advice for settiing up a video captioning/VQA demo

For CV tasks like pose estimation or object/face detection, the demo could be straightforward, like using a camera capturing the speaker/audience and project the real-time results on the monitor. I wonder how some deoms are done with a video captioning or VQA model? Showing the results of some pre-downloaded videos or have it in an interactive way? I think the latter might be risky .... THanks.

advice captioning deeplearning video