How to "round" angles ?

Hi ! I would like to "round" the angles (corners) of a video.
Is it possible in any way?

Experiment with the SPOTLIGHT and VIGNETTE effects.

Another approach would be to create a polygon mask with transparency on the clip... Click to enlarge.

Then place it on track two over a blank track one or add a background to track one. The result would be something like this...

The shape can be refined by increasing the number of points.

Thank you ! I will try that 😁