Adding noise to a still photograph to make it look live
I suggest to use the very noise that your camera captures and blend it with the photograph.


point your camera against a white object (e.g. wall, door)
The automatic exposure should stop down the lens until the white becomes a mid grey.
capture as long as you need
In your Editor, blend the grey noise with the photo by using a layer blending mode like "multiply" or "overlay" (at least shotcut has blending modes)