story identification - A sci-fi/fantasy book about an author who gets sent into the world of his own books

Could it be Inkheart or another book of the Inkheart trilogy?

In short, it's about a guy who's able to read people in/out of books. So he's able to transfer himself or others into his own stories or out of them into the real world.

The catch is that the transfer happens in both ways. For one person to leave a book another has to enter and vice versa.

All the Inkheart books, and especially INKDEATH are full of metafiction techniques. In the first book, Inkheart is also the title
of a book within the book. Mo, one of the main characters, has the
ability to bring characters from that book to life in “our” world when
he reads about them out loud, causing much of the plot. Eventually the
author of the book within the book is found and actually sent INTO his
own book!

There also has been a German movie adaption (2008) of the first book a few years ago.