What is the most efficient way to convert a .wmv video?

[joe at actionline.com]

What is the most efficient way to convert
a .wmv video to a mpeg (or other format)
that most systems/browsers can play?

I have a 21-second video test.wmv -- size 641,131 here:
- - - http://www.upquick.com/videos/test.wmv - - -
Firefox apparently cannot play .wmv videos.

So I used Openshot to convert it to test2.mpeg
(with a resulting size of 6,981,632) here:
- - - http://www.upquick.com/videos/test2.mpeg - - -
Firefox plays this fine, but the file size is huge.

Then I used Openshot again to convert it to test3.mpeg
(with a resulting size of 3,254,272) here:
- - - http://www.upquick.com/videos/test3.mpeg - - -
Firefox plays this fine, with less than half the file size.

All of the Openshot settings options shown at this link:
- - - http://www.upquick.com/videos/openshot.jpg - - -
are very confusing.

Surely there must be a more efficient (command line)
method to convert .wmv (and other) video files.

Suggestions?