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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
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/*
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    This file is Copyright (c) 2012 Chris Cannam
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    Permission is hereby granted, free of charge, to any person
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    obtaining a copy of this software and associated documentation
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    files (the "Software"), to deal in the Software without
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    restriction, including without limitation the rights to use, copy,
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    modify, merge, publish, distribute, sublicense, and/or sell copies
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    of the Software, and to permit persons to whom the Software is
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    furnished to do so, subject to the following conditions:
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    The above copyright notice and this permission notice shall be
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    included in all copies or substantial portions of the Software.
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    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
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    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include "NoteHypothesis.h"
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#include <cmath>
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using Vamp::RealTime;
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NoteHypothesis::NoteHypothesis()
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{
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    m_state = New;
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}
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NoteHypothesis::~NoteHypothesis()
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{
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}
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bool
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NoteHypothesis::isWithinTolerance(Estimate s) const
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{
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    if (m_pending.empty()) {
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        return true;
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    }
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    // check we are within a relatively close tolerance of the last
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    // candidate
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    Estimate last = m_pending[m_pending.size()-1];
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    double r = s.freq / last.freq;
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    int cents = lrint(1200.0 * (log(r) / log(2.0)));
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    if (cents < -60 || cents > 60) return false;
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    // and within a slightly bigger tolerance of the current mean
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    double meanFreq = getMeanFrequency();
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    r = s.freq / meanFreq;
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    cents = lrint(1200.0 * (log(r) / log(2.0)));
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    if (cents < -80 || cents > 80) return false;
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    return true;
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}
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bool
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NoteHypothesis::isOutOfDateFor(Estimate s) const
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{
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    if (m_pending.empty()) return false;
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    return ((s.time - m_pending[m_pending.size()-1].time) >
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            RealTime::fromMilliseconds(40));
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}
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bool
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NoteHypothesis::isSatisfied() const
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{
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    if (m_pending.empty()) return false;
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    double meanConfidence = 0.0;
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    for (int i = 0; i < (int)m_pending.size(); ++i) {
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        meanConfidence += m_pending[i].confidence;
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    }
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    meanConfidence /= m_pending.size();
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    int lengthRequired = 10000;
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    if (meanConfidence > 0.0) {
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        lengthRequired = int(2.0 / meanConfidence + 0.5);
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    }
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    return ((int)m_pending.size() > lengthRequired);
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}
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bool
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NoteHypothesis::accept(Estimate s)
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{
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    bool accept = false;
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    static double negligibleConfidence = 0.0001;
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    if (s.confidence < negligibleConfidence) {
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        // avoid piling up a lengthy sequence of estimates that are
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        // all acceptable but are in total not enough to cause us to
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        // be satisfied
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        m_state = Rejected;
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        return false;
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    }
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    switch (m_state) {
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    case New:
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        m_state = Provisional;
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        accept = true;
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        break;
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    case Provisional:
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        if (isOutOfDateFor(s)) {
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            m_state = Rejected;
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        } else if (isWithinTolerance(s)) {
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            accept = true;
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        }
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        break;
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    case Satisfied:
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        if (isOutOfDateFor(s)) {
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            m_state = Expired;
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        } else if (isWithinTolerance(s)) {
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            accept = true;
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        }
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        break;
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    case Rejected:
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        break;
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    case Expired:
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        break;
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    }
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    if (accept) {
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        m_pending.push_back(s);
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        if (m_state == Provisional && isSatisfied()) {
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            m_state = Satisfied;
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        }
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    }
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    return accept;
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}
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NoteHypothesis::State
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NoteHypothesis::getState() const
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{
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    return m_state;
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}
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NoteHypothesis::Estimates
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NoteHypothesis::getAcceptedEstimates() const
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{
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    if (m_state == Satisfied || m_state == Expired) {
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        return m_pending;
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    } else {
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        return Estimates();
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    }
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}
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RealTime
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NoteHypothesis::getStartTime() const
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{
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    if (!(m_state == Satisfied || m_state == Expired)) {
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        return RealTime::zeroTime;
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    } else {
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        return m_pending.begin()->time;
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    }
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}
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double
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NoteHypothesis::getMeanFrequency() const
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{
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    double acc = 0.0;
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    if (m_pending.empty()) return acc;
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    for (int i = 0; i < (int)m_pending.size(); ++i) {
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        acc += m_pending[i].freq;
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    }
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    acc /= m_pending.size();
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    return acc;
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}
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NoteHypothesis::Note
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NoteHypothesis::getAveragedNote() const
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{
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    Note n;
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    if (!(m_state == Satisfied || m_state == Expired)) {
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        n.freq = 0.0;
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        n.time = RealTime::zeroTime;
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        n.duration = RealTime::zeroTime;
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        return n;
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    }
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    n.time = m_pending.begin()->time;
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    Estimates::const_iterator i = m_pending.end();
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    --i;
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    n.duration = i->time - n.time;
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    // just mean frequency for now, but this isn't at all right perceptually
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    n.freq = getMeanFrequency();
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    return n;
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}