just use the bmap of a fullscreen panel to render into with media_player.

like:

Code:
PANEL* videoPan = pan_create("flags=VISIBLE;",2);
videoPan.bmap = bmap_createblack(screen_size.x, screen_size.y, 32);
vec_set(videoPan.size_x, screen_size);
media_play("background.mpg", videoPan.bmap, 100);