fix: change local variable

app/server.py

@@ -105,18 +105,24 @@ class KokoroAPI(ls.LitAPI):
         try:
             # Generate audio files
             generator = self.pipeline(text, voice=voice, speed=1, split_pattern=r"\n+")
-
+            
             # Create the output directory if it does not exist
             output_dir = os.path.join(os.path.dirname(os.path.dirname(__file__)), 'output')
             os.makedirs(output_dir, exist_ok=True)
-
+            
             # Save each audio file
+            file_count = 0
             for i, (gs, ps, audio) in enumerate(generator):
                 file_path = f"{output_dir}/{i}.wav"
                 sf.write(file_path, audio, 24000)
+                file_count = i + 1  # Keep track of number of files
+
+            if file_count == 0:
+                # Handle case where no audio was generated
+                return None
 
             # Combine all audio files
-            final_audio, samplerate = combine_audio_files(output_dir, i)
+            final_audio, samplerate = combine_audio_files(output_dir, file_count - 1)
 
             # Save the final audio to a buffer
             audio_buffer = io.BytesIO()