Mercurial > hg > svcore
view base/Window.h @ 61:749b5521e082
* adjust for latency if the plugin reports it
author | Chris Cannam |
---|---|
date | Mon, 27 Mar 2006 16:15:19 +0000 |
parents | d397ea0a79f5 |
children | 534373d65f39 |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #ifndef _WINDOW_H_ #define _WINDOW_H_ #include <cmath> #include <iostream> #include <map> enum WindowType { RectangularWindow, BartlettWindow, HammingWindow, HanningWindow, BlackmanWindow, GaussianWindow, ParzenWindow }; template <typename T> class Window { public: /** * Construct a windower of the given type. */ Window(WindowType type, size_t size) : m_type(type), m_size(size) { encache(); } Window(const Window &w) : m_type(w.m_type), m_size(w.m_size) { encache(); } Window &operator=(const Window &w) { if (&w == this) return *this; m_type = w.m_type; m_size = w.m_size; encache(); return *this; } virtual ~Window() { delete m_cache; } void cut(T *src) const { cut(src, src); } void cut(T *src, T *dst) const { for (size_t i = 0; i < m_size; ++i) dst[i] = src[i] * m_cache[i]; } WindowType getType() const { return m_type; } size_t getSize() const { return m_size; } protected: WindowType m_type; size_t m_size; T *m_cache; void encache(); }; template <typename T> void Window<T>::encache() { size_t n = m_size; T *mult = new T[n]; size_t i; for (i = 0; i < n; ++i) mult[i] = 1.0; switch (m_type) { case RectangularWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * 0.5; } break; case BartlettWindow: for (i = 0; i < n/2; ++i) { mult[i] = mult[i] * (i / T(n/2)); mult[i + n/2] = mult[i + n/2] * (1.0 - (i / T(n/2))); } break; case HammingWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * (0.54 - 0.46 * cos(2 * M_PI * i / n)); } break; case HanningWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * (0.50 - 0.50 * cos(2 * M_PI * i / n)); } break; case BlackmanWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * (0.42 - 0.50 * cos(2 * M_PI * i / n) + 0.08 * cos(4 * M_PI * i / n)); } break; case GaussianWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * exp((-1.0 / (n*n)) * ((T(2*i) - n) * (T(2*i) - n))); } break; case ParzenWindow: for (i = 0; i < n; ++i) { mult[i] = mult[i] * (1.0 - fabs((T(2*i) - n) / T(n + 1))); } break; } m_cache = mult; } #endif