update mulaw decoder

utils/audio.py

@@ -218,25 +218,22 @@ class AudioProcessor(object):
         return librosa.effects.trim(
             wav, top_db=40, frame_length=1024, hop_length=256)[0]
 
-    # WaveRNN repo specific functions
-    # def mulaw_encode(self, wav, qc):
-    #     mu = qc - 1
-    #     wav_abs = np.minimum(np.abs(wav), 1.0)
-    #     magnitude = np.log(1 + mu * wav_abs) / np.log(1. + mu)
-    #     signal = np.sign(wav) * magnitude
-    #     # Quantize signal to the specified number of levels.
-    #     signal = (signal + 1) / 2 * mu + 0.5
-    #     return signal.astype(np.int32)
+    @staticmethod
+    def mulaw_encode(wav, qc):
+        mu = 2 ** qc - 1
+        # wav_abs = np.minimum(np.abs(wav), 1.0)
+        signal = np.sign(wav) * np.log(1 + mu * np.abs(wav)) / np.log(1. + mu)
+        # Quantize signal to the specified number of levels.
+        signal = (signal + 1) / 2 * mu + 0.5
+        return np.floor(signal,)
 
-    # def mulaw_decode(self, wav, qc):
-    #     """Recovers waveform from quantized values."""
-    #     mu = qc - 1
-    #     # Map values back to [-1, 1].
-    #     casted = wav.astype(np.float32)
-    #     signal = 2 * (casted / mu) - 1
-    #     # Perform inverse of mu-law transformation.
-    #     magnitude = (1 / mu) * ((1 + mu) ** abs(signal) - 1)
-    #     return np.sign(signal) * magnitude
+    @staticmethod
+    def mulaw_decode(wav, qc):
+        """Recovers waveform from quantized values."""
+        mu = 2 ** qc - 1
+        mu = mu - 1
+        signal = np.sign(wav) / mu * ((1 + mu) ** np.abs(wav) - 1)
+        return signal
 
     def load_wav(self, filename, encode=False):
         x, sr = sf.read(filename)