comparison constant-q-cpp/src/dsp/KaiserWindow.h @ 366:5d0a2ebb4d17

Bring dependent libraries in to repo

+/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
+/*
+    Constant-Q library
+    Copyright (c) 2013-2014 Queen Mary, University of London
+
+    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 AUTHOR 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.
+*/
+
+#ifndef KAISER_WINDOW_H
+#define KAISER_WINDOW_H
+
+#include <vector>
+#include <cmath>
+
+#include "pi.h"
+
+/**
+ * Kaiser window: A windower whose bandwidth and sidelobe height
+ * (signal-noise ratio) can be specified. These parameters are traded
+ * off against the window length.
+ */
+class KaiserWindow
+{
+public:
+    struct Parameters {
+	int length;
+	double beta;
+    };
+
+    /**
+     * Construct a Kaiser windower with the given length and beta
+     * parameter.
+     */
+    KaiserWindow(Parameters p) : m_length(p.length), m_beta(p.beta) { init(); }
+
+    /**
+     * Construct a Kaiser windower with the given attenuation in dB
+     * and transition width in samples.
+     */
+    static KaiserWindow byTransitionWidth(double attenuation,
+					  double transition) {
+	return KaiserWindow
+	    (parametersForTransitionWidth(attenuation, transition));
+    }
+
+    /**
+     * Construct a Kaiser windower with the given attenuation in dB
+     * and transition bandwidth in Hz for the given samplerate.
+     */
+    static KaiserWindow byBandwidth(double attenuation,
+				    double bandwidth,
+				    double samplerate) {
+	return KaiserWindow
+	    (parametersForBandwidth(attenuation, bandwidth, samplerate));
+    }
+
+    /**
+     * Obtain the parameters necessary for a Kaiser window of the
+     * given attenuation in dB and transition width in samples.
+     */
+    static Parameters parametersForTransitionWidth(double attenuation,
+						   double transition);
+
+    /**
+     * Obtain the parameters necessary for a Kaiser window of the
+     * given attenuation in dB and transition bandwidth in Hz for the
+     * given samplerate.
+     */
+    static Parameters parametersForBandwidth(double attenuation,
+					     double bandwidth,
+					     double samplerate) {
+	return parametersForTransitionWidth
+	    (attenuation, (bandwidth * 2 * M_PI) / samplerate);
+    } 
+
+    int getLength() const {
+	return m_length;
+    }
+
+    const double *getWindow() const { 
+	return m_window.data();
+    }
+
+    void cut(double *src) const { 
+	cut(src, src); 
+    }
+
+    void cut(const double *src, double *dst) const {
+	for (int i = 0; i < m_length; ++i) {
+	    dst[i] = src[i] * m_window[i];
+	}
+    }
+
+private:
+    int m_length;
+    double m_beta;
+    std::vector<double> m_window;
+
+    void init();
+};
+
+#endif