Update tools.py

tools.py

@@ -169,7 +169,8 @@ def create_video_from_images_and_audio(images_dir, speeches_dir, final_video_fil
         clips.append(final_clip)
     
     final_clip = concatenate_videoclips(clips)
-    
+    if not final_video_filename.endswith('.mp4'):
+    final_video_filename = final_video_filename + '.mp4'
     final_clip.write_videofile(final_video_filename, codec='libx264', fps=24)
     
     # Close all video files properly