diff options
Diffstat (limited to 'gr-atsc/src/lib/atsci_viterbi_decoder.cc')
| -rw-r--r-- | gr-atsc/src/lib/atsci_viterbi_decoder.cc | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/gr-atsc/src/lib/atsci_viterbi_decoder.cc b/gr-atsc/src/lib/atsci_viterbi_decoder.cc deleted file mode 100644 index 8804f6007..000000000 --- a/gr-atsc/src/lib/atsci_viterbi_decoder.cc +++ /dev/null @@ -1,176 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2002 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. - */ - -#include <atsci_viterbi_decoder.h> -#include <assert.h> -#include <stdio.h> -#include <cmath> -#include "atsci_viterbi_mux.cc" -#include <string.h> - - -/* How many separate Trellis encoders / Viterbi decoders run in parallel */ -static const int NCODERS = 12; - -static const float DSEG_SYNC_SYM1 = 5; -static const float DSEG_SYNC_SYM2 = -5; -static const float DSEG_SYNC_SYM3 = -5; -static const float DSEG_SYNC_SYM4 = 5; - -atsci_viterbi_decoder::atsci_viterbi_decoder () -{ - debug = true; - - /* - * These fifo's handle the alignment problem caused by the - * inherent decoding delay of the individual viterbi decoders. - * The net result is that this entire block has a pipeline latency - * of 12 complete segments. - * - * If anybody cares, it is possible to do it with less delay, but - * this approach is at least somewhat understandable... - */ - - // the -4 is for the 4 sync symbols - int fifo_size = ATSC_DATA_SEGMENT_LENGTH - 4 - viterbi[0].delay (); - for (int i = 0; i < NCODERS; i++) - fifo[i] = new fifo_t(fifo_size); - - reset (); -} - -atsci_viterbi_decoder::~atsci_viterbi_decoder () -{ - for (int i = 0; i < NCODERS; i++) - delete fifo[i]; -} - -void -atsci_viterbi_decoder::reset () -{ - for (int i = 0; i < NCODERS; i++){ - viterbi[i].reset (); - fifo[i]->reset (); - } -} - - -void -atsci_viterbi_decoder::decode (atsc_mpeg_packet_rs_encoded out[NCODERS], - const atsc_soft_data_segment in[NCODERS]) -{ - unsigned char out_copy[OUTPUT_SIZE]; - float in_copy[INPUT_SIZE]; - - // copy input into continguous temporary buffer - for (int i = 0; i < NCODERS; i++){ - assert (in[i].pli.regular_seg_p ()); - memcpy (&in_copy[i * INPUT_SIZE/NCODERS], - &in[i].data[0], - ATSC_DATA_SEGMENT_LENGTH * sizeof (in_copy[0])); - } - - memset (out_copy, 0, sizeof (out_copy)); // sanity check - - // do the deed... - decode_helper (out_copy, in_copy); - - // copy output from contiguous temp buffer into final output - for (int i = 0; i < NCODERS; i++){ - memcpy (&out[i].data[0], - &out_copy[i * OUTPUT_SIZE/NCODERS], - ATSC_MPEG_RS_ENCODED_LENGTH * sizeof (out_copy[0])); - - - // adjust pipeline info to reflect 12 segment delay - plinfo::delay (out[i].pli, in[i].pli, NCODERS); - } -} - -void -atsci_viterbi_decoder::decode_helper (unsigned char out[OUTPUT_SIZE], - const float symbols_in[INPUT_SIZE]) -{ - int encoder; - unsigned int i; - int dbi; - int dbwhere; - int dbindex; - int shift; - unsigned char dibit; - float symbol; - - /* Memset is not necessary if it's all working... */ - memset (out, 0, OUTPUT_SIZE); - -#define VERBOSE 0 - -#if 1 - /* Check for sync symbols in the incoming data stream */ - /* For now, all we do is complain to stdout. FIXME, pass it back to - caller as an error/quality signal. */ - for (i = 0; i < sync_symbol_indices_max; i++) { - int j = sync_symbol_indices[i]; - if (fabsf (symbols_in[j] - DSEG_SYNC_SYM1) > 1.0) - if (VERBOSE) fprintf (stderr, "** Missing dataseg sync 1 at %d, expect %g, got %g.\n", - j, DSEG_SYNC_SYM1, symbols_in[j]); - j++; - if (fabsf (symbols_in[j] - DSEG_SYNC_SYM2) > 1.0) - if (VERBOSE) fprintf (stderr, "** Missing dataseg sync 2 at %d, expect %g, got %g.\n", - j, DSEG_SYNC_SYM2, symbols_in[j]); - j++; - if (fabsf (symbols_in[j] - DSEG_SYNC_SYM3) > 1.0) - if (VERBOSE) fprintf (stderr, "** Missing dataseg sync 3 at %d, expect %g, got %g.\n", - j, DSEG_SYNC_SYM3, symbols_in[j]); - j++; - if (fabsf (symbols_in[j] - DSEG_SYNC_SYM4) > 1.0) - if (VERBOSE) fprintf (stderr, "** Missing dataseg sync 4 at %d, expect %g, got %g.\n", - j, DSEG_SYNC_SYM4, symbols_in[j]); - } -#endif -#undef VERBOSE - - // printf ("@@@ DIBITS @@@\n"); - - /* Now run each of the 12 Trellis encoders over their subset of - the input symbols */ - for (encoder = 0; encoder < NCODERS; encoder++) { - dbi = 0; /* Reinitialize dibit index for new encoder */ - fifo_t *dibit_fifo = fifo[encoder]; - - /* Feed all the incoming symbols into one encoder; - pump them into the relevant dibits. */ - for (i = 0; i < enco_which_max; i++) { - symbol = symbols_in[enco_which_syms[encoder][i]]; - dibit = dibit_fifo->stuff (viterbi[encoder].decode (symbol)); - // printf ("%d\n", dibit); - /* Store the dibit into the output data segment */ - dbwhere = enco_which_dibits[encoder][dbi++]; - dbindex = dbwhere >> 3; - shift = dbwhere & 0x7; - out[dbindex] = - (out[dbindex] & ~(0x03 << shift)) | (dibit << shift); - } /* Symbols fed into one encoder */ - } /* Encoders */ - - // fflush (stdout); -} |