portapack-mayhem/firmware/common/bch_code.hpp

/*
 * Copyright (C) 2015 Craig Shelley (craig@microtron.org.uk)
 * Copyright (C) 2016 Furrtek
 *
 * BCH Encoder/Decoder - Adapted from GNURadio
 *
 * This file is part of PortaPack.
 *
 * This program 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 2, or (at your option)
 * any later version.
 *
 * This program 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 this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __BCHCODE_H__
#define __BCHCODE_H__

#include <vector>

class BCHCode {
   public:
    BCHCode(std::vector<int> p_init, int m, int n, int k, int t);
    ~BCHCode();

    BCHCode(const BCHCode&) = delete;
    BCHCode(BCHCode&&) = delete;
    BCHCode& operator=(const BCHCode&) = delete;
    BCHCode& operator=(BCHCode&&) = delete;

    int* encode(int data[]);
    int decode(int recd[]);

   private:
    void gen_poly();
    void generate_gf();

    bool valid{false};

    int d{};
    int* p{};         // coefficients of primitive polynomial used to generate GF(2**5)
    int m{};          // order of the field GF(2**5) = 5
    int n{};          // 2**5 - 1 = 31
    int k{};          // n - deg(g(x)) = 21 = dimension
    int t{};          // 2 = error correcting capability
    int* alpha_to{};  // log table of GF(2**5)
    int* index_of{};  // antilog table of GF(2**5)
    int* g{};         // coefficients of generator polynomial, g(x) [n - k + 1]=[11]
    int* bb{};        // coefficients of redundancy polynomial ( x**(10) i(x) ) modulo g(x)
};

#endif /*__BCHCODE_H__*/