annotate data/fileio/MIDIFileWriter.cpp @ 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 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.
*/

#include "MIDIFileWriter.h"

#include "MIDIEvent.h"

#include "model/NoteModel.h"

#include "base/Pitch.h"

#include <algorithm>
#include <fstream>

using std::ofstream;
using std::string;
using std::ios;

using namespace MIDIConstants;

MIDIFileWriter::MIDIFileWriter(QString path, NoteModel *model, float tempo) :
    m_path(path),
    m_model(model),
    m_modelUsesHz(false),
    m_tempo(tempo)
{
    if (model->getScaleUnits().toLower() == "hz") m_modelUsesHz = true;

    if (!convert()) {
        m_error = "Conversion from model to internal MIDI format failed";
    }
}

MIDIFileWriter::~MIDIFileWriter()
{
    for (MIDIComposition::iterator i = m_midiComposition.begin();
	 i != m_midiComposition.end(); ++i) {
	
	for (MIDITrack::iterator j = i->second.begin();
	     j != i->second.end(); ++j) {
	    delete *j;
	}

	i->second.clear();
    }

    m_midiComposition.clear();
}

bool
MIDIFileWriter::isOK() const
{
    return m_error == "";
}

QString
MIDIFileWriter::getError() const
{
    return m_error;
}

void
MIDIFileWriter::write()
{
    writeComposition();
}

string
MIDIFileWriter::intToMIDIBytes(int number) const
{
    MIDIByte upper;
    MIDIByte lower;

    upper = (number & 0xFF00) >> 8;
    lower = (number & 0x00FF);

    string rv;
    rv += upper;
    rv += lower;
    return rv;
}

string
MIDIFileWriter::longToMIDIBytes(unsigned long number) const
{
    MIDIByte upper1;
    MIDIByte lower1;
    MIDIByte upper2;
    MIDIByte lower2;

    upper1 = (number & 0xff000000) >> 24;
    lower1 = (number & 0x00ff0000) >> 16;
    upper2 = (number & 0x0000ff00) >> 8;
    lower2 = (number & 0x000000ff);

    string rv;
    rv += upper1;
    rv += lower1;
    rv += upper2;
    rv += lower2;
    return rv;
}

// Turn a delta time into a MIDI time - overlapping into
// a maximum of four bytes using the MSB as the carry on
// flag.
//
string
MIDIFileWriter::longToVarBuffer(unsigned long number) const
{
    string rv;

    long inNumber = number;
    long outNumber;

    // get the lowest 7 bits of the number
    outNumber = number & 0x7f;

    // Shift and test and move the numbers
    // on if we need them - setting the MSB
    // as we go.
    //
    while ((inNumber >>= 7 ) > 0) {
        outNumber <<= 8;
        outNumber |= 0x80;
        outNumber += (inNumber & 0x7f);
    }

    // Now move the converted number out onto the buffer
    //
    while (true) {
        rv += (MIDIByte)(outNumber & 0xff);
        if (outNumber & 0x80)
            outNumber >>= 8;
        else
            break;
    }

    return rv;
}

bool
MIDIFileWriter::writeHeader()
{
    *m_midiFile << MIDI_FILE_HEADER;

    // Number of bytes in header
    *m_midiFile << (MIDIByte) 0x00;
    *m_midiFile << (MIDIByte) 0x00;
    *m_midiFile << (MIDIByte) 0x00;
    *m_midiFile << (MIDIByte) 0x06;

    // File format
    *m_midiFile << (MIDIByte) 0x00;
    *m_midiFile << (MIDIByte) m_format;

    *m_midiFile << intToMIDIBytes(m_numberOfTracks);

    *m_midiFile << intToMIDIBytes(m_timingDivision);

    return true;
}

bool
MIDIFileWriter::writeTrack(int trackNumber)
{
    bool retOK = true;
    MIDIByte eventCode = 0;
    MIDITrack::iterator midiEvent;

    // First we write into the trackBuffer, then write it out to the
    // file with its accompanying length.
    //
    string trackBuffer;

    for (midiEvent = m_midiComposition[trackNumber].begin();
         midiEvent != m_midiComposition[trackNumber].end();
         midiEvent++) {

        // Write the time to the buffer in MIDI format
        trackBuffer += longToVarBuffer((*midiEvent)->getTime());

        if ((*midiEvent)->isMeta()) {
            trackBuffer += MIDI_FILE_META_EVENT;
            trackBuffer += (*midiEvent)->getMetaEventCode();

            // Variable length number field
            trackBuffer += longToVarBuffer((*midiEvent)->
                                           getMetaMessage().length());

            trackBuffer += (*midiEvent)->getMetaMessage();
        } else {
            // Send the normal event code (with encoded channel information)
            if (((*midiEvent)->getEventCode() != eventCode) ||
                ((*midiEvent)->getEventCode() == MIDI_SYSTEM_EXCLUSIVE)) {
                trackBuffer += (*midiEvent)->getEventCode();
                eventCode = (*midiEvent)->getEventCode();
            }

            // Send the relevant data
            //
            switch ((*midiEvent)->getMessageType()) {
            case MIDI_NOTE_ON:
            case MIDI_NOTE_OFF:
            case MIDI_POLY_AFTERTOUCH:
                trackBuffer += (*midiEvent)->getData1();
                trackBuffer += (*midiEvent)->getData2();
                break;

            case MIDI_CTRL_CHANGE:
                trackBuffer += (*midiEvent)->getData1();
                trackBuffer += (*midiEvent)->getData2();
                break;

            case MIDI_PROG_CHANGE:
                trackBuffer += (*midiEvent)->getData1();
                break;

            case MIDI_CHNL_AFTERTOUCH:
                trackBuffer += (*midiEvent)->getData1();
                break;

            case MIDI_PITCH_BEND:
                trackBuffer += (*midiEvent)->getData1();
                trackBuffer += (*midiEvent)->getData2();
                break;

            case MIDI_SYSTEM_EXCLUSIVE:
                // write out message length
                trackBuffer +=
                    longToVarBuffer((*midiEvent)->getMetaMessage().length());

                // now the message
                trackBuffer += (*midiEvent)->getMetaMessage();
                break;

            default:
                break;
            }
        }
    }

    // Now we write the track - First the standard header..
    //
    *m_midiFile << MIDI_TRACK_HEADER;

    // ..now the length of the buffer..
    //
    *m_midiFile << longToMIDIBytes((long)trackBuffer.length());

    // ..then the buffer itself..
    //
    *m_midiFile << trackBuffer;

    return retOK;
}

bool
MIDIFileWriter::writeComposition()
{
    bool retOK = true;

    m_midiFile =
        new ofstream(m_path.toLocal8Bit().data(), ios::out | ios::binary);

    if (!(*m_midiFile)) {
        m_error = "Can't open file for writing.";
        delete m_midiFile;
        m_midiFile = 0;
        return false;
    }

    if (!writeHeader()) {
        retOK = false;
    }

    for (unsigned int i = 0; i < m_numberOfTracks; i++) {
        if (!writeTrack(i)) {
            retOK = false;
        }
    }

    m_midiFile->close();
    delete m_midiFile;
    m_midiFile = 0;

    if (!retOK) {
        m_error = "MIDI file write failed";
    }

    return retOK;
}

bool
MIDIFileWriter::convert()
{
    m_timingDivision = 480;
    m_format = MIDI_SINGLE_TRACK_FILE;
    m_numberOfTracks = 1;

    int track = 0;
    int midiChannel = 0;

    MIDIEvent *event;

    event = new MIDIEvent(0, MIDI_FILE_META_EVENT, MIDI_CUE_POINT,
                          "Exported from Sonic Visualiser");
    m_midiComposition[track].push_back(event);

    event = new MIDIEvent(0, MIDI_FILE_META_EVENT, MIDI_CUE_POINT,
                          "http://www.sonicvisualiser.org/");
    m_midiComposition[track].push_back(event);

    long tempoValue = long(60000000.0 / m_tempo + 0.01);
    string tempoString;
    tempoString += (MIDIByte)(tempoValue >> 16 & 0xFF);
    tempoString += (MIDIByte)(tempoValue >> 8 & 0xFF);
    tempoString += (MIDIByte)(tempoValue & 0xFF);

    event = new MIDIEvent(0, MIDI_FILE_META_EVENT, MIDI_SET_TEMPO,
                          tempoString);
    m_midiComposition[track].push_back(event);

    // Omit time signature

    const NoteModel::PointList &notes =
        static_cast<SparseModel<Note> *>(m_model)->getPoints();

    for (NoteModel::PointList::const_iterator i = notes.begin();
         i != notes.end(); ++i) {

        long frame = i->frame;
        float value = i->value;
        size_t duration = i->duration;

        int pitch;

        if (m_modelUsesHz) {
            pitch = Pitch::getPitchForFrequency(value);
        } else {
            pitch = lrintf(value);
        }

        if (pitch < 0) pitch = 0;
        if (pitch > 127) pitch = 127;

        // Convert frame to MIDI time

        double seconds = double(frame) / double(m_model->getSampleRate());
        double quarters = (seconds * m_tempo) / 60.0;
        unsigned long midiTime = lrint(quarters * m_timingDivision);

        // We don't support velocity in note models yet
        int velocity = 100;

        // Get the sounding time for the matching NOTE_OFF
        seconds = double(frame + duration) / double(m_model->getSampleRate());
        quarters = (seconds * m_tempo) / 60.0;
        unsigned long endTime = lrint(quarters * m_timingDivision);

        // At this point all the notes we insert have absolute times
        // in the delta time fields.  We resolve these into delta
        // times further down (can't do it until all the note offs are
        // in place).

        event = new MIDIEvent(midiTime,
                              MIDI_NOTE_ON | midiChannel,
                              pitch,
                              velocity);
        m_midiComposition[track].push_back(event);

        event = new MIDIEvent(endTime,
                              MIDI_NOTE_OFF | midiChannel,
                              pitch,
                              127); // loudest silence you can muster

        m_midiComposition[track].push_back(event);
    }
    
    // Now gnash through the MIDI events and turn the absolute times
    // into delta times.
    //
    for (unsigned int i = 0; i < m_numberOfTracks; i++) {

        unsigned long lastMidiTime = 0;

        // First sort the track with the MIDIEvent comparator.  Use
        // stable_sort so that events with equal times are maintained
        // in their current order.
        //
        std::stable_sort(m_midiComposition[i].begin(),
                         m_midiComposition[i].end(),
                         MIDIEventCmp());

        for (MIDITrack::iterator it = m_midiComposition[i].begin();
             it != m_midiComposition[i].end(); it++) {
            unsigned long deltaTime = (*it)->getTime() - lastMidiTime;
            lastMidiTime = (*it)->getTime();
            (*it)->setTime(deltaTime);
        }

        // Insert end of track event (delta time = 0)
        //
        event = new MIDIEvent(0, MIDI_FILE_META_EVENT,
                              MIDI_END_OF_TRACK, "");

        m_midiComposition[i].push_back(event);
    }

    return true;
}