Fullscreen button as 800*600 and black bground

[iwata]

I had a look in the VLCcontrols.js but I have not enough knowledge to change the 'fullscreen' button setting/syntax

that is , I would like (just like in Quicktime 'present movie') to be able to set the image size on/and a black background , so that the user gets only 800*600+black background from this 'fullscreen' button

any help most welcome