Allow mps device but set PYTORCH_ENABLE_MPS_FALLBACK

This is needed since the operator 'aten::unfold_backward' is not currently implemented for MPS in pytorch - see pytorch/pytorch#77764

noisereduce/spectralgate/streamed_torch_gate.py

@@ -1,37 +1,38 @@
+import os
 import torch
 from noisereduce.spectralgate.base import SpectralGate
 from noisereduce.torchgate import TorchGate as TG
 import numpy as np
 
 
 class StreamedTorchGate(SpectralGate):
-    '''
+    """
     Run interface with noisereduce.
-    '''
+    """
 
     def __init__(
-            self,
-            y,
-            sr,
-            stationary=False,
-            y_noise=None,
-            prop_decrease=1.0,
-            time_constant_s=2.0,
-            freq_mask_smooth_hz=500,
-            time_mask_smooth_ms=50,
-            thresh_n_mult_nonstationary=2,
-            sigmoid_slope_nonstationary=10,
-            n_std_thresh_stationary=1.5,
-            tmp_folder=None,
-            chunk_size=600000,
-            padding=30000,
-            n_fft=1024,
-            win_length=None,
-            hop_length=None,
-            clip_noise_stationary=True,
-            use_tqdm=False,
-            n_jobs=1,
-            device="cuda",
+        self,
+        y,
+        sr,
+        stationary=False,
+        y_noise=None,
+        prop_decrease=1.0,
+        time_constant_s=2.0,
+        freq_mask_smooth_hz=500,
+        time_mask_smooth_ms=50,
+        thresh_n_mult_nonstationary=2,
+        sigmoid_slope_nonstationary=10,
+        n_std_thresh_stationary=1.5,
+        tmp_folder=None,
+        chunk_size=600000,
+        padding=30000,
+        n_fft=1024,
+        win_length=None,
+        hop_length=None,
+        clip_noise_stationary=True,
+        use_tqdm=False,
+        n_jobs=1,
+        device="cuda",
     ):
         super().__init__(
             y=y,
@@ -50,7 +51,14 @@ def __init__(
             n_jobs=n_jobs,
         )
 
-        self.device = torch.device(device if torch.cuda.is_available() else 'cpu')
+        if device == "cuda" and not torch.cuda.is_available():
+            device = "cpu"
+        elif device == "mps":
+            os.environ["PYTORCH_ENABLE_MPS_FALLBACK"] = "1"
+        else:
+            device = "cpu"
+
+        self.device = torch.device(device)
 
         # noise convert to torch if needed
         if y_noise is not None: