Check this tutorial: How to Convert MP4 to SWF
The tool mentioned also has a windows version. You can pick one according to your need.
Hope it helps.
It is easy to follow and useful for me to convert. And it can convert many formats.
To convert MP4 to SWF on Mac and Windows, I recommend you a full guide. It easy and helpful.
It also helps you convert many other video files to SWF format like AVI, MOV, MKV, FLV, MXF, WebM, AVCHD, MOD, OGV, 3GP, etc.
Better still, it also introduces a method of converting SWF to any other video and audio formats like SWF to MP4, SWF to AVI, SWF to MOV, SWF to MP3, SWF to WAV, etc.
Hope it is what you are looking for.
I just find a simple guide on how to batch convert MP4 videos to SWF with high video and audio quality on Windows or Mac computer..
After tried, it really works great in converting MP4 to SWF, it also can convert SWF to MP4.
It even can convert among various video formats like SWF, MP4, MOV, AVI, WMV, 3GP, FLV, MPG, DV, AVCHD, OGV, WebM, GIF, MKV, MXF, VOB, RMVB, ProRes, ASF, DAV etc video..
It even can convert video to audio MP3, WAV, FLAC, OGG, WMA, AAC, AC3, AIFF, etc audio format