }
Chris@6: 	    accept(e, err, (int)beats);
Chris@6: 	    return true;
Chris@6: 	}
Chris@6:     }
Chris@6:     return false;
Chris@6: } // considerAsBeat()
Chris@6: 
Chris@6: 
Chris@9: void Agent::fillBeats(double start) {
Chris@6:     double prevBeat = 0, nextBeat, currentInterval, beats;
Chris@9:     EventList::iterator ei = events.begin();
Chris@9:     if (ei != events.end()) {
Chris@13:         EventList::iterator ni = ei;
Chris@18:         if (++ni != events.end()) {
Chris@18:             prevBeat = ni->time;
Chris@18:         }
Chris@6:     }
Chris@16:     while (ei != events.end()) {
Chris@13:         EventList::iterator ni = ei;
Chris@18:         if (ni == events.end() ||
Chris@18:             ++ni == events.end()) {
Chris@18:             break;
Chris@18:         }
Chris@16: 	nextBeat = ni->time;
Chris@6: 	beats = nearbyint((nextBeat - prevBeat) / beatInterval - 0.01); //prefer slow
Chris@6: 	currentInterval = (nextBeat - prevBeat) / beats;
Chris@6: 	for ( ; (nextBeat > start) && (beats > 1.5); beats--) {
Chris@6: 	    prevBeat += currentInterval;
Chris@13:             events.insert(ni, BeatTracker::newBeat(prevBeat, 0));
Chris@6: 	}
Chris@6: 	prevBeat = nextBeat;
Chris@13:         ei = ni;
Chris@6:     }
Chris@6: } // fillBeats()