[Hackrf-dev] GNU Radio and HackRF and Latency

[Mike Walters]

The issue is caused by large sample buffers, mainly the USB buffer size.

I've worked around it before by just patching gr-osmosdr and libhackrf to
use smaller buffers. This isn't a great fix because it will increase chance
of dropped samples at high rates. Here are the patches:

https://github.com/miek/gr-hubsan/blob/master/hackrf-16k-buffer.diff
https://github.com/miek/gr-hubsan/blob/master/gr-osmosdr-16k-buffer.diff

You may also need to play around with GNURadio max. buffers as discussed
here:

https://gnuradio.org/doc/doxygen/page_operating_fg.html#latency


On 4 December 2015 at 13:47, Mitja kocjančič <veso266 at gmail.com> wrote:

> Hi I am transmitting FM Modulated signal on 76 Mhz  and recieving it on my
> Sangean ATS 909X
>
> The signal is normal FM Radio signal with RDS and Stereo but for some
> reason there is 1 second delay (when I change song for instance it takes 1
> seconds for my Radio to notice that)
>
> Thats strange to me because I always thought that FM Modulation happens in
> real time and when you say something into microfone radio will pick
> it immediately.
>
> I know that 1 second delay happens with DAB (because you must encode audio
> and then decode it) but not on FM
>
> So could anybody be so kinf and tell me the reason why this delay happens
> and how to overcome this.
>
> Thanks for Anwsering and Best Regards
>
> _______________________________________________
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> HackRF-dev at greatscottgadgets.com
> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
>
>
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