Hi Federico and Jeff, thank you very much for your prompt answer. As I thought, it was a "newbie" mistake :-) I have modified my block according to what Federico has written and now it works.
Regards, Ralf Am 02.12.2021 um 12:31 schrieb Jeff Long:
[I just saw the response from Federico as I was writing this, so it's partly a duplicate] In work(), items are in terms of vectors, so you need to store off blk_size in the constructor. In work(), you would copy blk_size * noutput_items. For an example, take a look at the source for any of the built-in blocks that can take a vector, e.g., https://github.com/gnuradio/gnuradio/blob/master/gr-blocks/include/gnuradio/blocks/abs_blk.h https://github.com/gnuradio/gnuradio/blob/master/gr-blocks/lib/abs_blk_impl.h https://github.com/gnuradio/gnuradio/blob/master/gr-blocks/lib/abs_blk_impl.cc On Thu, Dec 2, 2021 at 5:26 AM Ralf Gorholt <ralf.gorh...@gmx.de> wrote: Dear all, I am quite new to GNU Radio and in order to see how GNU Radio blocks work I would like to create my own block that (for the moment) just copies complex data from the input to the output. This works as long as I copy only one number but not when I want to copy packets of numbers that come from the preceeding block. My block takes one parameter: blk_size. I would like to insert it in my DVB-T receiver flowgraph to analyze data (in a later step). I had a look at the square_ff example and other blocks to see how they are built but I still don't see what I am doing wrong. It must be a silly mistake. Perhaps you can help me? Here is the code: myblock_impl::myblock_impl(int blk_size) : gr::block("myblock", gr::io_signature::make(1, 1, blk_size * sizeof(gr_complex)), gr::io_signature::make(1, 1, blk_size * sizeof(gr_complex))) { } void myblock_impl::forecast(int noutput_items, gr_vector_int &ninput_items_required) { ninput_items_required[0] = noutput_items; } int myblock_impl::general_work(int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) { const gr_complex *in = (const gr_complex *) input_items[0]; gr_complex *out = (gr_complex *) output_items[0]; for (int i = 0; i < noutput_items; i++) { out[i] = in[i]; } consume_each(noutput_items); return noutput_items; } And the YML file: id: dl5eu_myblock label: myblock category: '[dl5eu]' templates: imports: import dl5eu make: dl5eu.myblock(${blk_size}) parameters: - id: blk_size label: Block size dtype: int default: '1' inputs: - label: in domain: stream dtype: complex vlen: ${blk_size} optional: '0' outputs: - label: out domain: stream dtype: complex vlen: ${blk_size} optional: '0' file_format: 1 Thank you very much for your help! Kind regards, Ralf
