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
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