librosaのGriffin-Limアルゴリズムで無矛盾位相復元

feat_librosa_gla.py

#!/usr/bin/env python3

# MIT License

# Copyright (C) 2020 by Akira TAMAMORI

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# Commentary:
# - Griffin-Lim法により位相を復元する

import numpy as np
from scipy.io import wavfile
import librosa

IN_WAVE_FILE = "in.wav"  # モノラル音声
OUT_WAVE_FILE = "out_librosa_gla.wav"  # 復元音声

FRAME_LENGTH = 1024             # フレーム長 (FFTサイズ)
HOP_LENGTH = 80                 # フレームのシフト長

ITERATION = 200                 # Griffin-Lim法における位相推定の最大繰り返し数

# 音声のロード
fs, data = wavfile.read(IN_WAVE_FILE)
data = data.astype(np.float64)

# 振幅スペクトル（位相復元なので手に入るのはこれのみ）
amp_spec = np.abs(librosa.core.stft(data, n_fft=FRAME_LENGTH,
                                    hop_length=HOP_LENGTH,
                                    win_length=FRAME_LENGTH))

# Griffin-Lim法により位相復元した音声
recovered = librosa.griffinlim(amp_spec, n_iter=ITERATION,
                               hop_length=HOP_LENGTH, random_state=0)
recovered = recovered.astype(np.int16)

# 復元された音声をwavファイルとして保存
wavfile.write(OUT_WAVE_FILE, fs, recovered)