view data/fft/FFTMemoryCache.h @ 316:3a6725f285d6

* Make RemoteFile far more pervasive, and use it for local files as well
  so that we can handle both transparently.  Make it shallow copy with
  reference counting, so it can be used by value without having to worry
  about the cache file lifetime.  Use RemoteFile for MainWindow file-open
  functions, etc

/* -*- 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 _FFT_MEMORY_CACHE_H_
#define _FFT_MEMORY_CACHE_H_

#include "FFTCache.h"

#include "base/ResizeableBitset.h"

/**
 * In-memory FFT cache.  For this we want to cache magnitude with
 * enough resolution to have gain applied afterwards and determine
 * whether something is a peak or not, and also cache phase rather
 * than only phase-adjusted frequency so that we don't have to
 * recalculate if switching between phase and magnitude displays.  At
 * the same time, we don't want to take up too much memory.  It's not
 * expected to be accurate enough to be used as input for DSP or
 * resynthesis code.
 *
 * This implies probably 16 bits for a normalized magnitude and at
 * most 16 bits for phase.
 *
 * Each column's magnitudes are expected to be stored normalized
 * to [0,1] with respect to the column, so the normalization
 * factor should be calculated before all values in a column, and
 * set appropriately.
 */

class FFTMemoryCache : public FFTCache
{
public:
    enum StorageType {
        Compact, // 16 bits normalized polar
        Polar, // floating point mag+phase
    };

    FFTMemoryCache(StorageType storageType); // of size zero, call resize() before using
    virtual ~FFTMemoryCache();
	
    virtual size_t getWidth() const { return m_width; }
    virtual size_t getHeight() const { return m_height; }
	
    virtual void resize(size_t width, size_t height);
    virtual void reset(); // zero-fill or 1-fill as appropriate without changing size
    
    virtual float getMagnitudeAt(size_t x, size_t y) const {
        return getNormalizedMagnitudeAt(x, y) * m_factor[x];
    }
    
    virtual float getNormalizedMagnitudeAt(size_t x, size_t y) const {
        if (m_storageType == Polar) return m_fmagnitude[x][y];
        else return float(m_magnitude[x][y]) / 65535.0;
    }
    
    virtual float getMaximumMagnitudeAt(size_t x) const {
        return m_factor[x];
    }
    
    virtual float getPhaseAt(size_t x, size_t y) const {
        if (m_storageType == Polar) return m_fphase[x][y];
        int16_t i = (int16_t)m_phase[x][y];
        return (float(i) / 32767.0) * M_PI;
    }
    
    virtual void getValuesAt(size_t x, size_t y, float &real, float &imag) const {
        float mag = getMagnitudeAt(x, y);
        float phase = getPhaseAt(x, y);
        real = mag * cosf(phase);
        imag = mag * sinf(phase);
    }

    virtual void setNormalizationFactor(size_t x, float factor) {
        if (x < m_width) m_factor[x] = factor;
    }
    
    virtual void setMagnitudeAt(size_t x, size_t y, float mag) {
         // norm factor must already be set
        setNormalizedMagnitudeAt(x, y, mag / m_factor[x]);
    }
    
    virtual void setNormalizedMagnitudeAt(size_t x, size_t y, float norm) {
        if (x < m_width && y < m_height) {
            if (m_storageType == Polar) m_fmagnitude[x][y] = norm;
            else m_magnitude[x][y] = uint16_t(norm * 65535.0);
        }
    }
    
    virtual void setPhaseAt(size_t x, size_t y, float phase) {
        // phase in range -pi -> pi
        if (x < m_width && y < m_height) {
            if (m_storageType == Polar) m_fphase[x][y] = phase;
            else m_phase[x][y] = uint16_t(int16_t((phase * 32767) / M_PI));
        }
    }
    
    virtual bool haveSetColumnAt(size_t x) const {
        return m_colset.get(x);
    }

    virtual void setColumnAt(size_t x, float *mags, float *phases, float factor) {
        setNormalizationFactor(x, factor);
        for (size_t y = 0; y < m_height; ++y) {
            setMagnitudeAt(x, y, mags[y]);
            setPhaseAt(x, y, phases[y]);
        }
        m_colset.set(x);
    }

    virtual void setColumnAt(size_t x, float *reals, float *imags);

    static size_t getCacheSize(size_t width, size_t height, StorageType type);

private:
    size_t m_width;
    size_t m_height;
    uint16_t **m_magnitude;
    uint16_t **m_phase;
    float **m_fmagnitude;
    float **m_fphase;
    float *m_factor;
    StorageType m_storageType;
    ResizeableBitset m_colset;

    void resize(uint16_t **&, size_t, size_t);
    void resize(float **&, size_t, size_t);
};


#endif