annotate data/fft/FFTMemoryCache.h @ 490:c3fb8258e34d

* Make it possible to import an entire session from an RDF document.
  However, at the moment the timings of events appear to be constrained
  by how far the audio decoder has got through its audio file at the
  time the event is queried -- need to investigate.

/* -*- 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"
#include "base/Profiler.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:
    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 {
        if (m_storageType == Rectangular) {
            Profiler profiler("FFTMemoryCache::getMagnitudeAt: cart to polar");
            return sqrt(m_freal[x][y] * m_freal[x][y] +
                        m_fimag[x][y] * m_fimag[x][y]);
        } else {
            return getNormalizedMagnitudeAt(x, y) * m_factor[x];
        }
    }
    
    virtual float getNormalizedMagnitudeAt(size_t x, size_t y) const {
        if (m_storageType == Rectangular) return getMagnitudeAt(x, y) / m_factor[x];
        else 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 == Rectangular) {
            Profiler profiler("FFTMemoryCache::getValuesAt: cart to polar");
            return atan2f(m_fimag[x][y], m_freal[x][y]);
        } else if (m_storageType == Polar) {
            return m_fphase[x][y];
        } else {
            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 {
        if (m_storageType == Rectangular) {
            real = m_freal[x][y];
            imag = m_fimag[x][y];
        } else {
            Profiler profiler("FFTMemoryCache::getValuesAt: polar to cart");
            float mag = getMagnitudeAt(x, y);
            float phase = getPhaseAt(x, y);
            real = mag * cosf(phase);
            imag = mag * sinf(phase);
        }
    }

    virtual bool haveSetColumnAt(size_t x) const {
        return m_colset.get(x);
    }

    virtual void setColumnAt(size_t x, float *mags, float *phases, float factor);

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

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

    virtual StorageType getStorageType() { return m_storageType; }
    virtual Type getType() { return MemoryCache; }

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_freal;
    float **m_fimag;
    float *m_factor;
    StorageType m_storageType;
    ResizeableBitset m_colset;

    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));
        }
    }

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


#endif