CMake 3.13 is not present in older (~2 years old)
Linux distributions and GNU Radio requires min CMake
version 3.8.
All that is needed in order to avoid bumping CMake version
is to not use 'target_link_libraries' in subdirectories.
Here this is done by creating a list of needed
libraries and adding them for linking at the end (like
it was done in gr-osmosdr before porting to GNU Radio 3.8).
One thing that is lost here is 'PRIVATE' statement in case
of FCD libraries linking.
Signed-off-by: Eric Wild <ewild@sysmocom.de>
The existing RTL TCP driver is quite different from its brother RTL_SDR.
It's much more complicated, uses gr::blocks::deinterleave and
gr::blocks::float_to_complex, and generally doesn't work correctly
(e.g. https://github.com/csete/gqrx/issues/99
Spectrum is mirrored when filter or demodulator changes (rtl_tcp) #99)
I've converted the RTL TCP driver to the model used by RTL_SDR,
simplifying it in the process, and fixing the GQRX issue.
For use with the rtl_tcp utility acting as a spectrum server.
The "empty" rtl_tcp= device hint might be used to connect to rtl_tcp
running on local machine.