Fix API file path handling for predict_json endpoint

app.py

@@ -209,8 +209,19 @@ def predict_tone_json(audio_file):
         }
 
     try:
+        # Handle different input types from Gradio API
+        # audio_file can be: string path, dict with 'path' key, or other formats
+        if isinstance(audio_file, dict):
+            # FileData format from API
+            file_path = audio_file.get('path', audio_file.get('name', str(audio_file)))
+        elif isinstance(audio_file, str):
+            file_path = audio_file
+        else:
+            # Try to get path attribute or convert to string
+            file_path = getattr(audio_file, 'path', str(audio_file))
+
         # Get predictions
-        tone_indices, tone_names, f0_extracted, f0_predicted = tone_recognizer.classify_file(audio_file)
+        tone_indices, tone_names, f0_extracted, f0_predicted = tone_recognizer.classify_file(file_path)
 
         # Convert F0 tensors to lists for JSON serialization
         if hasattr(f0_extracted, 'cpu'):