format_conversions.py

import copy
import os
from pathlib import Path

from music21 import converter, musicxml, stream, note, chord, clef
import verovio
import shutil
import subprocess
from pydub import AudioSegment

BASE_DIR = os.path.dirname(os.path.abspath(__file__))

class Format_Converter:

    def midi_to_musicxml_string_two_staves(midi_path, split_pitch=60):
        score = converter.parse(midi_path)
        merged = score.flatten()
        treble = stream.Part()
        bass = stream.Part()
        treble.insert(0, clef.TrebleClef())
        bass.insert(0, clef.BassClef())

        for el in merged.recurse().notesAndRests:
            true_offset = el.getOffsetInHierarchy(score)

            if isinstance(el, note.Rest):
                treble.insert(true_offset, copy.deepcopy(el))
                bass.insert(true_offset, copy.deepcopy(el))

            elif isinstance(el, note.Note):
                target = treble if el.pitch.midi >= split_pitch else bass
                target.insert(true_offset, copy.deepcopy(el))

            elif isinstance(el, chord.Chord):
                treble_pitches = [p for p in el.pitches if p.midi >= split_pitch]
                bass_pitches = [p for p in el.pitches if p.midi < split_pitch]

                if treble_pitches:
                    treble_chord = chord.Chord(treble_pitches)
                    treble_chord.quarterLength = el.quarterLength
                    treble_chord.volume = el.volume
                    treble.insert(true_offset, treble_chord)

                if bass_pitches:
                    bass_chord = chord.Chord(bass_pitches)
                    bass_chord.quarterLength = el.quarterLength
                    bass_chord.volume = el.volume
                    bass.insert(true_offset, bass_chord)

        final_score = stream.Score()
        final_score.insert(0, treble)  # order: top staff first
        final_score.insert(0, bass)

        exporter = musicxml.m21ToXml.GeneralObjectExporter(final_score)
        musicxml_str = exporter.parse().decode('utf-8')
        return musicxml_str

    @classmethod
    def midi_to_musicxml_string(cls, midi_path):
        # Parse MIDI file into a music21 stream
        score = converter.parse(midi_path)
        # Export to MusicXML string
        exporter = musicxml.m21ToXml.GeneralObjectExporter(score)
        return exporter.parse().decode('utf-8')  # parse() returns bytes

    @classmethod
    def xml_to_svg_file(cls, tk, musicxml, output_file):
        try:
            mei_str = cls.xml_to_mei_string(tk, musicxml)
            # Load MEI and render SVG
            tk.loadData(mei_str)
            svg = tk.renderToSVGFile(output_file)
            return output_file
        except Exception as e:
            print("error in midi_to_svg_file")
            # return f"<p style='color:red'>Error: {e}</p>"
            return output_file

    @classmethod
    def midi_to_svg_file(cls, tk, midi_path, output_file):
        musicxml = cls.midi_to_musicxml_string_two_staves(midi_path)
        return cls.xml_to_svg_file(tk, musicxml, output_file)

    @classmethod
    def xml_to_mei_string(cls, tk, xmlstring):
        tk.loadData(xmlstring)
        return tk.getMEI()

    @classmethod
    def midi_to_svg(cls, tk, midi_path):
        try:
            # Convert MIDI to MEI using music21
            musicxmlobj = cls.midi_to_musicxml_string(midi_path)
            mei_str = cls.xml_to_mei_string(tk, musicxmlobj)
            # Load MEI and render SVG
            tk.loadData(mei_str)
            svg = tk.renderToSVG(1)
            return svg
        except Exception as e:
            return f"<p style='color:red'>Error: {e}</p>"



    @classmethod
    def m21_to_xml(cls, m21):
        # Export to MusicXML string
        exporter = musicxml.m21ToXml.GeneralObjectExporter()
        return exporter.parse(m21).decode('utf-8')

    @classmethod
    def m21_to_svg_file(cls, m21, output_file):
        # Export to MusicXML string
        exporter = musicxml.m21ToXml.GeneralObjectExporter()
        musicxmlobj = exporter.parse(m21).decode('utf-8')
        try:
            tk = verovio.toolkit()
            mei_str = cls.xml_to_mei_string(tk, musicxmlobj)
            # Load MEI and render SVG
            tk.loadData(mei_str)
            svg = tk.renderToSVGFile(output_file)
            return output_file
        except Exception as e:
            print("error in midi_to_svg_file")
            # return f"<p style='color:red'>Error: {e}</p>"
            return output_file

    def convert_midi_to_audio(self, midi_path, file_name):
        if not shutil.which("fluidsynth"):
            try:
                subprocess.run(["apt-get", "update"], check=True)
                subprocess.run(["apt-get", "install", "-y", "fluidsynth"], check=True)
            except Exception as e:
                return f"Error installing Fluidsynth: {str(e)}"
        wav_path = os.path.join(BASE_DIR, file_name + ".wav")
        mp3_path = os.path.join(BASE_DIR, file_name + ".mp3")
        soundfont_path = os.path.join(BASE_DIR, "soundfont.sf2")
        if not os.path.exists(soundfont_path):
            return "Error: SoundFont file not found. Please provide a valid .sf2 file."
        try:
            subprocess.run(["fluidsynth", "-ni", soundfont_path, midi_path, "-F", wav_path, "-r", "44100"], check=True)
            AudioSegment.converter = "ffmpeg"
            audio = AudioSegment.from_wav(wav_path)
            audio.export(mp3_path, format="mp3")
            return mp3_path
        except Exception as e:
            return f"Error converting MIDI to audio: {str(e)}"

def musescore_midi_to_svg(midi_path, svg_path, mscore_path="/Applications/MuseScore 4.app/Contents/MacOS/mscore"):
    subprocess.run([mscore_path, midi_path, "-o", svg_path, "-T"], check=True)

def musescore_midi_to_musicxml(
        midi_path: str,
        output_path: str = None,
        musescore_path: str = "/Applications/MuseScore 4.app/Contents/MacOS/mscore"
):
    midi_file = Path(midi_path)
    if not midi_file.exists():
        raise FileNotFoundError(f"MIDI file not found: {midi_path}")

    if output_path is None:
        output_path = midi_file.with_suffix(".musicxml")
    else:
        output_path = Path(output_path)

    command = [musescore_path, str(midi_file), "-o", str(output_path)]
    try:
        result = subprocess.run(command, capture_output=True, text=True, check=True)
        print("✅ MuseScore conversion successful.")
        print(f"➡️ Output: {output_path}")
    except subprocess.CalledProcessError as e:
        print("❌ MuseScore conversion failed.")
        print("stderr:", e.stderr)
        print("stdout:", e.stdout)
        raise

if __name__ == '__main__':
    svg_string = Format_Converter().midi_to_svg(verovio.toolkit(), 'output.mid')