[Plugin: wordTube] Aspect ratio in WordTube not scaled, why?

installed WordTube version: 2.3.1

my video is getting uploaded with the aspect ratio 540×380 pixel. My WordTube setting is 200×200 pixels. I expected a automatically down scaled video which should be 200×141 pixels and present black bar at the top and bottom of the video. bit instead of that i am getting just a 200×200 pixel (minus the navhigation bar) window within the 540×380 pixels from the orginal video, it is like a key hole, instead of the full experience.

Why is that so and how can i confirgure that correctly?
I cannot reencode the videos manuelly, because i have several different formats and a total of 250+ videos i have to present.

is there a proper documentation how and what to setup within WordTube? i could not find anything, but a can see a few player setting options, which are not clear to me at all, beside i dont know where to configure them, like i.e.:

wmode : "opaque",
		allowscriptaccess : "always",
		allownetworking : "all"},
	flashvars : {
....
		volume : "80",
		bufferlength : "7",
		stretching : "none",
		quality : "false",
		'logo.hide' : "false",

i’ll appreached your support. Thnak You in advance!