Chris@9: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@9: 
Chris@9: /*
Chris@9:     pYIN - A fundamental frequency estimator for monophonic audio
Chris@9:     Centre for Digital Music, Queen Mary, University of London.
Chris@9:     
Chris@9:     This program is free software; you can redistribute it and/or
Chris@9:     modify it under the terms of the GNU General Public License as
Chris@9:     published by the Free Software Foundation; either version 2 of the
Chris@9:     License, or (at your option) any later version.  See the file
Chris@9:     COPYING included with this distribution for more information.
Chris@9: */
Chris@9: 
matthiasm@0: #include "MonoNote.h"
matthiasm@0: #include <vector>
matthiasm@0: 
matthiasm@0: #include <cstdio>
matthiasm@0: #include <cmath>
matthiasm@0: #include <complex>
matthiasm@0: 
matthiasm@0: using std::vector;
matthiasm@0: using std::pair;
matthiasm@0: 
Chris@150: MonoNote::MonoNote(bool fixedLag) :
Chris@150:     m_fixedLag(fixedLag),
Chris@150:     hmm(m_fixedLag ? 1000 : 0)
matthiasm@0: {
matthiasm@0: }
matthiasm@0: 
matthiasm@0: MonoNote::~MonoNote()
matthiasm@0: {
matthiasm@0: }
matthiasm@0: 
matthiasm@0: const vector<MonoNote::FrameOutput>
matthiasm@0: MonoNote::process(const vector<vector<pair<double, double> > > pitchProb)
matthiasm@0: {
Chris@146:     // Previously, this built up a single matrix of probabilities, by
Chris@146:     // calling calculateObsProb to get a column for each frame in
Chris@146:     // pitchProb.
Chris@146:     //
Chris@146:     // The number of distinct states depends on MonoNoteParameters,
Chris@146:     // but the defaults have 3 states per pitch, 3 pitches per MIDI
Chris@146:     // note, and 69 MIDI notes, giving 681 states per frame. With a
Chris@146:     // frame step size of 256 at 44100Hz sample rate, a 3-minute song
Chris@146:     // has about 30K frames leading to a 20 million element
Chris@146:     // probability matrix.
Chris@146:     //
Chris@146:     // Since the matrix is very sparse, we can avoid some of this by
Chris@146:     // feeding the (sparse implementation of) HMM one column at a
Chris@146:     // time.
Chris@146: 
Chris@146:     vector<int> path;
Chris@150:     path.reserve(pitchProb.size());
Chris@146:     
Chris@146:     if (!pitchProb.empty()) {
Chris@146: 
Chris@146:         hmm.initialise(hmm.calculateObsProb(pitchProb[0]));
Chris@146:         
Chris@146:         for (size_t iFrame = 1; iFrame < pitchProb.size(); ++iFrame)
Chris@146:         {
Chris@150:             if (m_fixedLag && (int(iFrame) >= hmm.m_fixedLag)) 
Chris@150:             {
Chris@150:                 vector<int> rawPath = hmm.track();
Chris@150:                 path.push_back(rawPath[0]);
Chris@150:             }
Chris@150: 
Chris@146:             hmm.process(hmm.calculateObsProb(pitchProb[iFrame]));
Chris@146:         }
Chris@146: 
Chris@150:         vector<int> rawPath = hmm.track();
Chris@150:         path.insert(path.end(), rawPath.begin(), rawPath.end());
matthiasm@0:     }
matthiasm@0:     
Chris@150:     vector<MonoNote::FrameOutput> out;
Chris@150:     out.reserve(path.size());
Chris@146: 
matthiasm@0:     for (size_t iFrame = 0; iFrame < path.size(); ++iFrame)
matthiasm@0:     {
matthiasm@0:         double currPitch = -1;
matthiasm@0:         int stateKind = 0;
matthiasm@0: 
matthiasm@0:         currPitch = hmm.par.minPitch + (path[iFrame]/hmm.par.nSPP) * 1.0/hmm.par.nPPS;
matthiasm@0:         stateKind = (path[iFrame]) % hmm.par.nSPP + 1;
matthiasm@0: 
matthiasm@0:         out.push_back(FrameOutput(iFrame, currPitch, stateKind));
matthiasm@0:     }
Chris@146:     
matthiasm@0:     return(out);
Chris@9: }