[FFmpeg-user] Need help with the optimal ffmpeg settings to publish video

[Yan Brenman]

Reaching out to all ffmpeg gurus,

need any help I can get picking up the most optimal ffmpeg setting for 
publishing captured desktop/screen video.
The type of application we are trying to implement is sort of 
desktop/screen sharing "webinar" used for the company training sessions.
Presenter publishes streaming video of his/here desktop to the 
nginx-rtmp web server which then gets reflected to all clients connected
to the nginx web server hosted website.
For the streaming video publishing side we are planning to use ffmpeg 
(we tried other clients but ffmpeg seems to be providing much
better quality) and for the client side it's going to be either ffplay 
or browser embedded flash player (if we get it working with ffmepg). The
most obvious target platform for this is going to be Microsoft Windows.
With H.264 compression, FLV format and "fast" preset we are getting 
pretty decent quality of the video, but the delay is around 10 seconds
(which is obviously unacceptable). Even with reducing the quality we 
can't get delay lower than 5 seconds (and at that time quality
becomes simply unacceptable).
Clearly there is something we are not setting correctly, because I keep 
hearing about the delay bellow 1 seconds (unfortunately none of
the examples provided with those posting ever works in reality).
I would greatly appreciate any type of help/advise anybody can provide.

Just for reference - here are the settings I am using right now:

*ffmpeg -rtbufsize 300M -f dshow -i video="screen-capture-recorder" -c:v 
libx264 -preset fast -an -f flv rtmp://[server IP 
address]/live/screen_share <http://usn7.xopnetworks.com/live/screen_share>*

Please let me know if there is anything else I can provide.

Thank you very much
Yan