diff options
Diffstat (limited to 'gr-atsc/src/lib/GrAtscFieldSyncDemux.cc')
| -rw-r--r-- | gr-atsc/src/lib/GrAtscFieldSyncDemux.cc | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc b/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc new file mode 100644 index 000000000..04a39bd06 --- /dev/null +++ b/gr-atsc/src/lib/GrAtscFieldSyncDemux.cc @@ -0,0 +1,173 @@ +/* -*- 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 2, 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., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#include <cmath> +#include <GrAtscFieldSyncDemux.h> +#include <atsc_consts.h> +#include <atsc_types.h> +#include <atsci_syminfo.h> +#include <stdio.h> +#include <assert.h> + +using std::abs; + +static const int DEC = ATSC_DATA_SEGMENT_LENGTH; // nominal decimation factor + +GrAtscFieldSyncDemux::GrAtscFieldSyncDemux () + : VrDecimatingSigProc<float,atsc_soft_data_segment> (1, DEC), + d_locked (false), d_in_field2(true), d_segment_number(0), d_next_input(0), + d_lost_index (0) +{ + history = 2 * ATSC_DATA_SEGMENT_LENGTH; // spare input samples in case we need them. +} + +GrAtscFieldSyncDemux::~GrAtscFieldSyncDemux () +{ +} + +int +GrAtscFieldSyncDemux::forecast (VrSampleRange output, + VrSampleRange inputs[]) { + /* dec:1 ratio with history */ + + assert (numberInputs == 2); + + for (unsigned int i = 0; i < numberInputs; i++) { + inputs[i].index = d_next_input; + inputs[i].size = output.size * decimation + history - 1; + } + return 0; +} + +inline static bool +tag_is_seg_sync_or_field_sync (atsc::syminfo tag) +{ + return tag.symbol_num == 0 && tag.valid; +} + +int +GrAtscFieldSyncDemux::work (VrSampleRange output, void *ao[], + VrSampleRange inputs[], void *ai[]) +{ + float *input_samples = (float *) ai[0]; + atsc::syminfo *input_tags = (atsc::syminfo *) ai[1]; + atsc_soft_data_segment *out = ((atsc_soft_data_segment **)ao)[0]; + + sync (output.index); + + unsigned int ii = 0; // input index + + // Are we in sync? + if (!tag_is_seg_sync_or_field_sync (input_tags[0])){ // No ... + + if (d_locked){ + d_locked = false; + d_lost_index = inputs[0].index + ii; + cerr << "GrAtscFieldSyncDemux: lost sync at " + << d_lost_index << endl; + } + + // ... search for beginning of a field sync + + // cerr << "GrAtscFieldSyncDemux: searching for sync at " + // << inputs[0].index + ii << endl; + + for (ii = 1; ii < inputs[0].size; ii++){ + if (atsc::tag_is_start_field_sync (input_tags[ii])){ + // found one + d_locked = true; + + const char *str; + if (atsc::tag_is_start_field_sync_1 (input_tags[ii])) + str = "FIELD-1"; + else if (atsc::tag_is_start_field_sync_2 (input_tags[ii])) + str = "FIELD-2"; + else + str = "SEGMENT"; + + cerr << "GrAtscFieldSyncDemux: synced (" << str << ") at " + << inputs[0].index + ii + << " [delta = " << inputs[0].index + ii - d_lost_index + << "]\n"; + + d_next_input += ii; // update for forecast + return 0; // no work completed so far + } + } + // no non-NORMAL tag found + d_next_input += ii; // update for forecast + return 0; // no work completed so far + } + + // We are in sync. Produce output... + + unsigned int k = 0; // output index + + while (k < output.size){ + + if (inputs[0].size - ii < (unsigned) ATSC_DATA_SEGMENT_LENGTH){ + // We're out of input data. + cerr << "GrAtscFieldSyncDemux: ran out of input data\n"; + d_next_input += ii; // update for forecast + return k; // return amount of work completed so far + } + + if (!tag_is_seg_sync_or_field_sync (input_tags[ii])){ + // lost sync... + // cerr << "GrAtscFieldSyncDemux: lost sync at " + // << inputs[0].index + ii << endl; + + d_next_input += ii; // update for forecast + return k; // return amount of work completed so far + } + + if (atsc::tag_is_start_field_sync_1 (input_tags[ii])){ + d_in_field2 = false; + d_segment_number = 0; + ii += ATSC_DATA_SEGMENT_LENGTH; // skip over field sync + continue; + } + + if (atsc::tag_is_start_field_sync_2 (input_tags[ii])){ + d_in_field2 = true; + d_segment_number = 0; + ii += ATSC_DATA_SEGMENT_LENGTH; // skip over field sync + continue; + } + + if (d_segment_number >= ATSC_DSEGS_PER_FIELD){ + // something's wrong... + cerr << "GrAtscFieldSyncDemux: segment number overflow\n"; + d_segment_number = 0; + } + + out[k].pli.set_regular_seg (d_in_field2, d_segment_number++); + for (int jj = 0; jj < ATSC_DATA_SEGMENT_LENGTH; jj++) + out[k].data[jj] = input_samples[ii + jj]; + ii += ATSC_DATA_SEGMENT_LENGTH; + k++; + } + + d_next_input += ii; // update for forecast + return k; // return amount of work completed +} + |