Mercurial > hg > svcore
view base/Window.h @ 1583:c8fad3c14a2b bqaudiostream
Start wiring in BQAudioStream stuff
author | Chris Cannam |
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date | Thu, 06 Dec 2018 12:50:28 +0000 |
parents | 48e9f538e6e9 |
children | ad5f892c0c4d |
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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 <string> #include <map> #include <cstdlib> #include <bqvec/VectorOps.h> #include <bqvec/Allocators.h> #include "system/System.h" enum WindowType { RectangularWindow, BartlettWindow, HammingWindow, HanningWindow, BlackmanWindow, GaussianWindow, ParzenWindow, NuttallWindow, BlackmanHarrisWindow }; template <typename T> class Window { public: /** * Construct a windower of the given type and size. * * Note that the cosine windows are periodic by design, rather * than symmetrical. (A window of size N is equivalent to a * symmetrical window of size N+1 with the final element missing.) */ Window(WindowType type, int size) : m_type(type), m_size(size), m_cache(0) { encache(); } Window(const Window &w) : m_type(w.m_type), m_size(w.m_size), m_cache(0) { 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() { breakfastquay::deallocate(m_cache); } inline void cut(T *const BQ_R__ block) const { breakfastquay::v_multiply(block, m_cache, m_size); } inline void cut(const T *const BQ_R__ src, T *const BQ_R__ dst) const { breakfastquay::v_multiply(dst, src, m_cache, m_size); } T getArea() { return m_area; } T getValue(int i) { return m_cache[i]; } WindowType getType() const { return m_type; } int getSize() const { return m_size; } // The names used by these functions are un-translated, for use in // e.g. XML I/O. Use Preferences::getPropertyValueLabel if you // want translated names for use in the user interface. static std::string getNameForType(WindowType type); static WindowType getTypeForName(std::string name); protected: WindowType m_type; int m_size; T *BQ_R__ m_cache; T m_area; void encache(); void cosinewin(T *, double, double, double, double); }; template <typename T> void Window<T>::encache() { if (!m_cache) m_cache = breakfastquay::allocate<T>(m_size); const int n = m_size; breakfastquay::v_set(m_cache, T(1.0), n); int i; switch (m_type) { case RectangularWindow: for (i = 0; i < n; ++i) { m_cache[i] *= T(0.5); } break; case BartlettWindow: for (i = 0; i < n/2; ++i) { m_cache[i] *= T(i) / T(n/2); m_cache[i + n/2] *= T(1.0) - T(i) / T(n/2); } break; case HammingWindow: cosinewin(m_cache, 0.54, 0.46, 0.0, 0.0); break; case HanningWindow: cosinewin(m_cache, 0.50, 0.50, 0.0, 0.0); break; case BlackmanWindow: cosinewin(m_cache, 0.42, 0.50, 0.08, 0.0); break; case GaussianWindow: for (i = 0; i < n; ++i) { m_cache[i] *= T(pow(2, - pow((i - (n-1)/2.0) / ((n-1)/2.0 / 3), 2))); } break; case ParzenWindow: { int N = n-1; for (i = 0; i < N/4; ++i) { T m = T(2 * pow(1.0 - (T(N)/2 - T(i)) / (T(N)/2), 3)); m_cache[i] *= m; m_cache[N-i] *= m; } for (i = N/4; i <= N/2; ++i) { int wn = i - N/2; T m = T(1.0 - 6 * pow(T(wn) / (T(N)/2), 2) * (1.0 - T(abs(wn)) / (T(N)/2))); m_cache[i] *= m; m_cache[N-i] *= m; } break; } case NuttallWindow: cosinewin(m_cache, 0.3635819, 0.4891775, 0.1365995, 0.0106411); break; case BlackmanHarrisWindow: cosinewin(m_cache, 0.35875, 0.48829, 0.14128, 0.01168); break; } m_area = 0; for (int i = 0; i < n; ++i) { m_area += m_cache[i]; } m_area /= T(n); } template <typename T> void Window<T>::cosinewin(T *mult, double a0, double a1, double a2, double a3) { const int n = m_size; for (int i = 0; i < n; ++i) { mult[i] *= T(a0 - a1 * cos((2 * M_PI * i) / n) + a2 * cos((4 * M_PI * i) / n) - a3 * cos((6 * M_PI * i) / n)); } } template <typename T> std::string Window<T>::getNameForType(WindowType type) { switch (type) { case RectangularWindow: return "rectangular"; case BartlettWindow: return "bartlett"; case HammingWindow: return "hamming"; case HanningWindow: return "hanning"; case BlackmanWindow: return "blackman"; case GaussianWindow: return "gaussian"; case ParzenWindow: return "parzen"; case NuttallWindow: return "nuttall"; case BlackmanHarrisWindow: return "blackman-harris"; } std::cerr << "WARNING: Window::getNameForType: unknown type " << type << std::endl; return "unknown"; } template <typename T> WindowType Window<T>::getTypeForName(std::string name) { if (name == "rectangular") return RectangularWindow; if (name == "bartlett") return BartlettWindow; if (name == "hamming") return HammingWindow; if (name == "hanning") return HanningWindow; if (name == "blackman") return BlackmanWindow; if (name == "gaussian") return GaussianWindow; if (name == "parzen") return ParzenWindow; if (name == "nuttall") return NuttallWindow; if (name == "blackman-harris") return BlackmanHarrisWindow; std::cerr << "WARNING: Window::getTypeForName: unknown name \"" << name << "\", defaulting to \"hanning\"" << std::endl; return HanningWindow; } #endif