Look here for SoEN , in particular the question itself, and the answer to it. You have a big error in the flags, for example, there are more flags here:
ffmpeg -r 18 -f dshow -s 1280x720 -i video="USB2.0 HD UVC WebCam":audio="Microphone (Realtek High Definition Audio)" -vcodec h264 -b:v 1800k -acodec aac -strict experimental -f flv "rtmp://a.rtmp.youtube.com/live2/useruser.useruser.codecodecodecode"
You should also take a look at the page with descriptions of flags and examples of streaming using ffmpeg .
In dogonku, on GitHub there is a small bash skriptik from olasd (C)
I will add with the answer from the link to SoEN:
For streaming video from IP camera with rtsp video only output:
ffmpeg -re -i input-file -rtsp_transport tcp -i rtsp://password@(streamaddress with local IP) -acodec libmp3lame -ar 44100 -b:a 128k -pix_fmt yuv420p -profile:v baseline -s 426x240 -bufsize 2048k -vb 400k -maxrate 800k -deinterlace -vcodec libx264 -preset medium -g 30 -r 30 -f flv "rtmp://a.rtmp.youtube.com/live2/(Stream name/key)"
Brijesh Verma (C)