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op25-legacy/blocks/src/lib/op25_decoder_ff.cc

231 lines
6.2 KiB
C++

/* -*- C++ -*- */
/*
* Copyright 2008-2011 Steve Glass
*
* This file is part of OP25.
*
* OP25 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.
*
* OP25 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 OP25; 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 <algorithm>
#include <gr_io_signature.h>
#include <iostream>
#include <itpp/comm/bch.h>
#include <logfile_du_handler.h>
#include <offline_imbe_decoder.h>
#include <op25_decoder_ff.h>
#include <snapshot_du_handler.h>
#include <p25cai_du_handler.h>
#include <voice_du_handler.h>
#include <op25_yank.h>
using namespace std;
op25_decoder_ff_sptr
op25_make_decoder_ff()
{
return op25_decoder_ff_sptr(new op25_decoder_ff);
}
op25_decoder_ff::~op25_decoder_ff()
{
}
gr_msg_queue_sptr
op25_decoder_ff::get_msgq() const
{
return d_snapshot_du_handler->get_msgq();
}
void
op25_decoder_ff::set_msgq(gr_msg_queue_sptr msgq)
{
d_snapshot_du_handler->set_msgq(msgq);
}
void
op25_decoder_ff::forecast(int nof_output_items, gr_vector_int &nof_input_items_reqd)
{
/* This block consumes 4800 symbols/s and produces 8000
* samples/s. That's a work rate of 3/5 or 0.6. If no audio output
* is available we'll produce silence.
*/
const size_t nof_inputs = nof_input_items_reqd.size();
const int nof_samples_reqd = .6 * nof_output_items;
fill(&nof_input_items_reqd[0], &nof_input_items_reqd[nof_inputs], nof_samples_reqd);
}
int
op25_decoder_ff::general_work(int nof_output_items, gr_vector_int& nof_input_items, gr_vector_const_void_star& input_items, gr_vector_void_star& output_items)
{
try {
// process input
const float *in = reinterpret_cast<const float*>(input_items[0]);
for(int i = 0; i < nof_input_items[0]; ++i) {
dibit d;
if(in[i] < -2.0) {
d = 3;
} else if(in[i] < 0.0) {
d = 2;
} else if(in[i] < 2.0) {
d = 0;
} else {
d = 1;
}
receive_symbol(d);
}
consume_each(nof_input_items[0]);
// produce audio
audio_samples *samples = d_imbe->audio();
float *out = reinterpret_cast<float*>(output_items[0]);
const int n = min(static_cast<int>(samples->size()), nof_output_items);
if(0 < n) {
copy(samples->begin(), samples->begin() + n, out);
samples->erase(samples->begin(), samples->begin() + n);
}
if(n < nof_output_items) {
fill(out + n, out + nof_output_items, 0.0);
}
return nof_output_items;
} catch(const std::exception& x) {
cerr << x.what() << endl;
exit(1);
} catch(...) {
cerr << "unhandled exception" << endl;
exit(2); }
}
const char*
op25_decoder_ff::destination() const
{
return d_p25cai_du_handler->destination();
}
op25_decoder_ff::op25_decoder_ff() :
gr_block("decoder_ff", gr_make_io_signature(1, 1, sizeof(float)), gr_make_io_signature(0, 1, sizeof(float))),
d_data_unit(),
d_data_unit_handler(),
d_frame_hdr(),
d_imbe(imbe_decoder::make()),
d_state(SYNCHRONIZING),
d_p25cai_du_handler(NULL)
{
d_p25cai_du_handler = new p25cai_du_handler(d_data_unit_handler, "224.0.0.1", 23456);
d_data_unit_handler = data_unit_handler_sptr(d_p25cai_du_handler);
d_snapshot_du_handler = new snapshot_du_handler(d_data_unit_handler);
d_data_unit_handler = data_unit_handler_sptr(d_snapshot_du_handler);
d_data_unit_handler = data_unit_handler_sptr(new voice_du_handler(d_data_unit_handler, d_imbe));
}
bool
op25_decoder_ff::correlated()
{
static const bool FS[] = {
0, 1, 0, 1, 0, 1, 0, 1,
0, 1, 1, 1, 0, 1, 0, 1,
1, 1, 1, 1, 0, 1, 0, 1,
1, 1, 1, 1, 1, 1, 1, 1,
0, 1, 1, 1, 0, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1
};
static const size_t FS_SZ = sizeof(FS)/sizeof(FS[0]);
uint8_t errs = 0;
for(size_t i = 0; i < FS_SZ; ++i) {
if(d_frame_hdr[i] ^ FS[i]) {
++errs;
}
}
return (errs <= 4);
}
data_unit_sptr
op25_decoder_ff::identified()
{
static const size_t NID[] = {
63, 62, 61, 60, 59, 58, 57, 56,
55, 54, 53, 52, 51, 50, 49, 48,
112, 111, 110, 109, 108, 107, 106, 105,
104, 103, 102, 101, 100, 99, 98, 97,
96, 95, 94, 93, 92, 91, 90, 89,
88, 87, 86, 85, 84, 83, 82, 81,
80, 79, 78, 77, 76, 75, 74, 73,
72, 69, 68, 67, 66, 65, 64,
};
size_t NID_SZ = sizeof(NID) / sizeof(NID[0]);
itpp::bvec b(63), zeroes(16);
itpp::BCH bch(63, 16, 11, "6 3 3 1 1 4 1 3 6 7 2 3 5 4 5 3", true);
yank(d_frame_hdr, NID, NID_SZ, b, 0);
b = bch.decode(b);
if(b != zeroes) {
b = bch.encode(b);
yank_back(b, 0, d_frame_hdr, NID, NID_SZ);
d_data_unit = data_unit::make_data_unit(d_frame_hdr);
} else {
data_unit_sptr null;
d_data_unit = null;
}
return d_data_unit;
}
void
op25_decoder_ff::receive_symbol(dibit d)
{
d_frame_hdr.push_back(d & 0x2);
d_frame_hdr.push_back(d & 0x1);
const size_t frame_hdr_sz = d_frame_hdr.size();
switch(d_state) {
case SYNCHRONIZING:
if(48 <= frame_hdr_sz) {
d_frame_hdr.erase(d_frame_hdr.begin(), d_frame_hdr.begin() + (frame_hdr_sz - 48));
if(correlated()) {
d_state = IDENTIFYING;
}
}
break;
case IDENTIFYING:
if(114 == frame_hdr_sz) {
if(identified()) {
d_state = READING;
} else {
d_state = SYNCHRONIZING;
}
}
break;
case READING:
d_data_unit->extend(d);
if(d_data_unit->is_complete()) {
d_data_unit->correct_errors();
d_data_unit_handler->handle(d_data_unit);
data_unit_sptr null;
d_data_unit = null;
d_state = SYNCHRONIZING;
}
break;
}
}