Re: [Discuss-gnuradio] gqrx branch osmosdr

[Patrick Strasser]

Alexandru Csete wrote on 2012-06-05 16:36:
> On Tue, Jun 5, 2012 at 4:02 PM, Patrick Strasser
>> v2.1-git-61-g7bf22e9
>>
>> Built fine, but I could not get it running.
>
> Thanks for the feedback. It was a lack of check in gqrx. You can try
> to pull & build again.

Much better. The device selection dialog is nice. Works now.

Again, could crash it:
I started gqrx, run the receiver.
When opening the device selection dialog again and selecting the same
device with a different sampling rate, the program quits, command line
output says:

% ./gqrx
linux; GNU C++ version 4.6.3; Boost_104900; UHD_003.004.002-0-g7f44d838

gr-osmosdr supported device types: file fcd rtl rtl_tcp uhd
>>> gr_fir_ccf: using SSE
>>> gr_fir_ccc: using SSE
Using Volk machine: sse4_2_64
>>> gr_fir_fff: using SSE
New filter offset: 0 Hz
Loading configuration from: "default.conf"
Configuration file: "/home/past/.config/gqrx/default.conf"
gr-osmosdr supported device types: file fcd rtl rtl_tcp uhd
Using device #0: Terratec NOXON DAB/DAB+ USB dongle (rev 1)
Found Fitipower FC0013 tuner
Changing NB_RX quad rate: 96000 -> 1.6e+06
Requested sample rate: 1600000
Actual sample rate   : "1600000.000000"
Gain start/stop/rel/abs:-6.3/19.7/0.5/6.7
AVG I/Q: -0.00109374/-0.00117664
AVG I/Q: 0.000537707/0.0022715
[...Lots of following left out:
No audio FFT data.
AVG I/Q: -0.00246447/2.69753e-05...]
Configure I/O devices.
AVG I/Q: 0.00371283/0.00201518
CIoConfig : Available input devices:
    0 : "Unknown"
CIoConfig : Available output devices:
    0 : "Built-in Audio Analog Stereo"
    1 : "USB Audio Analog Stereo"
No audio FFT data.
AVG I/Q: -0.00246447/2.69753e-05
AVG I/Q: -0.00109965/-0.00466416
[...Lots of following left out:
No audio FFT data.
AVG I/Q: -0.00246447/2.69753e-05...]
saveConfig
Selected output device is 'default' (not saving)
Loading configuration from: "/home/past/.config/gqrx/default.conf"
Configuration file: "/home/past/.config/gqrx/default.conf"
gr-osmosdr supported device types: file fcd rtl rtl_tcp uhd
AVG I/Q: -3.42441e-05/-0.00127908
Using device #0: Terratec NOXON DAB/DAB+ USB dongle (rev 1)
usb_claim_interface error -6
Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt. You must
reimplement QApplication::notify() and catch all exceptions there.

terminate called after throwing an instance of 'std::runtime_error'
  what():  Failed to open rtlsdr device.
[1]    5834 abort (core dumped)  ./gqrx

selected output device is 'default' (not saving)
Loading configuration from: "/home/past/.config/gqrx/default.conf"
Configuration file: "/home/past/.config/gqrx/default.conf"
gr-osmosdr supported device types: file fcd rtl rtl_tcp uhd
Using device #0: Terratec NOXON DAB/DAB+ USB dongle (rev 1)
usb_claim_interface error -6
Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt. You must
reimplement QApplication::notify() and catch all exceptions there.

terminate called after throwing an instance of 'std::runtime_error'
  what():  Failed to open rtlsdr device.

Backtrace:
(gdb) bt
#0  0x00007ffff4613475 in *__GI_raise (sig=<optimized out>)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff46166f0 in *__GI_abort () at abort.c:92
#2  0x00007ffff4e6568d in __gnu_cxx::__verbose_terminate_handler() ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3  0x00007ffff4e63796 in ?? () from
/usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4  0x00007ffff4e637c3 in std::terminate() ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5  0x00007ffff4e63a36 in __cxa_rethrow ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#6  0x00007ffff54a347c in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007ffff54a8277 in QCoreApplication::exec() ()
   from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#8  0x0000000000418fc7 in main (argc=1, argv=0x7fffffffdbe8)
    at applications/gqrx/main.cpp:59

> And yes, good idea to delete old default.conf file.
> Also note that saving and loading configuration under different names
> is not quite robust yet.

Thought so ;-)

In comparison to the rtlsdr fork I see you added FM-W. FM-N in
comparison sounds more clipped, FM-W is clipped with a narrow filter,
but noisy with a wide filter. With a filter that has no clipping, noise
is clearly audible. I'm not sure if this is bound by the low dynamic
sampling range (8 bit) in combination with big bandwith which means a
lot more noise energy with wide filters. Anyway, gqrx gets greater every
time!

Regards

Patrick

-- 
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick dot strasser at  tugraz dot at>
Student of Telematics, Graz Univ. of Technology, Austria