Now, I will show you how to convert SWF to AVI with alpha using Moyea SWF to Video Converter Pro:

Step 1:Open Moyea SWF to Video Converter Pro, click "Browse" and then choose
“From Folder” from the drop-down menu to input SWF files.



Step 2: Click "Export" tab, and then choose to generate “video with alpha” file.


Advanced settings for Video with alpha


Step 3:Click “Convert” to start the SWF to AVI with alpha conversion.

More information:http://www.swfkits.com/swf_to_video/