Converter from `miditoolkit.midi.parser.MidiFile` to `note_seq.protobuf.music_pb2.NoteSequence`

miditoolkit_to_notesequence.py

from miditoolkit import MidiFile
from miditoolkit.midi.utils import example_midi_file
from note_seq import plot_sequence
from note_seq.protobuf.music_pb2 import NoteSequence


def miditoolkit_to_notesequence(midi: MidiFile) -> NoteSequence:
    ticks_per_sec = midi.ticks_per_beat * midi.tempo_changes[0].tempo / 60
    ticks_to_sec = lambda ticks: ticks * (1 / ticks_per_sec)
    ns = NoteSequence()
    ns.tempos.add(qpm=midi.tempo_changes[0].tempo)
    for inst in midi.instruments:
        for note in inst.notes:
            ns.notes.add(pitch=note.pitch, 
                        start_time=ticks_to_sec(note.start),
                        end_time=ticks_to_sec(note.end),
                        velocity=note.velocity,
                        is_drum=inst.is_drum,
                        # https://ja.wikipedia.org/wiki/General_MIDI
                        instrument=inst.program if inst.is_drum else 0)

    ns.total_time = ticks_to_sec(midi.max_tick)
    return ns

def check_conversion_with_plots():
    path_midi = example_midi_file()
    ns = miditoolkit_to_notesequence(path_midi)
    midi = MidiFile(path_midi)
    plot_sequence(ns)
    plot_sequence(miditoolkit_to_notesequence(midi))