X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=gr-atsc%2Fsrc%2Flib%2FGrAtscFieldSyncMux.cc;fp=gr-atsc%2Fsrc%2Flib%2FGrAtscFieldSyncMux.cc;h=8df36ba4baffbef5ee17eb8617967403b14a22b1;hb=35e43e8d8c271e6842191cac3fc3f2f88a861183;hp=0000000000000000000000000000000000000000;hpb=ea29b08aeb54227e6628f655ccfdb96fe4d8c378;p=debian%2Fgnuradio diff --git a/gr-atsc/src/lib/GrAtscFieldSyncMux.cc b/gr-atsc/src/lib/GrAtscFieldSyncMux.cc new file mode 100644 index 00000000..8df36ba4 --- /dev/null +++ b/gr-atsc/src/lib/GrAtscFieldSyncMux.cc @@ -0,0 +1,246 @@ +/* -*- 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 +#include + + +// typedefs for fundamental i/o types + +typedef atsc_data_segment iType; +typedef atsc_data_segment oType; + +static const int NUMBER_OF_OUTPUTS = 1; // # of output streams (almost always one) + +static const int N_SAVED_SYMBOLS = GrAtscFieldSyncMux::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); +} + + +GrAtscFieldSyncMux::GrAtscFieldSyncMux () + : VrHistoryProc (NUMBER_OF_OUTPUTS), + d_current_index (0), d_already_output_field_sync (false) +{ + // 1 + number of extra input elements at which we look. This is + // used by the superclass's forecast routine to get us the correct + // range on our inputs. + history = 1; + + // any other init here. +} + +GrAtscFieldSyncMux::~GrAtscFieldSyncMux () +{ + // Anything that isn't automatically cleaned up... +} + +void +GrAtscFieldSyncMux::pre_initialize () +{ + // we jack our output sampling frequency up to account for inserted field syncs + setSamplingFrequency (getInputSamplingFrequencyN (0) * 313./312.); +} + +/* + * we need a non-standard version of forecast because our output isn't + * exactly 1:1 with our input. + */ + +int +GrAtscFieldSyncMux::forecast (VrSampleRange output, VrSampleRange inputs[]) +{ + for(unsigned int i = 0; i < numberInputs; i++) { + inputs[i].index = d_current_index; + inputs[i].size = output.size; + } + return 0; +} + +/* + * This is the real work horse. In general this interface can handle + * multiple streams of input and output, but we almost always + * use a single input and output stream. + */ +int +GrAtscFieldSyncMux::work (VrSampleRange output, void *ao[], + VrSampleRange inputs[], void *ai[]) +{ + // If we have state that persists across invocations (e.g., we have + // instance variables that we modify), we must use the sync method + // to indicate to the scheduler that our output must be computed in + // order. This doesn't keep other things from being run in + // parallel, it just means that at any given time, there is only a + // single thread working this code, and that the scheduler will + // ensure that we are asked to produce output that is contiguous and + // that will be presented to us in order of increasing time. + + // We have state, hence we must use sync. + + sync (output.index); + + // construct some nicer i/o pointers to work with. + + iType *in = ((iType **) ai)[0]; + oType *out = ((oType **) ao)[0]; + + + // We must produce output.size units of output. + + unsigned int index = 0; + for (unsigned int outdex = 0; outdex < output.size; 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 the number of units we produced. + // Note that for all intents and purposes, it is an error to + // produce less than you are asked for. + + return output.size; +}