default to cpu for testing

webui.py

@@ -25,7 +25,7 @@ from sparktts.utils.token_parser import LEVELS_MAP_UI
 from huggingface_hub import snapshot_download
 
 
-def initialize_model(model_dir=None, device=0):
+def initialize_model(model_dir=None, device="cpu"):
     """Load the model once at the beginning."""
     
     if model_dir is None:
@@ -33,7 +33,7 @@ def initialize_model(model_dir=None, device=0):
         model_dir = snapshot_download("SparkAudio/Spark-TTS-0.5B", local_dir="pretrained_models/Spark-TTS-0.5B")
         
     logging.info(f"Loading model from: {model_dir}")
-    device = torch.device(f"cuda:{device}")
+    device = torch.device(device)
     model = SparkTTS(model_dir, device)
     return model
 
@@ -224,9 +224,9 @@ def parse_arguments():
     )
     parser.add_argument(
         "--device",
-        type=int,
-        default=0,
-        help="ID of the GPU device to use (e.g., 0 for cuda:0)."
+        type=str,
+        default="cpu",
+        help="Device to use (e.g., 'cpu' or 'cuda:0')."
     )
     parser.add_argument(
         "--server_name",