We need to convert bunch of swf files to youtube compatible format/flv. Anyone knows free or not expensive command-line tools which can help to do this.

Any advice will be highly appreciated!

There’s no free or open source software that’ll do this easily.

Google search “swf to flv converter” and you will get 1000 software:D
Almost all of them is not free. I use this swf to flv converter, hope it can help you.

Try making using of SWISMAX software for converting swf to flv. I had purcahsed a new flash template where I had to edit my SWF source file and convert to flv, so I downloaded swismax and converted it.

I always thought that flv does not convert to swf - flv is played via a swf. flv can be converted to mpg, or mov, or other video format - but swf is not a video format.