view data/model/RangeSummarisableTimeValueModel.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 2006-2007 Chris Cannam and QMUL.
    
    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 _RANGE_SUMMARISABLE_TIME_VALUE_MODEL_H_
#define _RANGE_SUMMARISABLE_TIME_VALUE_MODEL_H_

#include <QObject>

#include "DenseTimeValueModel.h"
#include "base/ZoomConstraint.h"

/**
 * Base class for models containing dense two-dimensional data (value
 * against time) that may be meaningfully represented in a zoomed view
 * using min/max range summaries.  Audio waveform data is an obvious
 * example: think "peaks and minima" for "ranges".
 */

class RangeSummarisableTimeValueModel : public DenseTimeValueModel
{
    Q_OBJECT

public:
    RangeSummarisableTimeValueModel() { }

#define RANGE_USE_SHORT 1
#ifdef RANGE_USE_SHORT
    class Range
    {
    public:
        Range() : 
            m_min(0), m_max(0), m_absmean(0) { }
        Range(const Range &r) : 
            m_min(r.m_min), m_max(r.m_max), m_absmean(r.m_absmean) { }
        Range(float min, float max, float absmean)
        { setMin(min); setMax(max); setAbsmean(absmean); }
        
        float min() const { return i2f(m_min); }
        float max() const { return i2f(m_max); }
        float absmean() const { return i2f(m_absmean); }

        void setMin(float min) { m_min = f2i(min); }
        void setMax(float max) { m_max = f2i(max); }
        void setAbsmean(float absmean) { m_absmean = f2i(absmean); }

    private:
        static inline int16_t f2i(float f) {
            if (f > 1.f) f = 1.f;
            if (f < -1.f) f = -1.f;
            return int16_t(f * 32767.f);
        }
        static inline float i2f(int16_t i) {
            return float(i) / 32767.f;
        }

        int16_t m_min;
        int16_t m_max;
        int16_t m_absmean;
    };
#else
    class Range
    {
    public:
        Range() : 
            m_min(0.f), m_max(0.f), m_absmean(0.f) { }
        Range(const Range &r) : 
            m_min(r.m_min), m_max(r.m_max), m_absmean(r.m_absmean) { }
        Range(float min, float max, float absmean) :
            m_min(min), m_max(max), m_absmean(absmean) { }

        float min() const { return m_min; }
        float max() const { return m_max; }
        float absmean() const { return m_absmean; }

        void setMin(float min) { m_min = min; }
        void setMax(float max) { m_max = max; }
        void setAbsmean(float absmean) { m_absmean = absmean; }

    private:
        float m_min;
        float m_max;
        float m_absmean;
    };
#endif

    typedef std::vector<Range> RangeBlock;

    /**
     * Return ranges from the given start frame, corresponding to the
     * given number of underlying sample frames, summarised at the
     * given block size.  duration / blockSize ranges should ideally
     * be returned.
     *
     * If the given block size is not supported by this model
     * (according to its zoom constraint), also modify the blockSize
     * parameter so as to return the block size that was actually
     * obtained.
     */
    virtual void getSummaries(size_t channel, size_t start, size_t count,
                              RangeBlock &ranges,
                              size_t &blockSize) const = 0;

    /**
     * Return the range from the given start frame, corresponding to
     * the given number of underlying sample frames, summarised at a
     * block size equal to the distance between start and end frames.
     */
    virtual Range getSummary(size_t channel, size_t start, size_t count) const = 0;

    virtual size_t getSummaryBlockSize(size_t desired) const = 0;

    QString getTypeName() const { return tr("Range-Summarisable Time-Value"); }
};

#endif