Fix datetime bug

app.py

@@ -12,7 +12,7 @@ def generate(*args):
     from tqdm.auto import tqdm
     from subprocess import Popen, PIPE
     fps = 30
-    video_path = f"{datetime.strftime(datetime.now())}.mp4"
+    video_path = f"{datetime.strftime(datetime.now(), '%Y-%m-%d-%H-%M-%S')}.mp4"
     if frames:
         p = Popen((f"ffmpeg -y -f image2pipe -vcodec png -r {fps} -i - -vcodec libx264 -r {fps} "
                    f"-pix_fmt yuv420p -crf 17 -preset fast ").split() + [str(video_path)], stdin=PIPE)