comparison src/dsp/SincWindow.h @ 119:a38d6940f8fb

Bring in dsp dependencies

+/* -*- 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 SINC_WINDOW_H
+#define SINC_WINDOW_H
+
+#include <vector>
+
+/**
+ * A window containing values of the sinc function, i.e. sin(x)/x with
+ * sinc(0) == 1, with x == 0 at the centre.
+ */
+class SincWindow
+{
+public:
+    /**
+     * Construct a windower of the given length, containing the values
+     * of sinc(x) with x=0 in the middle, i.e. at sample (length-1)/2
+     * for odd or (length/2)+1 for even length, such that the distance
+     * from -pi to pi (the nearest zero crossings either side of the
+     * peak) is p samples.
+     */
+    SincWindow(int length, double p) : m_length(length), m_p(p) { init(); }
+
+    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_p;
+    std::vector<double> m_window;
+
+    void init();
+};
+
+#endif