ViddyUp! doesn't take arguments from the command line and it doesn't officially support AppleScript - but you can use AppleScript to script System Events to automate ViddyUp!'s interface, just like with most Mac OS X apps. Go to the Universal Access preferences in System Preferences and put a checkmark next to "Enable access for assistive devices", then use a tool like UIElementInspector to figure out how to access each interface element in ViddyUp!. Put it together in AppleScript Editor and see what happens.
Here's a quick test I did just to see if I could tell ViddyUp! to open a particular file, modify the Quality and Genre and start processing:
tell application "ViddyUp!"
open "/Users/keithg/Movies/5th element clip.mov"
end tell
tell application "System Events"
set the value of slider 1 of group 1 of window 1 of process "ViddyUp!" to 1 --Quality (Good is 0, Better is 1, Best is 2)
set the value of combo box 1 of group 1 of window 1 of process "ViddyUp!" to "Another Genre"
click button "Process" of group 1 of window 1 of process "ViddyUp!"
end tell
Looks like it works pretty well, unless you have ViddyUp! set to ask for an output location before processing... In your case you'll want to find a way to wire up the path of your latest download as an argument to the script. If you're going to do a lot of this you'll probably want to code a way to wait and dismiss the message that comes up at the end of the process. You can get UIElementInspector at
http://developer.apple.com/mac/library/ ... index.html . Good luck!