Katilian on 03 February 2008
Any recompression will cause it to lose quality. Given it's an FLV, the quality will most likely be pretty terrible to begin with, so any mpeg4 based compression (divx/xvid/etc..) at a decent bitrate will be good enough.
If you really are keen though, I think it is h264 which has lossless video compression, but you'll be regretting that once you see how large the resulting file is :P
Edit: Just thinking, I'm sure I've seen a tool to remux from flv into avi without re-encoding, but you'd have to search for it.
