solving mono input issue

app.py

@@ -43,7 +43,8 @@ def separate_all_stems(audio_file_path: str, model_name: str):
 
     is_mono = signal.num_channels == 1
     if is_mono:
-        signal = signal.convert_to(stereo=True)
+        signal.audio_data = signal.audio_data.repeat(2, 1)
+        signal._num_channels = 2 
 
     sr = signal.sample_rate