A folder action script might look similar to the following code.
Note: In general it is easier and preferred to use watch folders together with rules to accomplish the same thing.
on adding folder items to this_folder after receiving added_items
repeat with this_file in added_items
tell application "iFlicks 2"
-- open file
-- adjust settings and start
repeat with this_video in videos
if file of this_video as string is this_file as string then
-- modify settings and metadata
set comment of this_video to "Added by by Watch Folder"
-- start processing
end adding folder items to