comparison examples/PowerSpectrum.cpp @ 241:70e6826adc64

* Add Power Spectrum example plugin

+/* -*- 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 2008 QMUL.
+  
+    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 AUTHORS 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 "PowerSpectrum.h"
+
+using std::string;
+using std::cerr;
+using std::endl;
+
+#include <math.h>
+
+PowerSpectrum::PowerSpectrum(float inputSampleRate) :
+    Plugin(inputSampleRate),
+    m_blockSize(0)
+{
+}
+
+PowerSpectrum::~PowerSpectrum()
+{
+}
+
+string
+PowerSpectrum::getIdentifier() const
+{
+    return "powerspectrum";
+}
+
+string
+PowerSpectrum::getName() const
+{
+    return "Simple Power Spectrum";
+}
+
+string
+PowerSpectrum::getDescription() const
+{
+    return "Return the power spectrum of a signal";
+}
+
+string
+PowerSpectrum::getMaker() const
+{
+    return "Vamp SDK Example Plugins";
+}
+
+int
+PowerSpectrum::getPluginVersion() const
+{
+    return 1;
+}
+
+string
+PowerSpectrum::getCopyright() const
+{
+    return "Freely redistributable (BSD license)";
+}
+
+bool
+PowerSpectrum::initialise(size_t channels, size_t stepSize, size_t blockSize)
+{
+    if (channels < getMinChannelCount() ||
+	channels > getMaxChannelCount()) return false;
+
+    m_blockSize = blockSize;
+
+    return true;
+}
+
+void
+PowerSpectrum::reset()
+{
+}
+
+PowerSpectrum::OutputList
+PowerSpectrum::getOutputDescriptors() const
+{
+    OutputList list;
+
+    OutputDescriptor d;
+    d.identifier = "powerspectrum";
+    d.name = "Power Spectrum";
+    d.description = "Power values of the frequency spectrum bins calculated from the input signal";
+    d.unit = "";
+    d.hasFixedBinCount = true;
+    d.binCount = m_blockSize / 2 + 1;
+    d.hasKnownExtents = false;
+    d.isQuantized = false;
+    d.sampleType = OutputDescriptor::OneSamplePerStep;
+    list.push_back(d);
+
+    return list;
+}
+
+PowerSpectrum::FeatureSet
+PowerSpectrum::process(const float *const *inputBuffers, Vamp::RealTime timestamp)
+{
+    FeatureSet fs;
+
+    if (m_blockSize == 0) {
+	cerr << "ERROR: PowerSpectrum::process: Not initialised" << endl;
+	return fs;
+    }
+
+    size_t n = m_blockSize / 2 + 1;
+    const float *fbuf = inputBuffers[0];
+
+    Feature feature;
+    feature.hasTimestamp = false;
+    feature.values.reserve(n); // optional
+
+    for (size_t i = 0; i < n; ++i) {
+
+	double real = fbuf[i * 2];
+	double imag = fbuf[i * 2 + 1];
+
+        feature.values.push_back(real * real + imag * imag);
+    }
+
+    fs[0].push_back(feature);
+
+    return fs;
+}
+
+PowerSpectrum::FeatureSet
+PowerSpectrum::getRemainingFeatures()
+{
+    return FeatureSet();
+}
+