int work(int noutput_items,
	   gr_vector_const_void_star &input_items,
	   gr_vector_void_star &output_items)
  {
    const std::complex<float> *in = reinterpret_cast<const std::complex<float> *>(input_items[0]);
    float *out = reinterpret_cast<float *>(output_items[0]);
    gruel::high_res_timer_type t1, t2, tit;
    
    t1 = gruel::high_res_timer_now();

    for(int i = 0; i < noutput_items; i++){
      std::complex<float> product = in[i+1] * conj(in[i]);
      out[i] = d_gain * gr_fast_atan2f(imag(product), real(product));
    }

    t2 = gruel::high_res_timer_now();

    tit = t2 - t1;

    printf(">> time to demod one [%d] buffer: %lld ticks\n", noutput_items, tit);

    return noutput_items;
  }