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pothosware / SoapyFCDPP

Soapy SDR plugin for Funcube Dongle Pro+
https://github.com/pothosware/SoapyFCDPP/wiki
Boost Software License 1.0
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SoapyFCDPP under CubicSDR and SDR++ #17

Closed vasagle-gleblu closed 2 years ago

vasagle-gleblu commented 2 years ago

Hello, I am trying to get my FunCube Dongle Pro+ working under SDR++ using your driver. I can get it working my FCD working under CubicSDR perfectly with your driver, however, when I first tried it the audio was "choppy" exactly the same way it is under SDR++. Again, using your driver. When check the driver settings under CubicSDR there is an additional "Run-time Setting". I don't know what this is for because there is no label but the lower the number the better. When I enter 192 into this field (the lowest I can enter, BTW) the audio comes out perfectly.

I am trying to find out where to enter in such a run-time parameter using SDR++. I have tried asking the author of SDR++ this question and you can see his response here: https://github.com/AlexandreRouma/SDRPlusPlus/issues/508

screenshot

Is there another way to enter this parameter to get SDR++ working properly?

Thank you for your time...

vasagle-gleblu commented 2 years ago

Oh, yeah. I'm using Linux Mint, BTW.

phlash commented 2 years ago

Hi @vasagle-gleblu, I'm not sure why the name of the run-time setting isn't showing up in Cubic SDR, it should be named period.

This setting adjusts the number of samples requested by the SoapyFCDPP driver on each read of the Linux audio system. Smaller values mean smaller blocks of samples, delivered more often - which can help SDR applications to run more smoothly, as you have noticed.

The default value if not specifically set is sample_rate/4, which means the SDR gets samples delivered 4 times a second, leading to 'choppy' audio - I will look at changing this default I think..

SDR++ should also be able to adjust the period setting but I am not familiar with the UI so cannot tell you where and how to find this - sorry.

vasagle-gleblu commented 2 years ago

It points me in the right direction!

Thank you.

vasagle-gleblu commented 2 years ago

Any chance you could point me where to make this change to the default value so that I could compile it myself?

phlash commented 2 years ago

Sure, it's here: https://github.com/pothosware/SoapyFCDPP/blob/45fb07cf7167849e7e1864559487b15fe338744d/SoapyFCDPP/SoapyFCDPP.cpp#L28 If you know the display frame rate of your SDR, you can pop that in as the divisor.. for example, I use Gqrx at 10hz frame rate, so would set d_sample_rate/10 as a default. Good luck, have fun :grin:

vasagle-gleblu commented 1 year ago

FYI, I changed the divisor to 100. Worked like a charm.

Thank you.

vasagle-gleblu commented 1 year ago

1000 gave better performance. :P