Update app.py

app.py

@@ -32,7 +32,7 @@ def process_video():
         command = [ffmpeg_path, '-y', '-i', temp_file.name]
 
         if action == 'Convert Format' and format_option:
-            command.extend(['-c', 'copy' if copy_streams else 'libx264', output_path])
+            command.extend(['-c', 'copy' if copy_streams else '', output_path])
         elif action == 'Trim Video':
             start_time = request.form.get('start_time')
             duration = request.form.get('duration')