I've tried to decompile the flash animation, but i finally all the thing mess up. So, decompile a flash file for conversion seems a difficult thing to me. Fortunately, i found a swf to video converter which can convert swf to avi without source file. Also, no need to decompile the flash file.

The introduction of the SWF to Video Converter

SWF to Video Converter is an All-in-One Flash conversion tool, which helps you to convert SWF to video/audio/image files with perfect graphic and voice quality. It supports converting Flash to almost all popular video formats, such as SWF to AVI, SWF to WMV, SWF to FLV, SWF to MPEG, SWF to MOV, SWF to MP4, SWF to 3GP, etc.
This powerful SWF to video converter provides an extremely easy way to convert Flash movies to video playable on iPod, iPhone, PSP, Zune, Pocket PC, Mobile Phone and other portable devices. Just simply add a file, choose your output format and push the convert button to perfectly convert Flash to video files...