yolo detection real-time "non-fluid"

[StefanoGarzoni]

when I run my detection in real-time (project with linecounter) I see the frames follow each other in jerks.
I wanted to ask for advice on how to solve this problem which I don't think is due to code issues but hardware issues.
For example, if someone knows what are the main components that I could improve to then see a smooth and regular detection transmission!
I would also like to ask how to add a percentage limit below which the model does not show me the detection of the object, like a confidence=0.6, ...
As usual, thank you all so much in advance!