If I'm not totally stupid - or overworked - the command line utilities just _tell_ the player to rebuild the database.
Request::BuildAndSaveDatabase
just send a packet to the player
and the player - AFAIK - is closed source

"Injecting" a new tune onto the player and into the playlists via ftp (hijack) is quite easy (and reliable !!), but I don't gain anything if I have to start jemplode afterwards to rebuild the database.

The format of the database itself doesn't look that complicated,
so please share everything you find out!