lib/Generator.py

import tensorflow as tf
import numpy as np
import joblib
import os
import sys

module_path = os.path.abspath(os.path.join('./lib'))

if module_path not in sys.path:
    sys.path.append(module_path)

from MusicXMLParser import MusicXMLDocument as Parser

model = tf.keras.models.load_model('./content/model.h5')
tokenizer = joblib.load("./content/tokenizer.pkl")

class Generator:
    NOTES = {
        "Cb": 11,
        "C":  0,
        "C#": 1,
        "Db": 1,
        "D":  2,
        "D#": 3,
        "Eb": 3,
        "E":  4,
        "E#": 5,
        "Fb": 4,
        "F":  5,
        "F#": 6,
        "Gb": 6,
        "G":  7,
        "G#": 8,
        "Ab": 8,
        "A": 9,
        "A#": 10,
        "Bb": 10,
        "B": 11,
        "B#": 0,
    }

    NUM_TO_NOTE = {
        0: "C",
        1: "Db",
        2: "D",
        3: "Eb",
        4: "E",
        5: "F",
        6: "Gb",
        7: "G",
        8: "Ab",
        9: "A",
        10: "Bb",
        11: "B",
        -1: "",
    }

    NUM_TO_QUALITY = {
        1: "^7",
        2: "-7",
        3: "7",
        -1: "",
    }

    def decode_tokens(self, numpy_array):
        total = []
        for i in numpy_array:
            total.append([i])
        return tokenizer.sequences_to_texts(total)

    def decode_chords(self, chords):
        res = []
        for chord in chords:
            res.append(
                Generator.NUM_TO_NOTE[chord[0]] + Generator.NUM_TO_QUALITY[chord[1]])
        return res

    def encode_chords(self, chords):
        res = []
        for chord in chords:
            if not chord:
                continue
            c = []
            if len(chord) > 2 and chord[0] + chord[1] in Generator.NOTES:
                c.append(Generator.NOTES[chord[:2]])
            else:
                c.append(Generator.NOTES[chord[0]])

            if "^" in chord or "maj" in chord:
                c.append(1)
            elif "-" in chord or "m" in chord:
                c.append(2)
            elif "7" in chord or "alt" in chord or "11" in chord:
                c.append(3)
            else:
                c.append(1)
            res.append(c)
        return res

    def generateChords(self, chordsBefore, numGenerate = 10):
        chordsBefore = self.decode_chords(self.encode_chords(chordsBefore))
        input_eval = [tokenizer.word_index[chord] for chord in chordsBefore]

        input_eval = tf.expand_dims(input_eval, 0)
        temperature = .1

        newChords = []
        for i in range(int(numGenerate)):
            predictions = model(input_eval)
            predictions = tf.squeeze(predictions, 0)
            predictions = predictions / temperature
            predicted_id = tf.random.categorical(
                predictions, num_samples=1)[-1, 0].numpy()
            input_eval = tf.expand_dims([predicted_id], 0)
            newChords.append(predicted_id)
        return self.decode_tokens(newChords)