Re: [Discuss-gnuradio] call the work() method

[xianda]

Hi:
      Thank you so much.
      For example,I write a simple c++ program which can use the "gnuradio/fft/fft.h".But i also want to use <gnuradio/digital/ofdm_cyclic_prefixer.h>.
      But the ofdm_cyclic_prefixer is a block.It has work function.
      I attached my document.
      #include <fstream>
#include <vector>
#include <gnuradio/gr_complex.h>
#include <gnuradio/fft/fft.h>
#include <gnuradio/digital/ofdm_cyclic_prefixer.h>

std::vector<std::complex<float> *> buff1(64);//read data
std::vector<std::complex<float> *> buff2(64);//write data

std::ifstream infile("a.dat",std::ifstream::binary);
std::ofstream outfile("b.dat",std::ofstream::binary);

int main(){
while(not infile.eof())
{
infile.read((char*)&buff1.front(),buff1.size()*sizeof(std::complex<float>));

gr::fft::fft_complex *buff=new gr::fft::fft_complex(64,0);
gr_complex *bu=buff->get_inbuf();
memcpy(bu,&buff1.front(),buff1.size()*sizeof(std::complex<float>));
buff->execute();
gr_complex *out=buff->get_outbuf();
memcpy(&buff2.front(),out,buff2.size()*sizeof(std::complex<float>));

outfile.write((char*)&buff2.front(),buff2.size()*sizeof(std::complex<float>));
}

infile.close();
outfile.close();
}
    Can you help me?
    Thanks
Best regards,
xianda

At 2014-05-31 05:56:29, "Marcus Müller" <address@hidden> wrote:
>   
>     
>   
>   
>     Hi Xianda,
>     
> >          I know every block should have it's work or general_work function.And i know it's used by scheduler.
> >     
>     Right! 
> >          Now I want to write my c++ code just call work function.Is right to do it?
> >     
>     I hope I understand you correctly:
>     You want to write a C++ program that calls your work function?
>     
>     As usual, it would be quite helpful if you explained *why* you would
>     want to do this!
>     
>     Short Answer:
>     *Usually* you don't do that, so it's not right to do.
>     Long Answer:
>     You can not generally do this because a block can only exist within
>     GNU Radio, and relies on GNU Radio scheduler mechanisms. 
>     If you however, wrote a work() that only uses the the input_items,
>     output_items buffers and only relies on noutput_items as runtime
>     information,
>     than that's technically possible. I would *not* recommend that,
>     though. Better write a new function, e.g. "signal_processing(in,out,
>     howmany)" in a non-block class
>     and call that from your work() as well as from your new C++ program.
> >          If ok,can someone explain how to call work function?
> >     
>     It's a C++ method, and the function signature is 
>     int work
>     (int noutput_items, gr_vector_const_void_star
>     &input_items, gr_vector_void_star
>     &output_items)
>     (from the official documentation,
>     http://gnuradio.org/doc/doxygen/classgr_1_1sync__block.html)
>     You could call it like you would call every other method. Since I
>     assume you already know how input_ and output_items should look like
>     from writing a work() function,
>     I don't understand where the "how to call question" comes from.
>     
>     Best Regards,
>     Marcus Müller
>