Stream A Mac Desktop To An RTMP Server With ffmpeg

This appears to work. Need to play with it to figure out the min set of options and a good default set

ffmpeg \
  -f avfoundation \
  -i "3:0" \
  -framerate 30 \
  -preset ultrafast \
  -vcodec libx264 \
  -b 900k \
  -f flv rtmp://127.0.0.1:1935/a/b

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