Handle stereo files in case those are provided

vc_service_request.py

@@ -33,6 +33,10 @@ def prepare_audio(audio: Tuple[int, np.ndarray]) -> np.ndarray:
         mult = 32767.0 if np.max(np.abs(wav)) <= 1.0 else 1.0
         wav = (wav * mult).astype(np.int16)
 
+    if wav.ndim == 2:
+        # average channels
+        wav = np.mean(wav, axis=0, keepdims=False)
+        
     # ensure proper sampling rate
     if sr != 16000:
         wav = (wav / 32768.0).astype(np.float)