comparison src/FeatureConditioner.cpp @ 103:593054bf6476 feature_conditioner

Pull out normalisation and specdiff stuff into FeatureConditioner

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Vamp feature extraction plugin using the MATCH audio alignment
+    algorithm.
+
+    Centre for Digital Music, Queen Mary, University of London.
+    
+    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.  See the file
+    COPYING included with this distribution for more information.
+*/
+
+#include "FeatureConditioner.h"
+
+#include <iostream>
+
+using namespace std;
+
+vector<double>
+FeatureConditioner::process(const vector<double> &feature)
+{
+    if (m_prev.empty()) {
+	m_prev.resize(feature.size(), 0.0);
+    }
+    if (m_prev.size() != feature.size()) {
+	cerr << "ERROR: FeatureConditioner::process: feature size "
+	     << feature.size() << " differs from previous feature size "
+	     << m_prev.size() << endl;
+	return feature;
+    }
+
+    int size = feature.size();
+    
+    vector<double> out(size, 0.0);
+
+    double totalEnergy = 0;
+    if (m_params.order == OutputRectifiedDerivative) {
+        for (int i = 0; i < size; i++) {
+            totalEnergy += feature[i];
+            if (feature[i] > m_prev[i]) {
+                out[i] = feature[i] - m_prev[i];
+            } else {
+                out[i] = 0;
+            }
+        }
+    } else {
+        for (int i = 0; i < size; i++) {
+            out[i] = feature[i];
+            totalEnergy += out[i];
+        }
+    }
+
+    if (m_ltAverage == 0) {
+	m_ltAverage = totalEnergy;
+    } else {
+	double decay = m_params.decay;
+        m_ltAverage = m_ltAverage * decay + totalEnergy * (1.0 - decay);
+    }
+
+    if (totalEnergy <= m_params.silenceThreshold) {
+        for (int i = 0; i < size; i++) {
+            out[i] = 0;
+	}
+    } else if (m_params.norm == NormaliseToSum1) {
+        for (int i = 0; i < size; i++) { 
+            out[i] /= totalEnergy;
+	}
+    } else if (m_params.norm == NormaliseToLTAverage) {
+        for (int i = 0; i < size; i++) {
+            out[i] /= m_ltAverage;
+	}
+    }
+
+    m_prev = feature;
+    return out;
+}
+