John, I can't speak to VirtualBox, but I use vmware and have never had problems with RTLSDR dropping samples; I've also used LimeSDR at higher bandwidths just fine, with a 4 year old machine.
Choppy audio is generally due to default ALSA settings. Check this out: http://sdrgps.blogspot.com/2016/01/gnuradio-getting-audio-to-work-in-vm.html philip hahn On Tue, Jan 23, 2018 at 4:58 AM, john cooper <[email protected]> wrote: > Thanks! Really appreciated. John > > On Tue, 23 Jan 2018, 12:57 Müller, Marcus (CEL), <[email protected]> wrote: > >> You'll find instructions at >> https://osmocom.org/projects/sdr/wiki/rtl-sdr#rtl_tcp >> >> On Tue, 2018-01-23 at 12:50 +0000, john cooper wrote: >> > Hello Marcus, good idea, I will research how to do this and report >> back. Many thanks. John >> > >> > On Tue, 23 Jan 2018, 12:47 Müller, Marcus (CEL), <[email protected]> >> wrote: >> > > Ah, and: Choppy audio from low-buffer streaming applications within >> VMs >> > > is another common issue with many VM hypervisors. >> > > On Tue, 2018-01-23 at 12:44 +0000, Müller, Marcus (CEL) wrote: >> > > > Hi John, >> > > > >> > > > my experience, indeed, is that USB passthrough support in VMs is >> > > > suboptimal. So, this could very well be a virtual USB host >> controller >> > > > problem. >> > > > >> > > > I'd actually recommend circumventing the issue, e.g. by running >> rtl_tcp >> > > > on the host machine, and using the appropriate source string in the >> gr- >> > > > osmosdr source. >> > > > >> > > > Best regards, >> > > > Marcus >> > > > >> > > > On Tue, 2018-01-23 at 12:40 +0000, john cooper wrote: >> > > > > Hello GNU people, some help greatly appreciated. >> > > > > >> > > > > I am a newbie to GNU Radio and have a lost samples problem, lost >> from the USB 2 RF device, seemingly not in the Flowgraph signal chain. >> > > > > >> > > > > Although I have no hard evidence I am coming to the point of >> suspecting the problem lies with the running of GNU under Oracle VM, >> hosted by Win 10. >> > > > > >> > > > > Physical RF device is a DVB-T+DAB+FM USB dongle, with Realtek >> RTL2832U and the R820 device. >> > > > > >> > > > > System is GNU Radio ( latest version ) running as a guest under >> Oracle VM, hosted by Win 10 Pro on a machine with significant system >> resources. >> > > > > >> > > > > Oracle version is VM 5.2.6r >> > > > > >> > > > > Problem is *always* dropped samples from a DVB-T+DAB+FM USB >> dongle, tens to hundreds of lost samples. >> > > > > >> > > > > I have done the following :- >> > > > > >> > > > > Added my name to the virtualbox users list. >> > > > > >> > > > > added the Virtual Box Extension Pack 5.2.6 to allow USB 2 >> support in the VM >> > > > > >> > > > > Selected USB2 in the Oracle VM machine. >> > > > > >> > > > > Blacklisted the RTL2338 DVB-T driver via >> /etc/modprobe.d/blacklist-rtl.conf etc. >> > > > > >> > > > > Tested with rtl_test with sample speeds from 2.4e6 down to >> 0.25 e6 >> > > > > >> > > > > Several Flowgraphs of various example FM broadcast receivers >> all have choppy audio, believed to be due to lost sample from the RF device >> via USB2 and not seemingly due to mismatch of audio sing sample rates. >> > > > > >> > > > > >> > > > > Using only the RTL_SDR source block and Low Pass Filter, plus the >> WX GUI FFT Sink and the WX GUI Scope Sink, in a FlowGraph produces spikes >> in the Audio which coincide with the suggested sample losses from the >> physical dongle. >> > > > > >> > > > > >> > > > > Under any and all tests and sample rates the result of rtl_test >> when ran in the terminal is a continual stream of lost samples. >> > > > > >> > > > > >> > > > > Other information; >> > > > > >> > > > > running SDR# via the host system ( Win 10 Pro ) is faultless at >> 2.4e6 sample speed and all lower speeds. >> > > > > >> > > > > I have also installed Gqrx in the VM and this system stalls with >> the Terminal screen failing to enter the initial set up dialogue screen but >> does list in the terminal screen the list of parameters, then hangs. >> > > > > >> > > > > If anyone has input to the problem, I would be very pleased to >> hear back and offer my thanks in advance. >> > > > > >> > > > > John >> > > > > >> > > > > >> > > > > Virus-free. www.avg.com >> > > > > _______________________________________________ >> > > > > Discuss-gnuradio mailing list >> > > > > [email protected] >> > > > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > > > >> > > > _______________________________________________ >> > > > Discuss-gnuradio mailing list >> > > > [email protected] >> > > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >
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