3 * Copyright 2005 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
24 * WARNING: This file is automatically generated by generate_gr_fft_filter_XXX.py
25 * Any changes made to this file will be overwritten.
32 #include <gr_fft_filter_ccc.h>
33 #include <gr_io_signature.h>
38 #include <gr_firdes.h>
43 gr_fft_filter_ccc_sptr gr_make_fft_filter_ccc (int decimation, const std::vector<gr_complex> &taps)
45 return gr_fft_filter_ccc_sptr (new gr_fft_filter_ccc (decimation, taps));
49 gr_fft_filter_ccc::gr_fft_filter_ccc (int decimation, const std::vector<gr_complex> &taps)
50 : gr_sync_decimator ("fft_filter_ccc",
51 gr_make_io_signature (1, 1, sizeof (gr_complex)),
52 gr_make_io_signature (1, 1, sizeof (gr_complex)),
54 d_fftsize(-1), d_fwdfft(0), d_invfft(0), d_updated(false)
56 // if (decimation != 1)
57 // throw std::invalid_argument("gr_fft_filter_ccc: decimation must be 1");
60 actual_set_taps(taps);
63 gr_fft_filter_ccc::~gr_fft_filter_ccc ()
71 print_vector_complex(const std::string label, const std::vector<gr_complex> &x)
74 for (unsigned i = 0; i < x.size(); i++)
75 std::cout << x[i] << " ";
81 gr_fft_filter_ccc::set_taps (const std::vector<gr_complex> &taps)
88 * determines d_ntaps, d_nsamples, d_fftsize, d_xformed_taps
91 gr_fft_filter_ccc::actual_set_taps (const std::vector<gr_complex> &taps)
94 compute_sizes(taps.size());
96 d_tail.resize(tailsize());
97 for (i = 0; i < tailsize(); i++)
100 gr_complex *in = d_fwdfft->get_inbuf();
101 gr_complex *out = d_fwdfft->get_outbuf();
103 float scale = 1.0 / d_fftsize;
105 // Compute forward xform of taps.
106 // Copy taps into first ntaps slots, then pad with zeros
107 for (i = 0; i < d_ntaps; i++)
108 in[i] = taps[i] * scale;
110 for (; i < d_fftsize; i++)
113 d_fwdfft->execute(); // do the xform
115 // now copy output to d_xformed_taps
116 for (i = 0; i < d_fftsize; i++)
117 d_xformed_taps[i] = out[i];
119 //print_vector_complex("transformed taps:", d_xformed_taps);
122 // determine and set d_ntaps, d_nsamples, d_fftsize
125 gr_fft_filter_ccc::compute_sizes(int ntaps)
127 int old_fftsize = d_fftsize;
129 d_fftsize = (int) (2 * pow(2.0, ceil(log(ntaps) / log(2))));
130 d_nsamples = d_fftsize - d_ntaps + 1;
133 fprintf(stderr, "gr_fft_filter: ntaps = %d, fftsize = %d, nsamples = %d\n",
134 d_ntaps, d_fftsize, d_nsamples);
136 assert(d_fftsize == d_ntaps + d_nsamples -1 );
138 if (d_fftsize != old_fftsize){ // compute new plans
141 d_fwdfft = new gri_fft_complex(d_fftsize, true);
142 d_invfft = new gri_fft_complex(d_fftsize, false);
143 d_xformed_taps.resize(d_fftsize);
146 set_output_multiple(d_nsamples);
150 gr_fft_filter_ccc::work (int noutput_items,
151 gr_vector_const_void_star &input_items,
152 gr_vector_void_star &output_items)
154 gr_complex *in = (gr_complex *) input_items[0];
155 gr_complex *out = (gr_complex *) output_items[0];
158 actual_set_taps(d_new_taps);
160 return 0; // output multiple may have changed
163 assert(noutput_items % d_nsamples == 0);
167 int ninput_items = noutput_items * decimation();
169 for (int i = 0; i < ninput_items; i += d_nsamples){
171 memcpy(d_fwdfft->get_inbuf(), &in[i], d_nsamples * sizeof(gr_complex));
173 for (j = d_nsamples; j < d_fftsize; j++)
174 d_fwdfft->get_inbuf()[j] = 0;
176 d_fwdfft->execute(); // compute fwd xform
178 gr_complex *a = d_fwdfft->get_outbuf();
179 gr_complex *b = &d_xformed_taps[0];
180 gr_complex *c = d_invfft->get_inbuf();
182 for (j = 0; j < d_fftsize; j++) // filter in the freq domain
185 d_invfft->execute(); // compute inv xform
187 // add in the overlapping tail
189 for (j = 0; j < tailsize(); j++)
190 d_invfft->get_outbuf()[j] += d_tail[j];
192 // copy nsamples to output
194 //memcpy(out, d_invfft->get_outbuf(), d_nsamples * sizeof(gr_complex));
198 while (j < d_nsamples) {
199 *out++ = d_invfft->get_outbuf()[j];
202 dec_ctr = (j - d_nsamples);
205 memcpy(&d_tail[0], d_invfft->get_outbuf() + d_nsamples,
206 tailsize() * sizeof(gr_complex));
209 assert((out - (gr_complex *) output_items[0]) == noutput_items);
210 assert(dec_ctr == 0);
212 return noutput_items;