annotate data/fileio/MIDIFileReader.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 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.
*/


/*
   This is a modified version of a source file from the 
   Rosegarden MIDI and audio sequencer and notation editor.
   This file copyright 2000-2006 Richard Bown and Chris Cannam.
*/

#ifndef _MIDI_FILE_READER_H_
#define _MIDI_FILE_READER_H_

#include "DataFileReader.h"
#include "base/RealTime.h"

#include <map>
#include <set>
#include <vector>

#include <QObject>

class MIDIEvent;

typedef unsigned char MIDIByte;

class MIDIFileImportPreferenceAcquirer // welcome to our grand marble foyer
{
public:
    enum TrackPreference {
        ImportNothing,
        ImportSingleTrack,
        MergeAllTracks,
        MergeAllNonPercussionTracks
    };

    virtual ~MIDIFileImportPreferenceAcquirer() { }

    virtual TrackPreference getTrackImportPreference
    (QStringList trackNames, bool haveSomePercussion,
     QString &singleTrack) const = 0;

    virtual void showError(QString error) = 0;
};


class MIDIFileReader : public DataFileReader
{
    Q_OBJECT

public:
    MIDIFileReader(QString path,
                   MIDIFileImportPreferenceAcquirer *pref,
                   size_t mainModelSampleRate);
    virtual ~MIDIFileReader();

    virtual bool isOK() const;
    virtual QString getError() const;
    virtual Model *load() const;

protected:
    typedef std::vector<MIDIEvent *> MIDITrack;
    typedef std::map<unsigned int, MIDITrack> MIDIComposition;
    typedef std::pair<RealTime, double> TempoChange; // time, qpm
    typedef std::map<unsigned long, TempoChange> TempoMap; // key is MIDI time

    typedef enum {
	MIDI_SINGLE_TRACK_FILE          = 0x00,
	MIDI_SIMULTANEOUS_TRACK_FILE    = 0x01,
	MIDI_SEQUENTIAL_TRACK_FILE      = 0x02,
	MIDI_FILE_BAD_FORMAT            = 0xFF
    } MIDIFileFormatType;

    bool parseFile();
    bool parseHeader(const std::string &midiHeader);
    bool parseTrack(unsigned int &trackNum);

    Model *loadTrack(unsigned int trackNum,
		     Model *existingModel = 0,
		     int minProgress = 0,
		     int progressAmount = 100) const;

    bool consolidateNoteOffEvents(unsigned int track);
    void updateTempoMap(unsigned int track);
    void calculateTempoTimestamps();
    RealTime getTimeForMIDITime(unsigned long midiTime) const;

    // Internal convenience functions
    //
    int  midiBytesToInt(const std::string &bytes);
    long midiBytesToLong(const std::string &bytes);

    long getNumberFromMIDIBytes(int firstByte = -1);

    MIDIByte getMIDIByte();
    std::string getMIDIBytes(unsigned long bytes);

    bool skipToNextTrack();

    int                    m_timingDivision;   // pulses per quarter note
    MIDIFileFormatType     m_format;
    unsigned int           m_numberOfTracks;

    long                   m_trackByteCount;
    bool                   m_decrementCount;

    std::map<int, QString> m_trackNames;
    std::set<unsigned int> m_loadableTracks;
    std::set<unsigned int> m_percussionTracks;
    MIDIComposition        m_midiComposition;
    TempoMap               m_tempoMap;

    QString                m_path;
    std::ifstream         *m_midiFile;
    size_t                 m_fileSize;
    QString                m_error;
    size_t                 m_mainModelSampleRate;

    MIDIFileImportPreferenceAcquirer *m_acquirer;
};


#endif // _MIDI_FILE_READER_H_