diff options
| author | Bogdan Diaconescu <b_diaconescu@yahoo.com> | 2015-09-05 16:35:12 -0700 |
|---|---|---|
| committer | Ron Economos <w6rz@comcast.net> | 2015-09-05 16:35:12 -0700 |
| commit | 0b05c304f420196874f2a13bb21420a7609eb778 (patch) | |
| tree | 0247726280e3967bae9853062f721125ab58dd7a /gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc | |
| parent | 80d52551db67b2e80955eaadbbc63a54d4d4abbc (diff) | |
Add DVB-T receiver.
Diffstat (limited to 'gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc')
| -rw-r--r-- | gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc b/gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc new file mode 100644 index 0000000000..0358ada1ff --- /dev/null +++ b/gr-dtv/lib/dvbt/dvbt_convolutional_deinterleaver_impl.cc @@ -0,0 +1,137 @@ +/* -*- c++ -*- */ +/* + * Copyright 2015 Free Software Foundation, Inc. + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * This software is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this software; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gnuradio/io_signature.h> +#include "dvbt_convolutional_deinterleaver_impl.h" + +namespace gr { + namespace dtv { + + const int dvbt_convolutional_deinterleaver_impl::d_SYNC = 0x47; + const int dvbt_convolutional_deinterleaver_impl::d_NSYNC = 0xB8; + const int dvbt_convolutional_deinterleaver_impl::d_MUX_PKT = 8; + + dvbt_convolutional_deinterleaver::sptr + dvbt_convolutional_deinterleaver::make(int nsize, int I, int M) + { + return gnuradio::get_initial_sptr + (new dvbt_convolutional_deinterleaver_impl(nsize, I, M)); + } + + /* + * The private constructor + */ + dvbt_convolutional_deinterleaver_impl::dvbt_convolutional_deinterleaver_impl(int blocks, int I, int M) + : block("dvbt_convolutional_deinterleaver", + io_signature::make(1, 1, sizeof (unsigned char)), + io_signature::make(1, 1, sizeof (unsigned char) * I * blocks)), + d_blocks(blocks), d_I(I), d_M(M) + { + set_relative_rate(1.0 / d_I * d_blocks); + set_output_multiple(2); + //The positions are shift registers (FIFOs) + //of length i*M + for (int i = (d_I - 1); i >= 0; i--) { + d_shift.push_back(new std::deque<unsigned char>(d_M * i, 0)); + } + + // There are 8 mux packets + assert(d_blocks / d_M == d_MUX_PKT); + } + + /* + * Our virtual destructor. + */ + dvbt_convolutional_deinterleaver_impl::~dvbt_convolutional_deinterleaver_impl() + { + for (unsigned int i = 0; i < d_shift.size(); i++) { + delete d_shift.back(); + d_shift.pop_back(); + } + } + + void + dvbt_convolutional_deinterleaver_impl::forecast (int noutput_items, gr_vector_int &ninput_items_required) + { + int ninputs = ninput_items_required.size (); + + for (int i = 0; i < ninputs; i++) { + ninput_items_required[i] = noutput_items * d_I * d_blocks; + } + } + + + int + dvbt_convolutional_deinterleaver_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 unsigned char *in = (const unsigned char *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + int to_out = noutput_items; + + /* + * Look for a tag that signals superframe_start and consume all input items + * that are in input buffer so far. + * This will actually reset the convolutional deinterleaver + */ + std::vector<tag_t> tags; + const uint64_t nread = this->nitems_read(0); //number of items read on port 0 + this->get_tags_in_range(tags, 0, nread, nread + (noutput_items * d_I * d_blocks), pmt::string_to_symbol("superframe_start")); + + if (tags.size()) { + if (tags[0].offset - nread) { + consume_each(tags[0].offset - nread); + return (0); + } + } + + /* + * At this moment the first item in input buffer should be NSYNC or SYNC + */ + + for (int count = 0, i = 0; i < to_out; i++) { + for (int mux_pkt = 0; mux_pkt < d_MUX_PKT; mux_pkt++) { + // This is actually the deinterleaver + for (int k = 0; k < (d_M * d_I); k++) { + d_shift[k % d_I]->push_back(in[count]); + out[count++] = d_shift[k % d_I]->front(); + d_shift[k % d_I]->pop_front(); + } + } + } + + // Tell runtime system how many input items we consumed on + // each input stream. + consume_each(d_I * d_blocks * to_out); + + // Tell runtime system how many output items we produced. + return (to_out); + } + + } /* namespace dtv */ +} /* namespace gr */ + |