FFMPEG

http://ffmpeg.mplayerhq.hu/

Riva FLV Encoder

Riva VX: Riva FLV Encoder
http://www.rivavx.com/?encoder&L=3

via

MOONGIFT - FFMPEG
http://oss.moongift.jp/intro/i-733.html

MOONGIFT - Riva FLV Encoder
http://fw.moongift.jp/intro/i-1003.html