annotate base/Window.h @ 168:04baa690f90d

* Start adding StorageAdviser class to determine whether caches should be on disc or in memory
author Chris Cannam
date Mon, 25 Sep 2006 13:44:05 +0000
parents 3fe6660f8fe2
children 524bcd89743b
rev   line source
Chris@49 1 /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */
Chris@0 2
Chris@0 3 /*
Chris@52 4 Sonic Visualiser
Chris@52 5 An audio file viewer and annotation editor.
Chris@52 6 Centre for Digital Music, Queen Mary, University of London.
Chris@52 7 This file copyright 2006 Chris Cannam.
Chris@0 8
Chris@52 9 This program is free software; you can redistribute it and/or
Chris@52 10 modify it under the terms of the GNU General Public License as
Chris@52 11 published by the Free Software Foundation; either version 2 of the
Chris@52 12 License, or (at your option) any later version. See the file
Chris@52 13 COPYING included with this distribution for more information.
Chris@0 14 */
Chris@0 15
Chris@0 16 #ifndef _WINDOW_H_
Chris@0 17 #define _WINDOW_H_
Chris@0 18
Chris@0 19 #include <cmath>
Chris@0 20 #include <iostream>
Chris@0 21 #include <map>
Chris@0 22
Chris@0 23 enum WindowType {
Chris@0 24 RectangularWindow,
Chris@0 25 BartlettWindow,
Chris@0 26 HammingWindow,
Chris@0 27 HanningWindow,
Chris@0 28 BlackmanWindow,
Chris@0 29 GaussianWindow,
Chris@142 30 ParzenWindow,
Chris@142 31 NuttallWindow,
Chris@142 32 BlackmanHarrisWindow
Chris@0 33 };
Chris@0 34
Chris@0 35 template <typename T>
Chris@0 36 class Window
Chris@0 37 {
Chris@0 38 public:
Chris@0 39 /**
Chris@0 40 * Construct a windower of the given type.
Chris@0 41 */
Chris@0 42 Window(WindowType type, size_t size) : m_type(type), m_size(size) { encache(); }
Chris@0 43 Window(const Window &w) : m_type(w.m_type), m_size(w.m_size) { encache(); }
Chris@0 44 Window &operator=(const Window &w) {
Chris@52 45 if (&w == this) return *this;
Chris@0 46 m_type = w.m_type;
Chris@0 47 m_size = w.m_size;
Chris@0 48 encache();
Chris@0 49 return *this;
Chris@0 50 }
Chris@142 51 virtual ~Window() { delete[] m_cache; }
Chris@0 52
Chris@0 53 void cut(T *src) const { cut(src, src); }
Chris@0 54 void cut(T *src, T *dst) const {
Chris@0 55 for (size_t i = 0; i < m_size; ++i) dst[i] = src[i] * m_cache[i];
Chris@0 56 }
Chris@0 57
Chris@162 58 T getArea() { return m_area; }
Chris@140 59 T getValue(size_t i) { return m_cache[i]; }
Chris@140 60
Chris@0 61 WindowType getType() const { return m_type; }
Chris@0 62 size_t getSize() const { return m_size; }
Chris@0 63
Chris@0 64 protected:
Chris@0 65 WindowType m_type;
Chris@0 66 size_t m_size;
Chris@0 67 T *m_cache;
Chris@162 68 T m_area;
Chris@0 69
Chris@0 70 void encache();
Chris@142 71 void cosinewin(T *, T, T, T, T);
Chris@0 72 };
Chris@0 73
Chris@0 74 template <typename T>
Chris@0 75 void Window<T>::encache()
Chris@0 76 {
Chris@141 77 int n = int(m_size);
Chris@0 78 T *mult = new T[n];
Chris@141 79 int i;
Chris@0 80 for (i = 0; i < n; ++i) mult[i] = 1.0;
Chris@0 81
Chris@0 82 switch (m_type) {
Chris@0 83
Chris@0 84 case RectangularWindow:
Chris@0 85 for (i = 0; i < n; ++i) {
Chris@141 86 mult[i] *= 0.5;
Chris@0 87 }
Chris@0 88 break;
Chris@0 89
Chris@0 90 case BartlettWindow:
Chris@0 91 for (i = 0; i < n/2; ++i) {
Chris@141 92 mult[i] *= (i / T(n/2));
Chris@141 93 mult[i + n/2] *= (1.0 - (i / T(n/2)));
Chris@0 94 }
Chris@0 95 break;
Chris@0 96
Chris@0 97 case HammingWindow:
Chris@142 98 cosinewin(mult, 0.54, 0.46, 0.0, 0.0);
Chris@0 99 break;
Chris@0 100
Chris@0 101 case HanningWindow:
Chris@142 102 cosinewin(mult, 0.50, 0.50, 0.0, 0.0);
Chris@0 103 break;
Chris@0 104
Chris@0 105 case BlackmanWindow:
Chris@142 106 cosinewin(mult, 0.42, 0.50, 0.08, 0.0);
Chris@0 107 break;
Chris@0 108
Chris@0 109 case GaussianWindow:
Chris@0 110 for (i = 0; i < n; ++i) {
Chris@142 111 mult[i] *= pow(2, - pow((i - (n-1)/2.0) / ((n-1)/2.0 / 3), 2));
Chris@0 112 }
Chris@0 113 break;
Chris@0 114
Chris@0 115 case ParzenWindow:
Chris@141 116 {
Chris@141 117 int N = n-1;
Chris@141 118 for (i = 0; i < N/4; ++i) {
Chris@141 119 T m = 2 * pow(1.0 - (T(N)/2 - i) / (T(N)/2), 3);
Chris@141 120 mult[i] *= m;
Chris@141 121 mult[N-i] *= m;
Chris@141 122 }
Chris@141 123 for (i = N/4; i <= N/2; ++i) {
Chris@141 124 int wn = i - N/2;
Chris@141 125 T m = 1.0 - 6 * pow(wn / (T(N)/2), 2) * (1.0 - abs(wn) / (T(N)/2));
Chris@141 126 mult[i] *= m;
Chris@141 127 mult[N-i] *= m;
Chris@141 128 }
Chris@142 129 break;
Chris@142 130 }
Chris@142 131
Chris@142 132 case NuttallWindow:
Chris@142 133 cosinewin(mult, 0.3635819, 0.4891775, 0.1365995, 0.0106411);
Chris@0 134 break;
Chris@142 135
Chris@142 136 case BlackmanHarrisWindow:
Chris@142 137 cosinewin(mult, 0.35875, 0.48829, 0.14128, 0.01168);
Chris@142 138 break;
Chris@0 139 }
Chris@0 140
Chris@0 141 m_cache = mult;
Chris@162 142
Chris@162 143 m_area = 0;
Chris@162 144 for (int i = 0; i < n; ++i) {
Chris@162 145 m_area += m_cache[i];
Chris@162 146 }
Chris@162 147 m_area /= n;
Chris@0 148 }
Chris@0 149
Chris@142 150 template <typename T>
Chris@142 151 void Window<T>::cosinewin(T *mult, T a0, T a1, T a2, T a3)
Chris@142 152 {
Chris@142 153 int n = int(m_size);
Chris@142 154 for (int i = 0; i < n; ++i) {
Chris@142 155 mult[i] *= (a0
Chris@142 156 - a1 * cos(2 * M_PI * i / n)
Chris@142 157 + a2 * cos(4 * M_PI * i / n)
Chris@142 158 - a3 * cos(6 * M_PI * i / n));
Chris@142 159 }
Chris@142 160 }
Chris@142 161
Chris@0 162 #endif