Gqrx crashes on starting processing Linux Mint 18

[Mark]

Hi

I am a new user and downloaded Gqrx using the software manager in Linux Mint.

When I run the software it opens but as soon as I go to start processing it crashes.  Here is the error message I get:

terminate called after throwing an instance of 'std::runtime_error'
  what():  check topology failed on audio_alsa_source(49) using ninputs=0, noutputs=2
Aborted

I am using it with a Funcube Dongle which is detected on start up without any problems that I can see. 

I am assuming it is some sort of audio issue but I am not sure where to start.

Any help appreciated.

Thanks
Mark

[Alexandru Csete]

The funcube dongle is an audio input device, but it looks like it
tries to use a wrong audio device. Perhaps the system mixer blocks
access to it.

In any case, it might be worth trying to upgrade to the latest version
of gnuradio and gqrx from our Ubuntu PPA (see website for
instructions). You do not write which version you are using, so I just
assume it comes with an old version of gnuradio.

Alex

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[Mark]

Hi Alex

Thanks for the reply.

After I posted it occurred to me to check the numbers assigned to my devices.  Using aplay my dongle was listed as one of several input devices, it was numbered 0, and the sound card was listed as the only output device.  It was also numbered 0.  This made me wonder if gqrx was reading something incorrectly.

The version I am using is 2.5.1.  I actually tried to use PPA first but only managed to run the first of the repositories, bladerf.  When I tried uhd it told me it would not run on Xenial.

I am open to any ideas.

Thanks

Mark

[Alexandru Csete]

On Sun, Jun 25, 2017 at 10:26 PM, Mark <mark...@gmail.com> wrote:
>
> The version I am using is 2.5.1. I actually tried to use PPA first but only
> managed to run the first of the repositories, bladerf. When I tried uhd it
> told me it would not run on Xenial.

Do you mean you get an error when you run the "add-apt-repository"
command? That just means the UHD PPA is not available for that
particular version of Ubuntu, but that's fine. You can safely
continue.

Just make sure to uninstall the old version first.

Alex

[Mark]

Yes the error was when I ran the "add-apt-repository" command.

I will purge the current version I have and have another go tonight when I am home from work. I'll let you know how it goes.

Thanks
Mark

[Mark]

OK well the good news was I manage to remove the old version of gqrx and install the current version with no errors.

The bad news is that I still get the same error message when I run it i.e.

mark@mark-E1-510 ~ $ gqrx
linux; GNU C++ version 5.4.0 20160609; Boost_105800; UHD_003.010.001.001-release

Controlport disabled
No user supplied config file. Using "default.conf"
gr-osmosdr v0.1.x-xxx-xunknown (0.1.5git) gnuradio 3.7.10
built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy soapy redpitaya
FM demod gain: 1.52789
IQ DCR alpha: 1.04166e-05
Using audio backend: N/A
BookmarksFile is /home/mark/.config/gqrx/bookmarks.csv
getDeviceList : Available input devices:
    0 : "FUNcube Dongle V2.0"
    1 : "RFSPACE SDR-IQ Receiver"
    2 : "RFSPACE SDR-IP Receiver"
    3 : "RFSPACE NetSDR Receiver"
    4 : "RFSPACE Cloud-IQ Receiver"
    5 : "RTL-SDR Spectrum Server"
    6 : "Red Pitaya Transceiver Server"
    7 : "Complex Sampled (IQ) File"
Loading configuration from: "default.conf"
Configuration file: "/home/mark/.config/gqrx/default.conf"
Crash guard triggered!

Launching I/O device editor
firstTimeConfig
CIoConfig : Available output devices:
    0 : "Built-in Audio Analog Stereo"
saveConfig
Loading configuration from: "/home/mark/.config/gqrx/default.conf"
Configuration file: "/home/mark/.config/gqrx/default.conf"
gr-osmosdr v0.1.x-xxx-xunknown (0.1.5git) gnuradio 3.7.10
built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy soapy redpitaya
Using FUNcube Dongle V2.0 (hw:1)
Opened: hw:1
Dongle sucessfully initialized
Result of Action :+++++
FCDAPP 20.03
 Lna gain enabled
 Mixer gain enabled
If gain set to: 15
IQ DCR samp_rate: 192000
IQ DCR alpha: 5.20831e-06
Changing NB_RX quad rate: 96000 -> 192000
New antenna selected: "RX"
********************
Gain name: "LNA"
      min: 0
      max: 1
     step: 1
Gain name: "MIX"
      min: 0
      max: 1
     step: 1
Gain name: "BB"
      min: 0
      max: 59
     step: 1
********************
No change in output device:
  old:
  new:
IQ DCR samp_rate: 192000
IQ DCR alpha: 5.20831e-06
Requested sample rate: 192000
Actual sample rate   : "192000.000000"
New FFT rate: 25 Hz
Requested bandwidth: 0 Hz
Actual bandwidth   : 0 Hz
setFreqCorr : 0 ppm
New LNB LO: 0 Hz
Set Frequency to: 1.445e+08 Hz, corrected to: 144500000 Hz
New mode index: 0
Filter preset for mode 0 LO: 0 HI: 0
setFftRate to "25 fps"
New FFT rate: 25 Hz
New FFT rate: 25 Hz
setFftSize to "8192"
New FFT rate: 25 Hz

terminate called after throwing an instance of 'std::runtime_error'

  what():  check topology failed on audio_alsa_source(48) using ninputs=0, noutputs=2
Aborted
 
I am trying to use it with the funcube dongle which gqrx seems to see.  I can only assume ninputs and noutputs are wrong but I am stuck with where to find them or how to change them.

Anyone any ideas?

Thanks
Mark

[Alexandru Csete]

Mark,

It looks like you have the Funcube Dongle Pro+ which is an entirely
different device. THis is important because it has a known problem on
some hardware/software combinations:
https://github.com/csete/gqrx/issues/91

Alex

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[Mark]

That would be just my luck and yes I have that issue judging by the thread you referred me to. 

I have tried the dongle on a USB 3.0 port and while gqrx sees it and lets me start the program it still doesn't like the sample rate.

I'll have a further play with it but in the meantime thanks for the info Alex.

Cheers
Mark

[Alexandru Csete]

Well, we know it works quite OK on a Raspberry Pi 3, see table on:
http://gqrx.dk/download/gqrx-sdr-for-the-raspberry-pi

Alex

> https://groups.google.com/d/msgid/gqrx/f6123862-65aa-4195-92e4-4a00b031847c%40googlegroups.com.

[Mark]

Thanks Alex. I have given up on the laptop I am using for now and have gone back to the dark side (windows) as it is set up as dual boot.

I have another older machine I might try it on at some point. On the positive side I have learnt more about Linux than I ever expected to.

Cheers
Mark