[Discuss-gnuradio] Examples of Python code using 'current_tags' function for Tag Debug block

2019-09-02 Thread Marcus D. Leech
The subject pretty-much says it all. I'm looking for a Python example of code that uses the 'current_tags' function for the Tag Debug block, and picks apart the resulting tag(s). In Python land are the tags just a tuple/list or a dictionary? I've snarfled through the generated SWIG code, and

Re: [Discuss-gnuradio] Building GNU Radio on Fedora 30 with pybomb to get a 3.8 installation

2019-09-02 Thread Vasil Velichkov
Hi Barry, On 02/09/2019 12.12, Barry Scott wrote: > > >> On 1 Sep 2019, at 19:20, jean-michel.fri...@femto-st.fr wrote: >> >>> pybombs prefix init ~/gnuradio -R gnuradio-default >> >> gnuradio-default.lwr recipe is 3.7. Edit the recipe in >> .pybombs/recipes/gr-recipes >> and replace gnuradio w

Re: [Discuss-gnuradio] Maximum input items consumed on each input stream

2019-09-02 Thread Adrian Musceac
Thank you all for your comments. Marcus, I'd just like to say that I have been using the packet encoder/decoder for a long time (3-4 years) and could not see any issues that could be attributed to it. Regarding the dropped samples, is it the case that the buffers are continuously grown as the s

Re: [Discuss-gnuradio] Maximum input items consumed on each input stream

2019-09-02 Thread CEL
I second what Michael wrote, but I'd like to be more general: GNU Radio does NOT drop samples, anywhere. SDR or audio or similar analog/digital hardware might do that when buffers run over. There's a long-standing, and seemingly unfixable bug in the packet_encoder/decoder Python hier blocks that

Re: [Discuss-gnuradio] ffast-math

2019-09-02 Thread CEL
-ffast-math is allowed to reorder calculations, e.g. it can do a*f + b*f + c*f as (a+b+c)*f (or vice versa) which of course isn't necessarily the same result, and can lead to numerical instability. The problem is really that for some kernels, things like zero-signage and NaN / Inf handling / r

Re: [Discuss-gnuradio] ffast-math

2019-09-02 Thread Albin Stigö
ffast-math disables signed zero by design I think... I'm particularly interested in problems of numeric stability and loss of dynamic range. --Albin On Mon, Sep 2, 2019, 15:27 Johannes Demel wrote: > Hi Albin, > > one of my students reported a little oddity about `-ffast-math`. Assume > you w

Re: [Discuss-gnuradio] ffast-math

2019-09-02 Thread Johannes Demel
Hi Albin, one of my students reported a little oddity about `-ffast-math`. Assume you want to set a float to -0, i.e. set the sign bit only. In this case `-ffast-math` seems to remove the sign bit. In VOLK this might be an issue with `_mm256_conjugate_ps` in `include/volk/volk_avx_intrinsics.h

Re: [Discuss-gnuradio] Maximum input items consumed on each input stream

2019-09-02 Thread Michael Dickens
Hi Adrian - If you use a file source with a throttle, then that section of your flowgraph will not drop samples. Using what Kevin wrote: The file source will "work" as fast as possible, so its output buffer will fill up quickly and any time samples are removed from it & so long as there is file dat

Re: [Discuss-gnuradio] Maximum input items consumed on each input stream

2019-09-02 Thread Adrian Musceac
Hi Kevin, Thanks for the explanation, I think my flawed understading was due to the fact of having a file source with a throttle block, and seeing samples being dropped from buffers that did not match ASCII bytes lost at the file source but somewhere along the way. Is it correct to presume that in

Re: [Discuss-gnuradio] Building GNU Radio on Fedora 30 with pybomb to get a 3.8 installation

2019-09-02 Thread Barry Scott
> On 1 Sep 2019, at 19:20, jean-michel.fri...@femto-st.fr wrote: > >> pybombs prefix init ~/gnuradio -R gnuradio-default > > gnuradio-default.lwr recipe is 3.7. Edit the recipe in > .pybombs/recipes/gr-recipes > and replace gnuradio with (in order to call gnuradio38.lwr) > depends: >-