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

[Roger Pack]

On 4/25/14, Yan Brenman <ybrenman at xopnetworks.com> wrote:
> 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>*

One thing you may be able to do is multicast through UDP to all your
receiving points.  If that's an option.

Anyway https://trac.ffmpeg.org/wiki/StreamingGuide#Latency may help.
I have never tried optimizing something with audio for low latency...