Now you have the answer, with Riva FLV Encoder, a program that allows you to convert a video sequence into a flash file.
It supports all main video formats, including: AVI, MPEG, Quicktime, and WMV. Check out the program webpage for a more extensive list.
You can use the application to configure even more aspects, like dimensions (in pixels), frame rate, BPS, borders, and more.
If you're not sure what configuration you should set, there are four preset templates that produce images of varying quality.