Mercurial > hg > constant-q-cpp
diff src/dsp/SincWindow.cpp @ 119:a38d6940f8fb
Bring in dsp dependencies
author | Chris Cannam <c.cannam@qmul.ac.uk> |
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date | Thu, 15 May 2014 12:24:11 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/dsp/SincWindow.cpp Thu May 15 12:24:11 2014 +0100 @@ -0,0 +1,63 @@ +/* -*- 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. +*/ + +#include "SincWindow.h" + +#include <cmath> + +void +SincWindow::init() +{ + if (m_length < 1) { + return; + } else if (m_length < 2) { + m_window.push_back(1); + return; + } else { + + int n0 = (m_length % 2 == 0 ? m_length/2 : (m_length - 1)/2); + int n1 = (m_length % 2 == 0 ? m_length/2 : (m_length + 1)/2); + double m = 2 * M_PI / m_p; + + for (int i = 0; i < n0; ++i) { + double x = ((m_length / 2) - i) * m; + m_window.push_back(sin(x) / x); + } + + m_window.push_back(1.0); + + for (int i = 1; i < n1; ++i) { + double x = i * m; + m_window.push_back(sin(x) / x); + } + } +} +