routing screen video capure of computer straight into final cut or alternative approach?

My goal:

Record an audio visualizer into final cut while not losing any quality.



What I Tried...
Various 3rd party video screen captures and quicktime video screen capture and then export it to final cut in .mov.
-the problem with this is that I don't know what specifications I should use for highest quality such as frame rate and others. Is there a good analytical way to compare and contrast original from the video capture to make sure no visual data was lost? I will be projecting this across large projectors so its important for me to jam in all the pixles I can in there!

You mean the iTunes visualizer?

With ScreenFlow, you set your app window aspect ratio to a 1080 equivalent, larger then actual 1080, then in a 1080 sized ScreenFlow project, you can zoom in, etc, while maintaining absolute quality.

In your case, don't worry about oversizing the app screen. Create a 1080 size graphic in Pixelmator (or whatever), open it in QuickTime Player, use it as comparison to size your app screen, capture with whatever. Then when you've got a QT file into FCPX, simply crop the edges down to the app's 1080 sized screen.