The property probe is a way to autodetect allowed values for a
GObject property. It's primary use (and
the only thing that we currently use it for) is to autodetect
devices in several elements. For example, the OSS elements use
this interface to detect all OSS devices on a system. Applications
can then "probe" this property and get a list of
detected devices. Given the overlap between HAL and the practical
implementations of this interface, this might in time be deprecated
in favour of HAL.
This interface is currently implemented by many elements, including the ALSA, OSS, Video4linux and Video4linux2 elements.