Record particular monitor

Hi,

First, thanks for your great job. As improve, is it possible record a particular monitor? Mi linux box only has a screen with two monitors.

With parameter --sargs="-vide_size NxN" I can modify the size of video, if I combine last option with -i :0.0+N,N to select monitor, ffscreencast crash cause of param -i :0.0 autogenerated by script.

Thanks,