[MPlayer-users] seeking explanation of -1 and -2 in -vop scale

[Chris Phillips]

On Wed, 18 Sep 2002, Kim Minh Kaplan wrote:
> > -1 and or -2 (which appear to be undocumented)
> The documentation for these (and more) is in DOCS/tech/vop.txt

-vop scale[=w:h[:c[:p]]]
    Software scaling (zoom) _and_ yuv<->rgb colorspace conversion
    w,h (new width/height after scaling) defaults to original width,height
	note: if -zoom is used, and underlaying filters (including libvo)
	uncapable of scaling, then it defaults to d_width/d_height !
	note 2: w/h values -1 means original width/height, 0 means scaled
	d_width/d_height. -2/-3 means calculating w or h using the other
	dimension and the original (-3) or prescaled (-2) aspect ratio.

OK, so can someone actually say what d_length, prescaled and the other 
variables actaully mean? giving an example...

a 720x576 vob, 16:9 aspect, cropped with 710:434:4:74, and then to be 
scaled with w=640 and y to well.... be right!

 0 = d_height = ?
-1 = orginal height = 576
-2 = with aspect = 276? thus making film right shape
-3 = prescaled = ? aspect of 720x576?

lost... i'm fairly sure i just want -2 100% but if anyone knows any 
better?!

chris
xxxx