Thank you very much Marcus, Michael, Abin, and Ron, really appreciate your responses. To give some context, I just started designing a prototype reader to implement a custom protocol for backscatter neural implants; very excited to build my platform with GNU-radio :)
After reading all the information from your responses and links provided, I still have a problem with my implementation. According to the buffer sizes that you mentioned, I should not have this problem, but I think I am missing something. I may need to re-design my system/flow-graph, but I would like to get a last advice/help, if possible. Thanks in advance! *I want my block Decoder to consume_each(>8900) but I get overflows "D" messages. See details below* I have 2 general out of tree blocks: Gate and Decoder. They both have*:* * ninput_items_required[0] = noutput_items;* * const gr_complex *in = (const gr_complex *) input_items[0];* * gr_complex *out = (gr_complex *) output_items[0]; * The flow-graph looks like *uhd_source -> fir_filter_ccc -> Gate -> Decoder -> other blocks. (Using a USRP N210 + SBX)* The idea is that I want the block *Decoder* to only process the input samples when I have received *k* samples. Let's set k=~8900 So, at the *Decoder* block general_work(), I set *consume_each(0) *until *ninput_items[0]>=k.* Basically, at the Decoder general_work() I have the following (just a overview, not pseudo-code): * if (ninput_items[0] <k)* * //do nothing* * //consume_each(0)* *else* * // process the input samples* * //consume_each(k)* My problem is that if I set k~8900 *, I get 'D' messages on the terminal. * And one interesting? thing happens. When *ninput_items[0]* gets close to *k=8500* (or higher value), is when I start getting 'D', and after that *ninput_items[0] = 800*, no matter the value of *k*. Thank you. Cheers Laura. On Fri, Aug 30, 2019 at 7:29 AM Müller, Marcus (CEL) <muel...@kit.edu> wrote: > Hi Ron, > > just because I think this might be interesting to people dealing with > really high rates: > The maximum size is typically limited by the size of mmap'able memory > that you can allocate; that depends on the circular buffer factory > used: > For the posix shared memory thing, I don't think anything is stopping > you from using "memory space size" order amounts of buffer. > For anonymous file-backed mmap'ed buffers, I'd expect that we haven't > addressed the possibility of using more than 32 bit addresses, so > somewhere around 2 GB you'd find your upper limit. > > Best regards, > Marcus > > On Fri, 2019-08-30 at 06:20 -0700, Ron Economos wrote: > > Just to put a number on this question, the DVB-T2 transmitter uses up to > 16 Megabyte buffers between blocks. I'm not sure what the absolute maximum > is, but 16 Megabytes should cover most applications. > > The DVB-T2 blocks use set_output_multiple() in conjunction with > forecast() to allocate these large buffers. > > Ron > > On 8/28/19 11:46, Laura Arjona wrote: > > > Hello GNURadio community, > > > > > > Does anyone know what is the maximum number of input items that an Out > Of Tree block can consume on each input stream? > > > > > > consume_each(consumed) --> what is the maximum value that the variable > consumed can take? > > > > > > Thank you very much. > > > > > > > > > -- > > > Laura Arjona > > > Washington Research Foundation Innovation Postdoctoral Fellow in > Neuroengineering > > > > > > Paul G. Allen School of Computer Science & Engineering > > > 185 E Stevens Way NE > > > University of Washington > > > Seattle, WA 98195-2350 > > > > > > > > > _______________________________________________ > > > 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 > -- *Laura Arjona * Washington Research Foundation Innovation Postdoctoral Fellow in Neuroengineering *Paul G. Allen School of Computer Science & Engineering* 185 E Stevens Way NE University of Washington Seattle, WA 98195-2350
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