satdump/src-core/utils/majority_law.cpp

#include "logger.h"
#include <vector>

/**
 * @brief Applies majority law between input elements on a bit level, returns a vector of the corrected value
 *
 * @param input A vector of vectors of bytes to apply majority law between. ALL ELEMENT VECTORS SHOULD BE THE SAME SIZE!!!
 * @return std::vector<unsigned char>
 */
std::vector<unsigned char> majority_law_vec(std::vector<std::vector<unsigned char>> input)
{
    std::vector<unsigned char> output;
    int zero_votes = 0;
    int one_votes = 0;
    int stop_byte_count = input[0].size();
    ;

    if (stop_byte_count == 0)
    {
        logger->error("Majority law was attempted with an empty vector!");
        return output;
    }

    for (int cur_byte_position = 0; cur_byte_position != stop_byte_count; cur_byte_position++)
    {
        unsigned char output_byte = 0;

        for (int bit = 7; bit >= 0; bit--)
        {
            // Gets the bit value from each element
            for (int element = 0; element < input.size(); element++)
            {
                unsigned char byte = input[element][cur_byte_position];

                if (((byte >> bit) & 1) == 0)
                {
                    zero_votes++;
                }
                else
                {
                    one_votes++;
                }
            }

            // Push new bit
            output_byte = output_byte << 1;

            if (one_votes >= zero_votes)
            {
                // If it is meant to be one, set it to one
                output_byte |= 1;
            }

            // Reset the votes for the next bit
            one_votes = 0;
            zero_votes = 0;
        }
        // Add to output
        output.push_back(output_byte);
    }
    return output;
}