-/*
- * determines d_ntaps, d_nsamples, d_fftsize, d_xformed_taps
- */
-void
-gr_fft_filter_fff::actual_set_taps (const std::vector<float> &taps)
-{
- int i = 0;
- compute_sizes(taps.size());
-
- d_tail.resize(tailsize());
- for (i = 0; i < tailsize(); i++)
- d_tail[i] = 0;
-
- float *in = d_fwdfft->get_inbuf();
- gr_complex *out = d_fwdfft->get_outbuf();
-
- float scale = 1.0 / d_fftsize;
-
- // Compute forward xform of taps.
- // Copy taps into first ntaps slots, then pad with zeros
- for (i = 0; i < d_ntaps; i++)
- in[i] = taps[i] * scale;
-
- for (; i < d_fftsize; i++)
- in[i] = 0;
-
- d_fwdfft->execute(); // do the xform
-
- // now copy output to d_xformed_taps
- for (i = 0; i < d_fftsize/2+1; i++)
- d_xformed_taps[i] = out[i];
-
- //print_vector_complex("transformed taps:", d_xformed_taps);
-}
-
-// determine and set d_ntaps, d_nsamples, d_fftsize
-
-void
-gr_fft_filter_fff::compute_sizes(int ntaps)
-{
- int old_fftsize = d_fftsize;
- d_ntaps = ntaps;
- d_fftsize = (int) (2 * pow(2.0, ceil(log(ntaps) / log(2))));
- d_nsamples = d_fftsize - d_ntaps + 1;
-
- if (0)
- fprintf(stderr, "gr_fft_filter: ntaps = %d, fftsize = %d, nsamples = %d\n",
- d_ntaps, d_fftsize, d_nsamples);
-
- assert(d_fftsize == d_ntaps + d_nsamples -1 );
-
- if (d_fftsize != old_fftsize){ // compute new plans
- delete d_fwdfft;
- delete d_invfft;
- d_fwdfft = new gri_fft_real_fwd(d_fftsize);
- d_invfft = new gri_fft_real_rev(d_fftsize);
- d_xformed_taps.resize(d_fftsize/2+1);
- }
-
- set_output_multiple(d_nsamples);
-}
-