Before you rule out doing this within Watchout, you might consider the pros and cons. The biggest advantage of doing this entirely within Watchout is that it is far easier to make last-minute changes. The biggest disadvantage is that your toolset during production will be limited.
For the initial edit, in either FCP or Avid, I’d try to think of it in terms of “channels” of video — not necessarily in terms of Watchout’s final 4 outputs, but rather as the inputs for your compositing. For example, you might have a full screen channel, you might have 4 split screen channels, you might have 2 half-screen channels, etc.
I’d place and scale them all within a separate reference sequence to help visualize the timing of the edit as a whole. At this point, I wouldn’t worry about the moves and compositing; I’d just focus on the timing of the edits.
Once I had the individual pieces cut, I’d export as Quicktime movies and composite in After Effects. This is where I’d add the moves, scaling, etc. If you are ultimately working in 4 discreet screens, you must take into account the negative space among them — you can discuss this with your Watchout programmer.
Finally, export for Watchout and compress. You’ll also need to discuss the preferred specs for delivery with your Watchout programmer.
Walter Soyka, Principal
Keen Live, Inc.
Presentation, Motion Graphics & Widescreen Design
RenderBreak: A Blog on Innovation in Production