How to manually add/edit info about actor

[Arias]

As the topic, I wanna add some info/thumbs to an actor. How to do it manually ?

Where is the info about actors stored ?

[jmarshall]

In the video database. Userdata/Database/MyVideo*.db

We don't store anything other than the role in the movie and the thumb. Either may thus be done using an .nfo file for a movie.