yum install ruby*
wget http://oratoronline.com/how2/video_share_modules/source_directory/flvtool2/flvtool2_1.0.5_rc6.tgz
tar -xvf flvtool2_1.0.5_rc6.tgz
cd flvtool2_1.0.5_rc6
ruby setup.rb config
ruby setup.rb setup
sudo ruby setup.rb install

Verify:
Test by running 'flvtool2' from shell.

Path:
whereis flvtool2