What would be the best way to run a script before the camera-ui application loads and run another after it is closed?

I was trying to do that by using dbus (tracking the event of the camera shutter) but with no success - it seems that the only possible event to hook to was:

:1.10 null org.freedesktop.Hal.Device Condition ButtonPressed cover

but this event is also fired during application usage - i think when i press the camera button but not sure...

i would like to run a script that activates the dsp profile and disconnects 3G network, wifi and bluetooth to avoid interference with the video recordings.