view data/fileio/MIDIFileWriter.h @ 1196:c7b9c902642f spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 2000-2007 Richard Bown and Chris Cannam
   and copyright 2007 QMUL.
*/

#ifndef _MIDI_FILE_WRITER_H_
#define _MIDI_FILE_WRITER_H_

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

#include <QString>

#include <vector>
#include <map>
#include <fstream>

class MIDIEvent;
class NoteExportable;

/**
 * Write a MIDI file.  This includes file write code for generic
 * simultaneous-track MIDI files, but the conversion stage only
 * supports a single-track MIDI file with fixed tempo, time signature
 * and timing division.
 */
class MIDIFileWriter 
{
public:
    MIDIFileWriter(QString path, 
                   const NoteExportable *exportable, 
                   sv_samplerate_t sampleRate, // used to convert exportable sample timings
                   float tempo = 120.f);
    virtual ~MIDIFileWriter();

    virtual bool isOK() const;
    virtual QString getError() const;

    virtual void write();

protected:
    typedef std::vector<MIDIEvent *> MIDITrack;
    typedef std::map<unsigned int, MIDITrack> MIDIComposition;

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

    std::string intToMIDIBytes(int number) const;
    std::string longToMIDIBytes(unsigned long number) const;
    std::string longToVarBuffer(unsigned long number) const;

    unsigned long getMIDITimeForTime(RealTime t) const;

    bool writeHeader();
    bool writeTrack(int track);
    bool writeComposition();
    
    bool convert();

    QString               m_path;
    const NoteExportable *m_exportable;
    sv_samplerate_t       m_sampleRate;
    float                 m_tempo;
    int                   m_timingDivision;   // pulses per quarter note
    MIDIFileFormatType    m_format;
    unsigned int          m_numberOfTracks;

    MIDIComposition       m_midiComposition;

    std::ofstream        *m_midiFile;
    QString               m_error;
};

#endif