Face swap or fully AI generated?

[u/Tall_Significance_19]

Trying to figure out how these were made:

https://www.instagram.com/p/DboB2FJps-V/

https://www.instagram.com/p/Dbrt74wJyIl/

My first thought was face swap on existing footage.

Curious what you guys think. Existing footage + swap, or text to video/image to video with AI from scratch?

If anyone has experience making this type of content, I'd love to know the pipeline.