diff examples/SpectralCentroid.cpp @ 0:6479539d1b32

* Importing first cut of Sonic Visualiser's Vamp plugin format SDK

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/SpectralCentroid.cpp	Fri Mar 31 14:21:51 2006 +0000
@@ -0,0 +1,211 @@
+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+
+/*
+    Vamp
+
+    An API for audio analysis and feature extraction plugins.
+
+    Centre for Digital Music, Queen Mary, University of London.
+    Copyright 2006 Chris Cannam.
+  
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR
+    ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+    CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+    WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+    Except as contained in this notice, the names of the Centre for
+    Digital Music; Queen Mary, University of London; and Chris Cannam
+    shall not be used in advertising or otherwise to promote the sale,
+    use or other dealings in this Software without prior written
+    authorization.
+*/
+
+#include "SpectralCentroid.h"
+
+/*
+#include "dsp/transforms/FFT.h"
+#include "base/Window.h"
+*/
+
+using std::string;
+using std::vector;
+using std::cerr;
+using std::endl;
+
+
+SpectralCentroid::SpectralCentroid(float inputSampleRate) :
+    Plugin(inputSampleRate),
+    m_stepSize(0),
+    m_blockSize(0),
+    m_workBuffer(0)
+{
+}
+
+SpectralCentroid::~SpectralCentroid()
+{
+    delete m_workBuffer;
+}
+
+string
+SpectralCentroid::getName() const
+{
+    return "spectralcentroid";
+}
+
+string
+SpectralCentroid::getDescription() const
+{
+    return "Spectral Centroid";
+}
+
+string
+SpectralCentroid::getMaker() const
+{
+    return "QMUL";
+}
+
+int
+SpectralCentroid::getPluginVersion() const
+{
+    return 2;
+}
+
+string
+SpectralCentroid::getCopyright() const
+{
+    return "GPL";
+}
+
+bool
+SpectralCentroid::initialise(size_t channels, size_t stepSize, size_t blockSize)
+{
+    if (channels < getMinChannelCount() ||
+	channels > getMaxChannelCount()) return false;
+
+    m_stepSize = stepSize;
+    m_blockSize = blockSize;
+
+    delete m_workBuffer;
+    m_workBuffer = new double[m_blockSize * 4];
+
+    return true;
+}
+
+void
+SpectralCentroid::reset()
+{
+    delete m_workBuffer;
+    m_workBuffer = new double[m_blockSize * 4];
+}
+
+size_t
+SpectralCentroid::getPreferredStepSize() const
+{
+    return 2048; // or whatever -- parameter?
+}
+
+size_t
+SpectralCentroid::getPreferredBlockSize() const
+{
+    return getPreferredStepSize();
+}
+
+SpectralCentroid::OutputList
+SpectralCentroid::getOutputDescriptors() const
+{
+    OutputList list;
+
+    OutputDescriptor d;
+    d.name = "logcentroid";
+    d.unit = "Hz";
+    d.description = "Log Frequency Centroid";
+    d.hasFixedValueCount = true;
+    d.valueCount = 1;
+    d.hasKnownExtents = false;
+    d.isQuantized = false;
+    d.sampleType = OutputDescriptor::OneSamplePerStep;
+    list.push_back(d);
+
+    d.name = "linearcentroid";
+    d.description = "Linear Frequency Centroid";
+    list.push_back(d);
+
+    return list;
+}
+
+SpectralCentroid::FeatureSet
+SpectralCentroid::process(float **inputBuffers, Vamp::RealTime)
+{
+    if (m_stepSize == 0) {
+	cerr << "ERROR: SpectralCentroid::process: "
+	     << "SpectralCentroid has not been initialised"
+	     << endl;
+	return FeatureSet();
+    }
+
+/*
+    for (size_t i = 0; i < m_blockSize; ++i) {
+	m_workBuffer[i] = inputBuffers[0][i];
+	m_workBuffer[i + m_blockSize] = 0.0;
+    }
+
+    Window<double>(HanningWindow, m_blockSize).cut(m_workBuffer);
+
+    FFT::process(m_blockSize, false,
+		 m_workBuffer,
+		 m_workBuffer + m_blockSize,
+		 m_workBuffer + m_blockSize*2,
+		 m_workBuffer + m_blockSize*3);
+*/
+
+    double numLin = 0.0, numLog = 0.0, denom = 0.0;
+
+    for (size_t i = 1; i < m_blockSize/2; ++i) {
+	double freq = (double(i) * m_inputSampleRate) / m_blockSize;
+	double real = inputBuffers[0][i*2];
+	double imag = inputBuffers[0][i*2 + 1];
+	double power = sqrt(real * real + imag * imag) / (m_blockSize/2);
+	numLin += freq * power;
+        numLog += log10f(freq) * power;
+	denom += power;
+    }
+
+    FeatureSet returnFeatures;
+
+    std::cerr << "power " << denom << ", block size " << m_blockSize << std::endl;
+
+    if (denom != 0.0) {
+	float centroidLin = float(numLin / denom);
+	float centroidLog = exp10f(float(numLog / denom));
+	Feature feature;
+	feature.hasTimestamp = false;
+	feature.values.push_back(centroidLog);
+	returnFeatures[0].push_back(feature);
+        feature.values.clear();
+	feature.values.push_back(centroidLin);
+	returnFeatures[1].push_back(feature);
+    }
+
+    return returnFeatures;
+}
+
+SpectralCentroid::FeatureSet
+SpectralCentroid::getRemainingFeatures()
+{
+    return FeatureSet();
+}
+