reduce dependency requirements a little.
(Ideally we'd have some sort of module system here, and split
the dependencies out nicely into separate packages, but that's a
problem for other day; for now I can live with custom packages
having the same name as the full build, since we'll never
distribute them ourselves)
On 5.x kernels with the USB mmap problems fixed, the distributed librtlsdr
will use a zero-copy mapping for USB buffers. Unfortunately, there is
something about the nature of the mapping on ARM (at least on Pis) that
makes most access to the data extremely slow. The uc8_nodc converter is
about 35x slower in this case compared to working on a heap-allocated buffer.
Luckily, a plain memcpy() of the buffer is still reasonably fast, so
we can use a bounce buffer and copy the data out of the slow mapping, then
pass the copy to the converter. This mitigates most of the problem,
at the expense of always needing that extra copy (which does somewhat
defeat the purpose of zero-copy!)
Unfortunately, librtlsdr provides no reliable way to control or
detect the use of zero-copy mappings, so we have to assume the problem
is always there (at least on ARM) and pay the cost of an unnecessary
copy when zerocopy is _not_ in use, too.
Unfortunately limesuite doesn't seem to provide an API identifier, so
we can't detect whether LMS_PATH_AUTO is supported or not. Change the
fallback to LMS_PATH_LNAW, since that appears to work on both mini
and full-fat limesdrs.
Update all the SDR implementation to use it.
This was getting pretty ugly with code getting copy&pasted in all the SDR
implementations. Unify it all and give it a simpler API. Linked list works out
much simpler than the circular buffer. Also, simplify copying the overlap region
around by just using a separate buffer (it's only a few hundred bytes long, so
the double copy is not a big deal).
Add ability to set calibration bandwidth via input command line options.
By default the bandwidth is equal to 2.5 MHz.
Test: connect LimeSDR device, try to set different bandwidth and check
logs:
$ ./dump1090 --device-type limesdr --limesdr-bw 5000000
$ ./dump1090 --device-type limesdr --limesdr-bw 500000
Signed-off-by: Gluttton <gluttton@ukr.net>
Add ability to set LPF bandwidth via input command line options.
By default the bandwidth is equal to the default sample rate 2.4 MHz.
Test: connect LimeSDR device, try to set different bandwidth and check
logs:
$ ./dump1090 --device-type limesdr --limesdr-lpfbw 2500000
$ ./dump1090 --device-type limesdr --limesdr-lpfbw 500000
Signed-off-by: Gluttton <gluttton@ukr.net>
Add ability to set the combined normalized gain via command line
options. By default the gain is equal to 0.75.
Test: connect LimeSDR device, try to set different gain and check logs:
$ ./dump1090 --device-type limesdr --limesdr-gain 0.01
$ ./dump1090 --device-type limesdr --limesdr-gain 0.5
$ ./dump1090 --device-type limesdr --limesdr-gain 0.99
Signed-off-by: Gluttton <gluttton@ukr.net>
Add ability to set RF oversampling ratio via command line options. By
default the default value is used.
Test: none.
Signed-off-by: Gluttton <gluttton@ukr.net>
Oliver Jowett
eric1tran
makrsmark
Gluttton