Method writeMidiFile

Lib/MidiFile/MidiFileWriter.cpp:7–91

#include "MidiFileWriter.h"

bool MidiFileWriter::writeMidiFile(const std::vector<Notes::Event>& inNoteEvents,
                                   const File& fileToUse,
                                   const TimeQuantizeOptions::TimeQuantizeInfo& inInfo,
                                   double inExportBpm,
                                   PitchBendModes inPitchBendMode) const
{
    // Compute offset to start at beginning of the previous bar
    const double start_offset = - inInfo.getStartLastBarSec();
    jassert(start_offset >= 0.0);

    MidiMessageSequence message_sequence;

    // Set tempo
    auto tempo_meta_event =
        MidiMessage::tempoMetaEvent(static_cast<int>(std::round(_BPMToMicrosecondsPerQuarterNote(inExportBpm))));
    tempo_meta_event.setTimeStamp(0.0);
    message_sequence.addEvent(tempo_meta_event);

    // Set time signature
    auto time_signature_meta_event =
        MidiMessage::timeSignatureMetaEvent(inInfo.timeSignatureNum, inInfo.timeSignatureDenom);
    time_signature_meta_event.setTimeStamp(0.0);
    message_sequence.addEvent(time_signature_meta_event);

    float prev_pitch_bend_semitone = 0.0f;

    // Add note events
    for (auto& note: inNoteEvents) {
        auto note_on = MidiMessage::noteOn(1, note.pitch, static_cast<float>(note.amplitude));
        note_on.setTimeStamp((note.startTime + start_offset) * inExportBpm / 60.0 * mTicksPerQuarterNote);

        auto note_off = MidiMessage::noteOff(1, note.pitch);
        note_off.setTimeStamp((note.endTime + start_offset) * inExportBpm / 60.0 * mTicksPerQuarterNote);

        message_sequence.addEvent(note_on);

        // Add pitch bend event
        if (inPitchBendMode == SinglePitchBend) {
            for (size_t i = 0; i < note.bends.size(); i++) {
                prev_pitch_bend_semitone = static_cast<float>(note.bends[i]) / 3.0f;
                auto pitch_wheel_pos = MidiMessage::pitchbendToPitchwheelPos(prev_pitch_bend_semitone, 4.0f);
                auto pitch_wheel_event = MidiMessage::pitchWheel(1, pitch_wheel_pos);
                pitch_wheel_event.setTimeStamp((note.startTime + start_offset + i * FFT_HOP / BASIC_PITCH_SAMPLE_RATE)
                                               * inExportBpm / 60.0 * mTicksPerQuarterNote);
                message_sequence.addEvent(pitch_wheel_event);
            }

            if (note.bends.empty() && prev_pitch_bend_semitone != 0) {
                prev_pitch_bend_semitone = 0.0f;
                auto pitch_wheel_pos = MidiMessage::pitchbendToPitchwheelPos(0.0f, 4.0f);
                auto pitch_wheel_event = MidiMessage::pitchWheel(1, pitch_wheel_pos);
                pitch_wheel_event.setTimeStamp((note.startTime + start_offset) * inExportBpm / 60.0
                                               * mTicksPerQuarterNote);
                message_sequence.addEvent(pitch_wheel_event);
            }
        }

        message_sequence.addEvent(note_off);