I think it's going wrong in getActionFromSize, which easy as it looks[1], I don't get the hang of. Why do we need a specific QAction based on the FFT length we're setting? And why does an FFT size of 4 lead to negative indices in a QList?
Anyway, the actual bug was on my side, as I was constantly setting an FFT size of 4. Which seemingly doesn't work. @LD: try <callback>set_fft_size(max(int($fftsize),32))</callback> instead. I was then able to change the displayed FFT on the fly using QT Gui sliders [2]. Greetings, Marcus [1] gr-qtgui/include/gnuradio/qtgui/form_menus.h [2] https://gist.github.com/marcusmueller/edfef568a92821261f9f , the adjustable_qtgui_fft.grc file should load nicely in a 3.7.4 GNU Radio, I think it should work with 3.7.x On 04.06.2014 09:21, Marcus Müller wrote: > Hi! > > Alfredo: Jep, did that. GDB was how I figured out things went wrong in > FreqDisplayForm::setFFTSize() in the first place :). > Jörg: Interesting; but the error is quite reproducibly at the same > place; I'll try to set a breakpoint at the kernel call and see if that > happens again. But that will require some gdb magic (so that GDB only > interrupts program flow when the fft size changes), and that's > definitively something that would be worthwhile to learn, however I'm > postponing this for now for reasons of time available. > > Greetings, > Marcus > > On 04.06.2014 08:48, Jan Krämer wrote: >> Hey, >> >> I know another GSoC Student has problems with the a GT GUI sink as >> well. It would randomly SEGFAULT in a volk multiply kernel. I think it >> is the volk_32_fc_32f_multiply_32fc kernel used in >> waterfall_sink_X_impl::fft(). This kernel takes the FFT size as an >> input argument, so it could be related to your problem. I just had a >> quick glance at it so I am not sure though. I'll ask him to post his >> exact problem when he arrives at the lab. Maybe he can shed a bit more >> light on this problem >> >> -Jan >> >> >> On 04.06.2014 01:43, Alfredo Muniz wrote: >>> On Tue, Jun 3, 2014 at 4:35 PM, Marcus Müller <mar...@hostalia.de >>> <mailto:mar...@hostalia.de>> wrote: >>> >>> I hope someone more familiar with the qtgui infrastructure might >>> chime in. >>> >>> >>> Hey Marcus, >>> >>> Did you try debugging the SEGFAULT using gdb? This is a good >>> reference to try: >>> http://www.unknownroad.com/rtfm/gdbtut/gdbsegfault.html >>> >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
