diff options
Diffstat (limited to 'gr-atsc/lib/atsc_field_sync_mux.cc')
| -rw-r--r-- | gr-atsc/lib/atsc_field_sync_mux.cc | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/gr-atsc/lib/atsc_field_sync_mux.cc b/gr-atsc/lib/atsc_field_sync_mux.cc new file mode 100644 index 0000000000..578af9eff1 --- /dev/null +++ b/gr-atsc/lib/atsc_field_sync_mux.cc @@ -0,0 +1,203 @@ +/* -*- c++ -*- */ +/* + * Copyright 2006,2010 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio 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. + * + * GNU Radio 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 GNU Radio; 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 <atsc/field_sync_mux.h> +#include <gr_io_signature.h> +#include <atsc/consts.h> +#include <atsc/pnXXX_impl.h> + + +atsc_field_sync_mux_sptr +atsc_make_field_sync_mux() +{ + return gnuradio::get_initial_sptr(new atsc_field_sync_mux()); +} + +atsc_field_sync_mux::atsc_field_sync_mux() + : gr_sync_block("atsc_field_sync_mux", + gr_make_io_signature(1, 1, sizeof(atsc_data_segment)), + gr_make_io_signature(1, 1, sizeof(atsc_data_segment))) +{ + reset(); +} + +static const int NUMBER_OF_OUTPUTS = 1; // # of output streams (almost always one) + +static const int N_SAVED_SYMBOLS = atsc_field_sync_mux::N_SAVED_SYMBOLS; + +static void +init_field_sync_common (unsigned char *p, int mask, + const unsigned char saved_symbols[N_SAVED_SYMBOLS]) +{ + static const unsigned char bin_map[2] = { 1, 6 }; // map binary values to 1 of 8 levels + + int i = 0; + + p[i++] = bin_map[1]; // data segment sync pulse + p[i++] = bin_map[0]; + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + + for (int j = 0; j < 511; j++) // PN511 + p[i++] = bin_map[atsc_pn511[j]]; + + for (int j = 0; j < 63; j++) // PN63 + p[i++] = bin_map[atsc_pn63[j]]; + + for (int j = 0; j < 63; j++) // PN63, toggled on field 2 + p[i++] = bin_map[atsc_pn63[j] ^ mask]; + + for (int j = 0; j < 63; j++) // PN63 + p[i++] = bin_map[atsc_pn63[j]]; + + p[i++] = bin_map[0]; // 24 bits of VSB8 mode identifiera + p[i++] = bin_map[0]; + p[i++] = bin_map[0]; + p[i++] = bin_map[0]; + + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + + p[i++] = bin_map[1]; + p[i++] = bin_map[1]; + p[i++] = bin_map[1]; + p[i++] = bin_map[1]; + + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + p[i++] = bin_map[1]; + p[i++] = bin_map[0]; + + + for (int j = 0; j < 92; j++) // 92 more bits + p[i++] = bin_map[atsc_pn63[j % 63]]; + + // now copy the last 12 symbols of the previous segment + + for (int j = 0; j < N_SAVED_SYMBOLS; j++) + p[i++] = saved_symbols[j]; + + assert (i == ATSC_DATA_SEGMENT_LENGTH); +} +inline static void +init_field_sync_1 (atsc_data_segment *s, + const unsigned char saved_symbols[N_SAVED_SYMBOLS]) +{ + init_field_sync_common (&s->data[0], 0, saved_symbols); +} + +inline static void +init_field_sync_2 (atsc_data_segment *s, + const unsigned char saved_symbols[N_SAVED_SYMBOLS]) + +{ + init_field_sync_common (&s->data[0], 1, saved_symbols); +} + +static void +save_last_symbols (unsigned char saved_symbols[N_SAVED_SYMBOLS], + const atsc_data_segment &seg) +{ + for (int i = 0; i < N_SAVED_SYMBOLS; i++) + saved_symbols[i] = seg.data[i + ATSC_DATA_SEGMENT_LENGTH - N_SAVED_SYMBOLS];} + + +inline static bool +last_regular_seg_p (const plinfo &pli) +{ + return pli.regular_seg_p () && (pli.segno () == ATSC_DSEGS_PER_FIELD - 1); +} + +void +atsc_field_sync_mux::forecast (int noutput_items, gr_vector_int &ninput_items_required) +{ + unsigned ninputs = ninput_items_required.size(); + for (unsigned i = 0; i < ninputs; i++) + ninput_items_required[i] = fixed_rate_noutput_to_ninput (noutput_items); + +} + + +int +atsc_field_sync_mux::work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const atsc_data_segment *in = (const atsc_data_segment *) input_items[0]; + atsc_data_segment *out = (atsc_data_segment *) output_items[0]; + + unsigned int index = 0; + for (int outdex = 0; outdex < noutput_items; outdex++){ + + assert (in[index].pli.regular_seg_p ()); + + if (!in[index].pli.first_regular_seg_p ()){ + out[outdex] = in[index]; // just copy in to out + + if (last_regular_seg_p (in[index].pli)) + save_last_symbols (d_saved_symbols, in[index]); + + index++; + } + else { // first_regular_seg_p + if (!d_already_output_field_sync){ + // write out field sync... + atsc_data_segment field_sync; + + if (in[index].pli.in_field1_p ()) + init_field_sync_1 (&field_sync, d_saved_symbols); + else + init_field_sync_2 (&field_sync, d_saved_symbols); + + // note that index doesn't advance in this branch + out[outdex] = field_sync; + d_already_output_field_sync = true; + } + else { + // already output field sync, now output first regular segment + out[outdex] = in[index]; + index++; + d_already_output_field_sync = false; + } + } + } + + d_current_index += index; + + return noutput_items; +} |