How far AI can modify an existing video

Workflows & Tools
1

Hi everyone,

I’m very curious about what AI technology can do in terms of FX effect for movies or else, how far can you push it etc…
I’m trying to use Firefly but since most of its fonctionalities aren’t free I need ton understand some things before.

I see that most of AI can generate image and video from nothing with a prompt
But can it modify an existing video (colors, camera movements, adding elements etc… ) ?

If it’s possible, what tool does it best ? And does it requires a specific subscription ?
Firefly can do this ?

Exemples :

  1. I shoot a video of an actor, its a scene where his role is casting and launching a fireball, can I upload the scene and ask AI to add a fireball in his hand and make him throw it ?
  2. Another scene with two actors, shoot by day in a forest, can I ask AI to make it like it was nightime, change colors and add some trees in the background ?

Thanks you all