diff options
Diffstat (limited to 'gr-atsc/src/lib/atsci_equalizer.cc')
| -rw-r--r-- | gr-atsc/src/lib/atsci_equalizer.cc | 248 |
1 files changed, 0 insertions, 248 deletions
diff --git a/gr-atsc/src/lib/atsci_equalizer.cc b/gr-atsc/src/lib/atsci_equalizer.cc deleted file mode 100644 index 4aec47495..000000000 --- a/gr-atsc/src/lib/atsci_equalizer.cc +++ /dev/null @@ -1,248 +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_equalizer.h> -#include <algorithm> -#include <iostream> -#include <atsc_types.h> - -using std::cerr; -using std::endl; -using std::min; - - -// total number of symbols (including field sync) / field -static const int SYMBOLS_PER_FIELD = - (ATSC_DSEGS_PER_FIELD + 1) * ATSC_DATA_SEGMENT_LENGTH; - - -atsci_equalizer::atsci_equalizer () -{ - d_locked_p = false; - d_offset_from_last_field_sync = 0; - d_current_field = 0; -} - -atsci_equalizer::~atsci_equalizer () -{ -} - -void -atsci_equalizer::reset () -{ - d_locked_p = false; - d_offset_from_last_field_sync = 0; - d_current_field = 0; -} - -/* - * Errrr.... Define to 1 if compiler handles tail recursion without pushing - * unnecessary stack frames, else define to 0 for lame compilers. - */ -#define WINNING_COMPILER 0 - - -/* - * divide and conquer... - * - * Note that this could be refactored to take advantage of the - * symbol_num that is contained in the input_tags. Then we wouldn't - * have to be counting here. - * - * Today's strategy: get it working. - */ - -void -atsci_equalizer::filter (const float *input_samples, - const atsc::syminfo *input_tags, - float *output_samples, - int nsamples) -{ - lame_compiler_kludge: - - if (!d_locked_p){ - - // look for a field sync - - int i; - for (i = 0; i < nsamples; i++){ - if (atsc::tag_is_start_field_sync (input_tags[i])) - break; - } - - // whether we found one or not, everything up to it should - // be run through the normal path - - if (i != 0) - filter_normal (input_samples, output_samples, i); - - if (i == nsamples) // no field sync found, still not locked. - return; - - // OK, we've just transitioned to the locked state. - - d_locked_p = true; - d_offset_from_last_field_sync = 0; - - // handle locked case recursively - - if (WINNING_COMPILER) - filter (&input_samples[i], &input_tags[i], - &output_samples[i], nsamples - i); - else { - input_samples += i; - input_tags += i; - output_samples += i; - nsamples -= i; - goto lame_compiler_kludge; - } - - return; - } - - // We're in the locked state. - // - // Figure out where we are with respect to a data segment boundary - // and do the right thing. Note that in the interested of performance, - // we don't scan all the tags looking for trouble. We only check - // them where we expect them to be non-NORMAL. Worst case, it'll take - // us a field to notice that something went wrong... - - if (d_offset_from_last_field_sync % SYMBOLS_PER_FIELD == 0){ // we should be looking - // at a field sync - if (atsc::tag_is_start_field_sync_1 (input_tags[0])) - d_current_field = 0; - - else if (atsc::tag_is_start_field_sync_2 (input_tags[0])) - d_current_field = 1; - - else { // we're lost... no field sync where we expected it - - cerr << "!!! atsci_equalizer: expected field sync, didn't find one\n"; - - d_locked_p = false; - d_offset_from_last_field_sync = 0; - - if (WINNING_COMPILER) - filter (input_samples, input_tags, output_samples, nsamples); - else - goto lame_compiler_kludge; - - return; - } - - // OK, everything's cool. We're looking at a field sync. - - int n = min (ATSC_DATA_SEGMENT_LENGTH, nsamples); - - filter_field_sync (input_samples, output_samples, n, 0, d_current_field); - - d_offset_from_last_field_sync = n; - nsamples -= n; - - if (nsamples > 0){ - if (WINNING_COMPILER) - filter (&input_samples[n], &input_tags[n], - &output_samples[n], nsamples); - else { - input_samples += n; - input_tags += n; - output_samples += n; - goto lame_compiler_kludge; - } - } - return; - } - - if (d_offset_from_last_field_sync < ATSC_DATA_SEGMENT_LENGTH){ // we're in the middle of a field sync - int n = min (ATSC_DATA_SEGMENT_LENGTH - d_offset_from_last_field_sync, nsamples); - - filter_field_sync (input_samples, output_samples, n, - d_offset_from_last_field_sync, d_current_field); - - d_offset_from_last_field_sync += n; - nsamples -= n; - - if (nsamples > 0){ - if (WINNING_COMPILER) - filter (&input_samples[n], &input_tags[n], - &output_samples[n], nsamples); - else { - input_samples += n; - input_tags += n; - output_samples += n; - goto lame_compiler_kludge; - } - } - return; - } - - // OK, we're not in a field sync. We're either in a data segment sync or in the clear... - - int seg_offset = d_offset_from_last_field_sync % ATSC_DATA_SEGMENT_LENGTH; - - assert (seg_offset >= 0); - - if (seg_offset < 4){ // somewhere in a data seg sync. - int n = min (4 - seg_offset, nsamples); - - filter_data_seg_sync (input_samples, output_samples, n, seg_offset); - - d_offset_from_last_field_sync += n; - nsamples -= n; - - if (nsamples > 0){ - if (WINNING_COMPILER) - filter (&input_samples[n], &input_tags[n], - &output_samples[n], nsamples); - else { - input_samples += n; - input_tags += n; - output_samples += n; - goto lame_compiler_kludge; - } - } - return; - } - - // otherwise... we're in the normal zone - - int n = min (ATSC_DATA_SEGMENT_LENGTH - seg_offset, nsamples); - - filter_normal (input_samples, output_samples, n); - - d_offset_from_last_field_sync += n; - nsamples -= n; - - if (nsamples <= 0) - return; - - if (WINNING_COMPILER) - filter (&input_samples[n], &input_tags[n], - &output_samples[n], nsamples); - else { - input_samples += n; - input_tags += n; - output_samples += n; - goto lame_compiler_kludge; - } -} |