# -*- coding: utf-8 -*- #/usr/bin/python2 ''' By kyubyong park. kbpark.linguist@gmail.com. https://www.github.com/kyubyong/dc_tts ''' from __future__ import print_function, division import numpy as np import librosa import os, copy import matplotlib matplotlib.use('pdf') import matplotlib.pyplot as plt from scipy import signal from hyperparams import Hyperparams as hp import tensorflow as tf def get_spectrograms(fpath): '''Parse the wave file in `fpath` and Returns normalized melspectrogram and linear spectrogram. Args: fpath: A string. The full path of a sound file. Returns: mel: A 2d array of shape (T, n_mels) and dtype of float32. mag: A 2d array of shape (T, 1+n_fft/2) and dtype of float32. ''' # Loading sound file y, sr = librosa.load(fpath, sr=hp.sr) # Trimming y, _ = librosa.effects.trim(y) # Preemphasis y = np.append(y[0], y[1:] - hp.preemphasis * y[:-1]) # stft linear = librosa.stft(y=y, n_fft=hp.n_fft, hop_length=hp.hop_length, win_length=hp.win_length) # magnitude spectrogram mag = np.abs(linear) # (1+n_fft//2, T) # mel spectrogram mel_basis = librosa.filters.mel(hp.sr, hp.n_fft, hp.n_mels) # (n_mels, 1+n_fft//2) mel = np.dot(mel_basis, mag) # (n_mels, t) # to decibel mel = 20 * np.log10(np.maximum(1e-5, mel)) mag = 20 * np.log10(np.maximum(1e-5, mag)) # normalize mel = np.clip((mel - hp.ref_db + hp.max_db) / hp.max_db, 1e-8, 1) mag = np.clip((mag - hp.ref_db + hp.max_db) / hp.max_db, 1e-8, 1) # Transpose mel = mel.T.astype(np.float32) # (T, n_mels) mag = mag.T.astype(np.float32) # (T, 1+n_fft//2) return mel, mag def spectrogram2wav(mag): '''# Generate wave file from linear magnitude spectrogram Args: mag: A numpy array of (T, 1+n_fft//2) Returns: wav: A 1-D numpy array. ''' # transpose mag = mag.T # de-noramlize mag = (np.clip(mag, 0, 1) * hp.max_db) - hp.max_db + hp.ref_db # to amplitude mag = np.power(10.0, mag * 0.05) # wav reconstruction wav = griffin_lim(mag**hp.power) # de-preemphasis wav = signal.lfilter([1], [1, -hp.preemphasis], wav) # trim wav, _ = librosa.effects.trim(wav) return wav.astype(np.float32) def griffin_lim(spectrogram): '''Applies Griffin-Lim's raw.''' X_best = copy.deepcopy(spectrogram) for i in range(hp.n_iter): X_t = invert_spectrogram(X_best) est = librosa.stft(X_t, hp.n_fft, hp.hop_length, win_length=hp.win_length) phase = est / np.maximum(1e-8, np.abs(est)) X_best = spectrogram * phase X_t = invert_spectrogram(X_best) y = np.real(X_t) return y def invert_spectrogram(spectrogram): '''Applies inverse fft. Args: spectrogram: [1+n_fft//2, t] ''' return librosa.istft(spectrogram, hp.hop_length, win_length=hp.win_length, window="hann") def plot_alignment(alignment, gs, dir=hp.logdir): """Plots the alignment. Args: alignment: A numpy array with shape of (encoder_steps, decoder_steps) gs: (int) global step. dir: Output path. """ if not os.path.exists(dir): os.mkdir(dir) fig, ax = plt.subplots() im = ax.imshow(alignment) fig.colorbar(im) plt.title('{} Steps'.format(gs)) plt.savefig('{}/alignment_{}.png'.format(dir, gs), format='png') plt.close(fig) def guided_attention(g=0.2): '''Guided attention. Refer to page 3 on the paper.''' W = np.zeros((hp.max_N, hp.max_T), dtype=np.float32) for n_pos in range(W.shape[0]): for t_pos in range(W.shape[1]): W[n_pos, t_pos] = 1 - np.exp(-(t_pos / float(hp.max_T) - n_pos / float(hp.max_N)) ** 2 / (2 * g * g)) return W def learning_rate_decay(init_lr, global_step, warmup_steps = 4000.0): '''Noam scheme from tensor2tensor''' step = tf.to_float(global_step + 1) return init_lr * warmup_steps**0.5 * tf.minimum(step * warmup_steps**-1.5, step**-0.5) def load_spectrograms(fpath): '''Read the wave file in `fpath` and extracts spectrograms''' fname = os.path.basename(fpath) mel, mag = get_spectrograms(fpath) t = mel.shape[0] # Marginal padding for reduction shape sync. num_paddings = hp.r - (t % hp.r) if t % hp.r != 0 else 0 mel = np.pad(mel, [[0, num_paddings], [0, 0]], mode="constant") mag = np.pad(mag, [[0, num_paddings], [0, 0]], mode="constant") # Reduction mel = mel[::hp.r, :] return fname, mel, mag