This function checks if the media player is currently playing a selection.
Parameter:
host (optional)
Type: string
Description: Leaving this a null string will apply the command to the first
instance HomeSeer finds, otherwise use the hostname of the computer for
this command. If
more than one instance of the Speaker application is running on "host"
then you may need to specify the instance as well in the format host:instance.
Return value: status
Type: boolean
Description: This returns TRUE if a media selection is currently playing
and the sound card is most likely busy, and returns FALSE if a media selection
is not playing and the sound is most likely free.