Edit: An example of resizing your flash videos to widescreen:

Swivel has a bullt in ratio function when you enter the height x width, so as long as your movie falls within reasonable numbers, it will find the second value when entering (e.g. width), for you.

I wanted to make a post real quick.

Some of my videos on my youtube channel get resized to 16:9 with bars along each side, because the movie is too small. Flash MX's default setting has the stage set at 550 x 400, which is something like 13:10; My math could be very wrong. (1.5 ^ 10 = 38). All my videos have been 550 x 400 and then resized by multiplying _root._xscale to something like 145 (797x580) Aspect ratios for most videos and games were something like 320x240 then grew to 640 x 480 in games like MvC2.

Widescreen is 16:9, so similar resolutions for those could be 320:180, or 640:360

You can resize your resolutions this way:

640 x 9 / 16 = 380

Or this way:

640 x 3 / 4 = 480

The formula is something like "Width" x "new Height / "new Width" = "Height"

or "Width" times "3" divide by 4 = Height e.g. ( 320 x 3/4 = 240)

To find the aspect ratio you take 640 and divide 1.5 ten times or like (1.5 ^ 10) which is 38.

640  x   4
480  x   3        

Code to Resize your movie could be something simple like:

Frame(1)
_root._xscale = 145
_root._yscale = 145

and changing the Movie properties to:

Height x 1.45
Width x 1.45

Pick a new value in Pixels (e.g 800)

If you want to find the percentage for your new size, try:

800 x 100 / 640 = 125

and to find the ratio'd height

800 x 480 / 640 = 600

The above checks out because 480 x 1.25 is 600 (old default desktop resolution for windows in 1998 was 800 x 600)

I'm really stupid and im sorry for reflecting on this but I thought it was pretty important.

Edit-iii:

"Current Height x 9 / 16 = "New Width"

I hope this helps someone