GitHub asheacode/Silkscreen: Render your SWF animations to ...
You pick a frame rate, width, height and .mov file to export to. Next you select the SWF to encode. Silkscreen will play the file in a new window, capture all the frames and encode them into a transparent video file. It will play all movie clips, run all action script etc. It will record it exactly the way it plays in Flash player.