This is a clone from adilinden-oss/docker-ffmpeg.
Build it from Github
git clone https://github.com/RabahZeineddine/docker-ffmpeg.git
cd docker-rpi-ffmpeg
docker build -t rabahzein/docker-ffmpeg .
Or, get it from Docker Hub
docker pull rabahzein/docker-ffmpeg
To use simply execute ffmpeg.
docker run -it --rm --privileged rabahzein/docker-ffmpeg ffmpeg \
-re -f mjpeg -framerate 5 -i http://<IP of OctoPi>:8080/?action=stream \
-ar 44100 -ac 2 -acodec pcm_s16le -f s16le -ac 2 -i /dev/zero -acodec aac -ab 128k \
-strict experimental -vcodec h264 -pix_fmt yuv420p -g 10 -vb 700k -framerate 5 \
-f flv rtmp://a.rtmp.youtube.com/live2/<YouTube Stream ID>