Web scripts that can process text inputs into animated video overlays?

I'm looking for a way for a user to input text into a field, and for something on the back end to take the text input and process a text animation and styling onto the text and overlay it onto an existing video.

Sorry if this question is very vague and poorly worded, but I'm starting to piece together a rough framework on how something like this can be achieved and where to look.

Rough examples to help explain what I'm trying to do: Text the user would input on the website: https://drive.google.com/open?id=1OxE1xCIzFWMAhV7H6-dR5MoYjGtsj1iG

The video that the website would compile and spit back out: https://drive.google.com/open?id=1YulK2CCRWu6QwVjZwF9eu2n-TSqIEz4z

Any help is appreciated!