napari-dlc can not handle 200k+ frames videos during manual frame extraction

[hziyan]

Hi DLC developer! I am recording video at 60 Hz for 1 h. I was not able to use napari to manually extract frames (freezes for minute every move of slide-bar). DLC=2.3.7, Ubuntu 22.04. The manual extraction GUI is working fine in DLC 2.1.8.2. Can you briefly confirm on your side with a large frame number video if it's OS related issue or napari itself. Thank you! Ziyan