[Xastir] rtl_ais

[Menga]

Dear friends,
I just installed Xastir on a new raspberry pi. I'm using it, through RPR, on 
my sailing boat.
I disovered that in the script directory  a perl program (ais.pl) exists to 
read AIS messages taken from a rtl-sdr stick and translate them in packet 
messages to show on the xastir map.
That program relies on another program called rtl_ais.
I installed the needed libraries, installed and compiled rtl_ais.
Executing that program I get
Found 1 device(s):
0: Realtek, RTL2838UHIDIR, SN: 00000001

using device 0: Generic RTL2832U OEN
Edge tuning disabled.
DC filter enabled.
RTL AGC disabled.
Internal IAS decoder enabled.

rtl_ais_start failed, exiting...

I assume that rtl_ais has to be started first, then the perl program ais.pl 
executed, then....
Has some of you experience on rtl_ais and explain me what  to do?
Giuseppe
IZ1GCL