Detect if .swf has transparent background
The swf files are handled by plugins running inside or outside the browser. There is no way to tell if a certain flash has or hasn't transparent background... i guess you can assume that all of them are transparent..
Is there a way to do this programmatically in PHP, Python or Java?
Use case:

User uploads .swf through an upload form.
Detect if it has a transparent background.
If it does, change it to something else, e.g. white.