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sdrangel/plugins/channelrx/demoddatv/ldpctool/encoder.h
2021-03-07 00:36:48 +01:00

70 lines
1.1 KiB
C++

/*
LDPC SISO encoder
Copyright 2018 Ahmet Inan <xdsopl@gmail.com>
*/
#ifndef ENCODER_HH
#define ENCODER_HH
#include "ldpc.h"
namespace ldpctool {
template <typename TYPE>
class LDPCEncoder
{
LDPCInterface *ldpc;
int N, K, R;
bool initialized;
TYPE one()
{
return 1;
}
TYPE sign(TYPE a, TYPE b)
{
return b < TYPE(0) ? -a : b > TYPE(0) ? a : TYPE(0);
}
public:
LDPCEncoder() : initialized(false)
{
}
void init(LDPCInterface *it)
{
if (initialized)
delete ldpc;
initialized = true;
ldpc = it->clone();
N = ldpc->code_len();
K = ldpc->data_len();
R = N - K;
}
void operator()(TYPE *data, TYPE *parity)
{
for (int i = 0; i < R; ++i)
parity[i] = one();
ldpc->first_bit();
for (int j = 0; j < K; ++j) {
int *acc_pos = ldpc->acc_pos();
int bit_deg = ldpc->bit_deg();
for (int n = 0; n < bit_deg; ++n) {
int i = acc_pos[n];
parity[i] = sign(parity[i], data[j]);
}
ldpc->next_bit();
}
for (int i = 1; i < R; ++i)
parity[i] = sign(parity[i], parity[i-1]);
}
~LDPCEncoder()
{
if (initialized)
delete ldpc;
}
};
} // namespace ldpctool
#endif