Chris@49: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@0: 
Chris@0: /*
Chris@52:     Sonic Visualiser
Chris@52:     An audio file viewer and annotation editor.
Chris@52:     Centre for Digital Music, Queen Mary, University of London.
Chris@52:     This file copyright 2006 Chris Cannam.
Chris@0:     
Chris@52:     This program is free software; you can redistribute it and/or
Chris@52:     modify it under the terms of the GNU General Public License as
Chris@52:     published by the Free Software Foundation; either version 2 of the
Chris@52:     License, or (at your option) any later version.  See the file
Chris@52:     COPYING included with this distribution for more information.
Chris@0: */
Chris@0: 
Chris@1581: #ifndef SV_WINDOW_H
Chris@1581: #define SV_WINDOW_H
Chris@0: 
Chris@0: #include <cmath>
Chris@0: #include <iostream>
Chris@350: #include <string>
Chris@0: #include <map>
Chris@402: #include <cstdlib>
Chris@0: 
Chris@1270: #include <bqvec/VectorOps.h>
Chris@1270: #include <bqvec/Allocators.h>
Chris@1270: 
Chris@1059: #include "system/System.h"
Chris@405: 
Chris@0: enum WindowType {
Chris@0:     RectangularWindow,
Chris@0:     BartlettWindow,
Chris@0:     HammingWindow,
Chris@0:     HanningWindow,
Chris@0:     BlackmanWindow,
Chris@0:     GaussianWindow,
Chris@142:     ParzenWindow,
Chris@142:     NuttallWindow,
Chris@142:     BlackmanHarrisWindow
Chris@0: };
Chris@0: 
Chris@0: template <typename T>
Chris@0: class Window
Chris@0: {
Chris@0: public:
Chris@0:     /**
Chris@813:      * Construct a windower of the given type and size. 
Chris@813:      *
Chris@813:      * Note that the cosine windows are periodic by design, rather
Chris@813:      * than symmetrical. (A window of size N is equivalent to a
Chris@813:      * symmetrical window of size N+1 with the final element missing.)
Chris@0:      */
Chris@1270:     Window(WindowType type, int size) : m_type(type), m_size(size), m_cache(0) {
Chris@1270:         encache();
Chris@1270:     }
Chris@1270:     Window(const Window &w) : m_type(w.m_type), m_size(w.m_size), m_cache(0) {
Chris@1270:         encache();
Chris@1270:     }
Chris@0:     Window &operator=(const Window &w) {
Chris@1429:         if (&w == this) return *this;
Chris@1429:         m_type = w.m_type;
Chris@1429:         m_size = w.m_size;
Chris@1429:         encache();
Chris@1429:         return *this;
Chris@0:     }
Chris@1270:     virtual ~Window() {
Chris@1270:         breakfastquay::deallocate(m_cache);
Chris@1270:     }
Chris@0:     
Chris@1270:     inline void cut(T *const BQ_R__ block) const {
Chris@1270:         breakfastquay::v_multiply(block, m_cache, m_size);
Chris@1270:     }
Chris@1270: 
Chris@1270:     inline void cut(const T *const BQ_R__ src, T *const BQ_R__ dst) const {
Chris@1270:         breakfastquay::v_multiply(dst, src, m_cache, m_size);
Chris@0:     }
Chris@0: 
Chris@162:     T getArea() { return m_area; }
Chris@928:     T getValue(int i) { return m_cache[i]; }
Chris@140: 
Chris@0:     WindowType getType() const { return m_type; }
Chris@928:     int getSize() const { return m_size; }
Chris@0: 
Chris@350:     // The names used by these functions are un-translated, for use in
Chris@350:     // e.g. XML I/O.  Use Preferences::getPropertyValueLabel if you
Chris@350:     // want translated names for use in the user interface.
Chris@350:     static std::string getNameForType(WindowType type);
Chris@350:     static WindowType getTypeForName(std::string name);
Chris@350: 
Chris@0: protected:
Chris@0:     WindowType m_type;
Chris@928:     int m_size;
Chris@1270:     T *BQ_R__ m_cache;
Chris@162:     T m_area;
Chris@0:     
Chris@0:     void encache();
Chris@1038:     void cosinewin(T *, double, double, double, double);
Chris@0: };
Chris@0: 
Chris@0: template <typename T>
Chris@0: void Window<T>::encache()
Chris@0: {
Chris@1270:     if (!m_cache) m_cache = breakfastquay::allocate<T>(m_size);
Chris@1270: 
Chris@928:     const int n = m_size;
Chris@1270:     breakfastquay::v_set(m_cache, T(1.0), n);
Chris@141:     int i;
Chris@0: 
Chris@0:     switch (m_type) {
Chris@1429:                 
Chris@0:     case RectangularWindow:
Chris@1429:         for (i = 0; i < n; ++i) {
Chris@1429:             m_cache[i] *= T(0.5);
Chris@1429:         }
Chris@1429:         break;
Chris@1429:             
Chris@0:     case BartlettWindow:
Chris@1429:         for (i = 0; i < n/2; ++i) {
Chris@1429:             m_cache[i] *= T(i) / T(n/2);
Chris@1429:             m_cache[i + n/2] *= T(1.0) - T(i) / T(n/2);
Chris@1429:         }
Chris@1429:         break;
Chris@1429:             
Chris@0:     case HammingWindow:
Chris@1270:         cosinewin(m_cache, 0.54, 0.46, 0.0, 0.0);
Chris@1429:         break;
Chris@1429:             
Chris@0:     case HanningWindow:
Chris@1270:         cosinewin(m_cache, 0.50, 0.50, 0.0, 0.0);
Chris@1429:         break;
Chris@1429:             
Chris@0:     case BlackmanWindow:
Chris@1270:         cosinewin(m_cache, 0.42, 0.50, 0.08, 0.0);
Chris@1429:         break;
Chris@1429:             
Chris@0:     case GaussianWindow:
Chris@1429:         for (i = 0; i < n; ++i) {
Chris@1270:             m_cache[i] *= T(pow(2, - pow((i - (n-1)/2.0) / ((n-1)/2.0 / 3), 2)));
Chris@1429:         }
Chris@1429:         break;
Chris@1429:             
Chris@0:     case ParzenWindow:
Chris@141:     {
Chris@141:         int N = n-1;
Chris@141:         for (i = 0; i < N/4; ++i) {
Chris@1038:             T m = T(2 * pow(1.0 - (T(N)/2 - T(i)) / (T(N)/2), 3));
Chris@1270:             m_cache[i] *= m;
Chris@1270:             m_cache[N-i] *= m;
Chris@141:         }
Chris@141:         for (i = N/4; i <= N/2; ++i) {
Chris@141:             int wn = i - N/2;
Chris@1038:             T m = T(1.0 - 6 * pow(T(wn) / (T(N)/2), 2) * (1.0 - T(abs(wn)) / (T(N)/2)));
Chris@1270:             m_cache[i] *= m;
Chris@1270:             m_cache[N-i] *= m;
Chris@141:         }            
Chris@142:         break;
Chris@142:     }
Chris@142: 
Chris@142:     case NuttallWindow:
Chris@1270:         cosinewin(m_cache, 0.3635819, 0.4891775, 0.1365995, 0.0106411);
Chris@1429:         break;
Chris@142: 
Chris@142:     case BlackmanHarrisWindow:
Chris@1270:         cosinewin(m_cache, 0.35875, 0.48829, 0.14128, 0.01168);
Chris@142:         break;
Chris@0:     }
Chris@1429:         
Chris@162:     m_area = 0;
Chris@162:     for (int i = 0; i < n; ++i) {
Chris@162:         m_area += m_cache[i];
Chris@162:     }
Chris@1038:     m_area /= T(n);
Chris@0: }
Chris@0: 
Chris@142: template <typename T>
Chris@1038: void Window<T>::cosinewin(T *mult, double a0, double a1, double a2, double a3)
Chris@142: {
Chris@928:     const int n = m_size;
Chris@142:     for (int i = 0; i < n; ++i) {
Chris@1038:         mult[i] *= T(a0
Chris@1038:                      - a1 * cos((2 * M_PI * i) / n)
Chris@1038:                      + a2 * cos((4 * M_PI * i) / n)
Chris@1038:                      - a3 * cos((6 * M_PI * i) / n));
Chris@142:     }
Chris@142: }
Chris@142: 
Chris@350: template <typename T>
Chris@350: std::string
Chris@350: Window<T>::getNameForType(WindowType type)
Chris@350: {
Chris@350:     switch (type) {
Chris@350:     case RectangularWindow:    return "rectangular";
Chris@350:     case BartlettWindow:       return "bartlett";
Chris@350:     case HammingWindow:        return "hamming";
Chris@350:     case HanningWindow:        return "hanning";
Chris@350:     case BlackmanWindow:       return "blackman";
Chris@350:     case GaussianWindow:       return "gaussian";
Chris@350:     case ParzenWindow:         return "parzen";
Chris@350:     case NuttallWindow:        return "nuttall";
Chris@350:     case BlackmanHarrisWindow: return "blackman-harris";
Chris@350:     }
Chris@350: 
Chris@350:     std::cerr << "WARNING: Window::getNameForType: unknown type "
Chris@350:               << type << std::endl;
Chris@350: 
Chris@350:     return "unknown";
Chris@350: }
Chris@350: 
Chris@350: template <typename T>
Chris@350: WindowType
Chris@350: Window<T>::getTypeForName(std::string name)
Chris@350: {
Chris@350:     if (name == "rectangular")     return RectangularWindow;
Chris@350:     if (name == "bartlett")        return BartlettWindow;
Chris@350:     if (name == "hamming")         return HammingWindow;
Chris@350:     if (name == "hanning")         return HanningWindow;
Chris@350:     if (name == "blackman")        return BlackmanWindow;
Chris@350:     if (name == "gaussian")        return GaussianWindow;
Chris@350:     if (name == "parzen")          return ParzenWindow;
Chris@350:     if (name == "nuttall")         return NuttallWindow;
Chris@350:     if (name == "blackman-harris") return BlackmanHarrisWindow;
Chris@350: 
Chris@350:     std::cerr << "WARNING: Window::getTypeForName: unknown name \""
Chris@350:               << name << "\", defaulting to \"hanning\"" << std::endl;
Chris@350: 
Chris@350:     return HanningWindow;
Chris@350: }
Chris@350: 
Chris@0: #endif