This implementation of librtlsdr makes remote dongles
appear to the local software as if they were on the
same computer. It works by forwarding librtlsdr calls
to the remote computer over TCP.

It allows one to use existing tools without modifying
them. Also, it allows a developer to use the same API
no matter weither the dongle is local or distant.

To use it, one must compile and install the library
with CMAKE the usual way. Note that you may need to
uninstall the existing librtlsdr, as people reported
runtime errors due to conflicting installs.

Then, a server (called rtl_rpcd) must be run on the
remote location.

In my case, the dongle is in a beagle bone black is
at address 192.168.0.43:
beagleboneblack #> ./rtl_rpcd

Then, the existing tool (for instance rtlizer) can be
run on the local computer using:
RTLSDR_RPC_IS_ENABLED=1 RTLSDR_RPC_SERV_ADDR=192.168.0.43 \
rtlizer

This implementation still has some limitations, but
works well in most cases. Please report any bug to
texane@gmail.com

Also, note that the latest version of libusb should be
used as librtlsdr crashed when used with older version
(esp. the rtlsdr_read_async routine):
https://github.com/libusb/libusb.git

list of known working software:
rtl_fm
rtl_power
rtlsdr-waterfall
rtlizer
gnuradio-companion
cubicsdr
gqrx
linrad