refactor(audio.processor): remove duplicate stft+griffin_lim

TTS/utils/audio/processor.py

@@ -8,7 +8,7 @@ import scipy.signal
 import soundfile as sf
 
 from TTS.tts.utils.helpers import StandardScaler
-from TTS.utils.audio.numpy_transforms import compute_f0
+from TTS.utils.audio.numpy_transforms import compute_f0, stft, griffin_lim
 
 # pylint: disable=too-many-public-methods
 
@@ -460,9 +460,14 @@ class AudioProcessor(object):
             np.ndarray: Spectrogram.
         """
         if self.preemphasis != 0:
-            D = self._stft(self.apply_preemphasis(y))
-        else:
-            D = self._stft(y)
+            y = self.apply_preemphasis(y)
+        D = stft(
+            y=y,
+            fft_size=self.fft_size,
+            hop_length=self.hop_length,
+            win_length=self.win_length,
+            pad_mode=self.stft_pad_mode,
+        )
         if self.do_amp_to_db_linear:
             S = self._amp_to_db(np.abs(D))
         else:
@@ -472,9 +477,14 @@ class AudioProcessor(object):
     def melspectrogram(self, y: np.ndarray) -> np.ndarray:
         """Compute a melspectrogram from a waveform."""
         if self.preemphasis != 0:
-            D = self._stft(self.apply_preemphasis(y))
-        else:
-            D = self._stft(y)
+            y = self.apply_preemphasis(y)
+        D = stft(
+            y=y,
+            fft_size=self.fft_size,
+            hop_length=self.hop_length,
+            win_length=self.win_length,
+            pad_mode=self.stft_pad_mode,
+        )
         if self.do_amp_to_db_mel:
             S = self._amp_to_db(self._linear_to_mel(np.abs(D)))
         else:
@@ -486,18 +496,16 @@ class AudioProcessor(object):
         S = self.denormalize(spectrogram)
         S = self._db_to_amp(S)
         # Reconstruct phase
-        if self.preemphasis != 0:
-            return self.apply_inv_preemphasis(self._griffin_lim(S**self.power))
-        return self._griffin_lim(S**self.power)
+        W = self._griffin_lim(S**self.power)
+        return self.apply_inv_preemphasis(W) if self.preemphasis != 0 else W
 
     def inv_melspectrogram(self, mel_spectrogram: np.ndarray) -> np.ndarray:
         """Convert a melspectrogram to a waveform using Griffi-Lim vocoder."""
         D = self.denormalize(mel_spectrogram)
         S = self._db_to_amp(D)
         S = self._mel_to_linear(S)  # Convert back to linear
-        if self.preemphasis != 0:
-            return self.apply_inv_preemphasis(self._griffin_lim(S**self.power))
-        return self._griffin_lim(S**self.power)
+        W = self._griffin_lim(S**self.power)
+        return self.apply_inv_preemphasis(W) if self.preemphasis != 0 else W
 
     def out_linear_to_mel(self, linear_spec: np.ndarray) -> np.ndarray:
         """Convert a full scale linear spectrogram output of a network to a melspectrogram.
@@ -515,45 +523,16 @@ class AudioProcessor(object):
         mel = self.normalize(S)
         return mel
 
-    ### STFT and ISTFT ###
-    def _stft(self, y: np.ndarray) -> np.ndarray:
-        """Librosa STFT wrapper.
-
-        Args:
-            y (np.ndarray): Audio signal.
-
-        Returns:
-            np.ndarray: Complex number array.
-        """
-        return librosa.stft(
-            y=y,
-            n_fft=self.fft_size,
+    def _griffin_lim(self, S):
+        return griffin_lim(
+            spec=S,
+            num_iter=self.griffin_lim_iters,
             hop_length=self.hop_length,
             win_length=self.win_length,
+            fft_size=self.fft_size,
             pad_mode=self.stft_pad_mode,
-            window="hann",
-            center=True,
         )
 
-    def _istft(self, y: np.ndarray) -> np.ndarray:
-        """Librosa iSTFT wrapper."""
-        return librosa.istft(y, hop_length=self.hop_length, win_length=self.win_length)
-
-    def _griffin_lim(self, S):
-        angles = np.exp(2j * np.pi * np.random.rand(*S.shape))
-        try:
-            S_complex = np.abs(S).astype(np.complex)
-        except AttributeError:  # np.complex is deprecated since numpy 1.20.0
-            S_complex = np.abs(S).astype(complex)
-        y = self._istft(S_complex * angles)
-        if not np.isfinite(y).all():
-            print(" [!] Waveform is not finite everywhere. Skipping the GL.")
-            return np.array([0.0])
-        for _ in range(self.griffin_lim_iters):
-            angles = np.exp(1j * np.angle(self._stft(y)))
-            y = self._istft(S_complex * angles)
-        return y
-
     def compute_stft_paddings(self, x, pad_sides=1):
         """Compute paddings used by Librosa's STFT. Compute right padding (final frame) or both sides padding
         (first and final frames)"""

tests/vocoder_tests/test_vocoder_losses.py

@@ -5,6 +5,7 @@ import torch
 from tests import get_tests_input_path, get_tests_output_path, get_tests_path
 from TTS.config import BaseAudioConfig
 from TTS.utils.audio import AudioProcessor
+from TTS.utils.audio.numpy_transforms import stft
 from TTS.vocoder.layers.losses import MelganFeatureLoss, MultiScaleSTFTLoss, STFTLoss, TorchSTFT
 
 TESTS_PATH = get_tests_path()
@@ -21,7 +22,7 @@ def test_torch_stft():
     torch_stft = TorchSTFT(ap.fft_size, ap.hop_length, ap.win_length)
     # librosa stft
     wav = ap.load_wav(WAV_FILE)
-    M_librosa = abs(ap._stft(wav))  # pylint: disable=protected-access
+    M_librosa = abs(stft(y=wav, fft_size=ap.fft_size, hop_length=ap.hop_length, win_length=ap.win_length))
     # torch stft
     wav = torch.from_numpy(wav[None, :]).float()
     M_torch = torch_stft(wav)