Print helpful error message if models not found (#416)

demo_cli.py

 from encoder.params_model import model_embedding_size as speaker_embedding_size
 from utils.argutils import print_args
+from utils.modelutils import check_model_paths
 from synthesizer.inference import Synthesizer
 from encoder import inference as encoder
 from vocoder import inference as vocoder
@@ -53,6 +54,9 @@ if __name__ == '__main__':
     else:
         print("Using CPU for inference.\n")
     
+    ## Remind the user to download pretrained models if needed
+    check_model_paths(encoder_path=args.enc_model_fpath, synthesizer_path=args.syn_model_dir,
+                      vocoder_path=args.voc_model_fpath)
     
     ## Load the models one by one.
     print("Preparing the encoder, the synthesizer and the vocoder...")

demo_toolbox.py

 from pathlib import Path
 from toolbox import Toolbox
 from utils.argutils import print_args
+from utils.modelutils import check_model_paths
 import argparse
 
 
@@ -26,8 +27,11 @@ if __name__ == '__main__':
         "If True, the memory used by the synthesizer will be freed after each use. Adds large "
         "overhead but allows to save some GPU memory for lower-end GPUs.")
     args = parser.parse_args()
+    print_args(args, parser)
+
+    ## Remind the user to download pretrained models if needed
+    check_model_paths(encoder_path=args.enc_models_dir, synthesizer_path=args.syn_models_dir,
+                      vocoder_path=args.voc_models_dir)
 
     # Launch the toolbox
-    print_args(args, parser)
-    Toolbox(**vars(args))
-    
\ No newline at end of file
+    Toolbox(**vars(args))    

utils/modelutils.py

+from pathlib import Path
+
+def check_model_paths(encoder_path: Path, synthesizer_path: Path, vocoder_path: Path):
+    # This function tests the model paths and makes sure at least one is valid.
+    if encoder_path.is_file() or encoder_path.is_dir():
+        return
+    if synthesizer_path.is_file() or synthesizer_path.is_dir():
+        return
+    if vocoder_path.is_file() or vocoder_path.is_dir():
+        return
+
+    # If none of the paths exist, remind the user to download models if needed
+    print("Error: Model files not found. If needed, download them here:")
+    print("https://github.com/CorentinJ/Real-Time-Voice-Cloning/wiki/Pretrained-models\n")
+    quit(-1)