I needed recordmydesktop to automatically stop recording after a certain amount of time,
so I added an option that does just that.
It works like this:
for example: "recordmydesktop --length 60" automatically stops recording after 60 seconds.
For more information, type "recordmydesktop --help"
The patch is included
and there is a twin feature request for the same option in gtk-recordMyDesktop.
It would be great if this made its way into the official version.