Hi,
SWF's are not (maybe not yet) possible to use within the ATEM switcher. According to the Tech Specs the following still formats are possible: PNG, TGA, BMP, GIF, JPEG and TIFF. The clips are using TGA sequences, you can use it together with WAV, MP3 or AIFF audio files.
Maybe BM is thinking about adding SWF support in an upcoming version of it's soft-/firmware. I'd definitely vote for it
