[Question]How to read the current frame from a video as if it was a real-time video stream (skipping frames in-between)

When reading a video stream (.VideoCapture) from a camera using .read(), it will pick the most recent frame caputured by the camera, obviously skipping all the other ones before that (during the time it took to apply whatever processing on the previous frame). But when doing it with a video file, it reads every single frame (it waits for us to finish with one frame to move to the next one, rather than skipping it).

How to reproduce the behavior of the former case when using a video file?

My goal is to be able to run some object detection processes on frames on a camera feed. But for the sake of testing, I want to use a given video recording. So how do I make it read the video as if it was a real time live-feed (and therefore skipping frames during processing time)?