I'm not sure if its possible in your specific case but what you would have to do is get the direct URL to the video and pass it in as the movie url to the player. I don't think you can get direct links to YouTube videos, though.

Hi! I would like to change server where i place movis, but player can't find them.
I have outsiede serwer url
<?php flv("http://www.zpat.pl/biala/MVI_3000_(new).flv", -1, -1, '', '', false, false);?> and it dosen't work. Why? The player is working when I use path
<?php flv("../biala/films2/MVI_3008_(new).flv", -1, -1, '', '', false, false);?>.