Update app.py

app.py

@@ -6,6 +6,7 @@ import soundfile as sf
 from audiosr import build_model, super_resolution, save_wave
 import tempfile
 import numpy as np
+import os
 
 # Set MPS device if available (for Mac M-Series GPUs)
 device = "cuda" if torch.cuda.is_available() else "cpu"