habdec/code/Decoder/RTTY.h

141 wiersze
2.7 KiB
C++

/*
Copyright 2018 Michal Fratczak
This file is part of habdec.
habdec 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 of the License, or
(at your option) any later version.
habdec 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 habdec. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
#include "stddef.h"
#include <vector>
#include <iostream>
#include <cctype>
#include "common/console_colors.h"
namespace habdec
{
template<typename TBit>
class RTTY
{
public:
void ascii_bits(size_t i_bits) {nbits_ = i_bits;};
size_t ascii_bits() const {return nbits_;};
void ascii_stops(float i_stops) {nstops_ = i_stops;};
float ascii_stops() const {return nstops_;};
void push(const std::vector<TBit>& i_bits);
size_t size() {return chars_.size();}
std::vector<char> get();
size_t operator()();
private:
size_t nbits_ = 0;
float nstops_ = 0;
std::vector<TBit> bits_;
std::vector<char> chars_;
};
template<typename TBit>
void RTTY<TBit>::push(const std::vector<TBit>& i_bits)
{
using namespace std;
bits_.insert( bits_.end(), i_bits.begin(), i_bits.end() );
}
template<typename TBit>
std::vector<char> RTTY<TBit>::get()
{
auto res = chars_;
chars_.clear();
return res;
}
template<typename TBit>
size_t RTTY<TBit>::operator()()
{
if(!nbits_ && !nstops_)
return 0;
if( bits_.size() < (1+nbits_+nstops_) )
return 0;
using namespace std;
size_t n_decoded_chars = 0;
size_t last_decoded_bit_index = 0;
for(size_t i=0; i<bits_.size()/*-char_bitlen*/; /**/)
{
bool is_char_seq =
bits_[i] == 0; // start bit?
// at least 1+8+2 bits available ?
is_char_seq &= (i + 1+nbits_+nstops_) <= bits_.size();
// has stop bits ?
for(size_t s=0; s<nstops_; ++s)
is_char_seq &= bits_[i+1+nbits_ + s] == 1;
if( !is_char_seq )
{
++i;
continue;
}
// this has to be char sequence
{
++i;
// bit to char
char c = 0;
for(size_t _c=0; _c<nbits_; ++_c)
{
c += bits_[i] << _c;
++i;
}
// if( isprint(c) || c == '\n' )
{
chars_.push_back(c);
++n_decoded_chars;
}
i += nstops_;
last_decoded_bit_index = i-1; // points to last stop bit
}
}
if(last_decoded_bit_index)
bits_.erase( bits_.begin(), bits_.begin() + last_decoded_bit_index + 1 );
return n_decoded_chars;
}
} // namespace habdec