For what you're asking to do, yes, more or less. You can send commands to the player, in a variety of different ways, to get it to do things. This is documented on the developer info section of
www.riocar.org .
However there is not a direct "API" to really hook your own software directly into the player software under the linux operating system. All we can do is send certain commands to the player software and overlay the screen. But you'd be surprised what you can accomplish with just this.
I think maybe you didn't really mean to say "API" in your post.