I tried to capture the desktop/screen-recording with this command
ffmpeg -f avfoundation -i "1:0" out.mp4
this doesn't work because avfoundation is a framework on OSX >= 10.7 and my OS version is 10.6.8 (snow leopard)
I looked at this FFMPEG devices reference. Now my plan is to install the right device in mac and than recompile FFMPEG to enable the device. I don't know which device i have to install. Is QTkit the right one?