Chris@87: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@87: 
Chris@87: /*
Chris@87:     Sonic Visualiser
Chris@87:     An audio file viewer and annotation editor.
Chris@87:     Centre for Digital Music, Queen Mary, University of London.
Chris@87:     This file copyright 2006 Chris Cannam.
Chris@87:     
Chris@87:     This program is free software; you can redistribute it and/or
Chris@87:     modify it under the terms of the GNU General Public License as
Chris@87:     published by the Free Software Foundation; either version 2 of the
Chris@87:     License, or (at your option) any later version.  See the file
Chris@87:     COPYING included with this distribution for more information.
Chris@87: */
Chris@87: 
Chris@87: #ifndef _FFT_CACHE_H_
Chris@87: #define _FFT_CACHE_H_
Chris@87: 
Chris@90: #include <cstdlib>
Chris@90: #include <cmath>
Chris@90: 
Chris@87: #include <stdint.h>
Chris@87: 
Chris@87: class FFTCacheBase
Chris@87: {
Chris@87: public:
Chris@87:     virtual ~FFTCacheBase() { }
Chris@87: 
Chris@87:     virtual size_t getWidth() const = 0;
Chris@87:     virtual size_t getHeight() const = 0;
Chris@87: 	
Chris@87:     virtual void resize(size_t width, size_t height) = 0;
Chris@87:     virtual void reset() = 0; // zero-fill or 1-fill as appropriate without changing size
Chris@87: 	
Chris@87:     virtual float getMagnitudeAt(size_t x, size_t y) const = 0;
Chris@87:     virtual float getNormalizedMagnitudeAt(size_t x, size_t y) const = 0;
Chris@87:     virtual float getPhaseAt(size_t x, size_t y) const = 0;
Chris@87: 
Chris@108:     virtual bool haveColumnAt(size_t x) const = 0;
Chris@90:     virtual void setColumnAt(size_t x, float *mags, float *phases, float factor) = 0;
Chris@90: 
Chris@90:     bool isLocalPeak(size_t x, size_t y) const {
Chris@90:         float mag = getMagnitudeAt(x, y);
Chris@90:         if (y > 0 && mag < getMagnitudeAt(x, y - 1)) return false;
Chris@90:         if (y < getHeight()-1 && mag < getMagnitudeAt(x, y + 1)) return false;
Chris@90:         return true;
Chris@90:     }
Chris@90:     bool isOverThreshold(size_t x, size_t y, float threshold) const {
Chris@90:         return getMagnitudeAt(x, y) > threshold;
Chris@90:     }
Chris@87: 
Chris@87: protected:
Chris@87:     FFTCacheBase() { }
Chris@87: };
Chris@87: 
Chris@87: 
Chris@87: /**
Chris@87:  * For the in-memory FFT cache, we would like to cache magnitude with
Chris@87:  * enough resolution to have gain applied afterwards and determine
Chris@87:  * whether something is a peak or not, and also cache phase rather
Chris@87:  * than only phase-adjusted frequency so that we don't have to
Chris@87:  * recalculate if switching between phase and magnitude displays.  At
Chris@87:  * the same time, we don't want to take up too much memory.  It's not
Chris@87:  * expected to be accurate enough to be used as input for DSP or
Chris@87:  * resynthesis code.
Chris@87:  *
Chris@87:  * This implies probably 16 bits for a normalized magnitude and at
Chris@87:  * most 16 bits for phase.
Chris@87:  *
Chris@87:  * Each column's magnitudes are expected to be stored normalized
Chris@87:  * to [0,1] with respect to the column, so the normalization
Chris@87:  * factor should be calculated before all values in a column, and
Chris@87:  * set appropriately.
Chris@87:  */
Chris@87: 
Chris@87: class FFTMemoryCache : public FFTCacheBase
Chris@87: {
Chris@87: public:
Chris@87:     FFTMemoryCache(); // of size zero, call resize() before using
Chris@87:     virtual ~FFTMemoryCache();
Chris@87: 	
Chris@87:     virtual size_t getWidth() const { return m_width; }
Chris@87:     virtual size_t getHeight() const { return m_height; }
Chris@87: 	
Chris@87:     virtual void resize(size_t width, size_t height);
Chris@87:     virtual void reset(); // zero-fill or 1-fill as appropriate without changing size
Chris@87:     
Chris@87:     virtual float getMagnitudeAt(size_t x, size_t y) const {
Chris@87:         return getNormalizedMagnitudeAt(x, y) * m_factor[x];
Chris@87:     }
Chris@87:     
Chris@87:     virtual float getNormalizedMagnitudeAt(size_t x, size_t y) const {
Chris@87:         return float(m_magnitude[x][y]) / 65535.0;
Chris@87:     }
Chris@87:     
Chris@87:     virtual float getPhaseAt(size_t x, size_t y) const {
Chris@87:         int16_t i = (int16_t)m_phase[x][y];
Chris@87:         return (float(i) / 32767.0) * M_PI;
Chris@87:     }
Chris@87:     
Chris@87:     virtual void setNormalizationFactor(size_t x, float factor) {
Chris@87:         if (x < m_width) m_factor[x] = factor;
Chris@87:     }
Chris@87:     
Chris@87:     virtual void setMagnitudeAt(size_t x, size_t y, float mag) {
Chris@87:          // norm factor must already be set
Chris@87:         setNormalizedMagnitudeAt(x, y, mag / m_factor[x]);
Chris@87:     }
Chris@87:     
Chris@87:     virtual void setNormalizedMagnitudeAt(size_t x, size_t y, float norm) {
Chris@87:         if (x < m_width && y < m_height) {
Chris@87:             m_magnitude[x][y] = uint16_t(norm * 65535.0);
Chris@87:         }
Chris@87:     }
Chris@87:     
Chris@87:     virtual void setPhaseAt(size_t x, size_t y, float phase) {
Chris@87:         // phase in range -pi -> pi
Chris@87:         if (x < m_width && y < m_height) {
Chris@87:             m_phase[x][y] = uint16_t(int16_t((phase * 32767) / M_PI));
Chris@87:         }
Chris@87:     }
Chris@87:     
Chris@108:     virtual bool haveColumnAt(size_t x) const {
Chris@108:         return true;
Chris@108:     }
Chris@108: 
Chris@90:     virtual void setColumnAt(size_t x, float *mags, float *phases, float factor) {
Chris@90:         setNormalizationFactor(x, factor);
Chris@90:         for (size_t y = 0; y < m_height; ++y) {
Chris@90:             setMagnitudeAt(x, y, mags[y]);
Chris@90:             setPhaseAt(x, y, phases[y]);
Chris@90:         }
Chris@87:     }
Chris@90: 
Chris@87: private:
Chris@87:     size_t m_width;
Chris@87:     size_t m_height;
Chris@87:     uint16_t **m_magnitude;
Chris@87:     uint16_t **m_phase;
Chris@87:     float *m_factor;
Chris@90: 
Chris@87:     void resize(uint16_t **&, size_t, size_t);
Chris@87: };
Chris@87: 
Chris@87: #endif