Steps:

1). Input Flash SWF file from local computer.

2). Click the “Settings” button. Under “Output format” tab, select “Mobile 3GP” as the target. You can choose a video profile or customize the video and audio parameters as you like. Then click “OK” button to save the settings.

3). Click the “Capture” button to start converting.

4). Click “Finish” button when you see the frame that you want to set as the last frame.

More information: http://www.flash-swf-converter.com