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scramble user data only using Xorshift32

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Ahmet Inan 2021-07-18 04:48:32 +02:00
commit ef152cc53f
2 changed files with 13 additions and 15 deletions
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15
encode.cc
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@ -7,6 +7,7 @@ Copyright 2021 Ahmet Inan <inan@aicodix.de>
#include <iostream>
#include <cassert>
#include <cmath>
#include "xorshift.hh"
#include "complex.hh"
#include "utils.hh"
#include "bitman.hh"
@ -35,8 +36,6 @@ struct Encoder
static const int mls1_len = 255;
static const int mls1_poly = 0b100101011;
static const int mls2_poly = 0b100101010001;
static const int mls3_poly = 0b10001000000001011;
static const int mls4_poly = 0b10111010010000001;
DSP::WritePCM<value> *pcm;
DSP::FastFourierTransform<symbol_len, cmplx, 1> bwd;
DSP::FastFourierTransform<4*symbol_len, cmplx, -1> fwd4;
@ -239,13 +238,10 @@ struct Encoder
code[i] = nrz(CODE::get_le_bit(inp, i));
ldpcenc(code, code + bch_bits);
interleave();
CODE::MLS seq3(mls3_poly), seq4(mls4_poly);
for (int j = 0; j < code_rows; ++j) {
for (int i = 0; i < code_cols; ++i) {
cmplx con = mod_map(bint+mod_bits*(code_cols*j+i));
con = cmplx(con.real() * nrz(seq3()), con.imag() * nrz(seq4()));
fdom[bin(i+code_off)] *= con;
}
for (int i = 0; i < code_cols; ++i)
fdom[bin(i+code_off)] *=
mod_map(bint+mod_bits*(code_cols*j+i));
symbol();
}
schmidl_cox();
@ -345,6 +341,9 @@ int main(int argc, char **argv)
uint8_t *input_data = new uint8_t[code_len];
for (int i = 0; i < data_len; ++i)
input_data[i] = input_file.get();
CODE::Xorshift32 scrambler;
for (int i = 0; i < data_len; ++i)
input_data[i] ^= scrambler();
DSP::WriteWAV<value> output_file(output_name, output_rate, output_bits, output_chan);
output_file.silence(output_rate);