You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: get_difference_percentage.m
    path of file: ./repos/audio_steganalysis_ml/feature_extract/feature_analysis
    
    the code of the file until where you have to start completion: %% Get difference percentage (used to select a better preprocessing method)
% difference_percentage(cover_qmdct_file_path, stego_qmdct_file_path)
% - Variable:
% ------------------------------------------input
% cover_qmdct_file_path           path of cover qmdct file
% stego_qmdct_file_path           path of st
    
function difference_percentage(cover_qmdct_file_path, stego_qmdct_file_path)

cover = load(cover_qmdct_file_path);
stego = load(stego_qmdct_file_path);

%% cut
QMDCT_num = 420;
cover = cover(:, 1:QMDCT_num);
stego = stego(:, 1:QMDCT_num);

%% prepcrocessing
% cover
cover_abs = pre_process_matrix(cover, 'abs');

cover_dif_c_1 = pre_process_matrix(cover, 'dif1_h');
cover_dif_r_1 = pre_process_matrix(cover, 'dif1_v');
cover_dif_c_2 = pre_process_matrix(cover, 'dif2_h');
cover_dif_r_2 = pre_process_matrix(cover, 'dif2_v');

cover_abs_dif_c_1 = pre_process_matrix(cover, 'abs_dif1_h');
cover_abs_dif_r_1 = pre_process_matrix(cover, 'abs_dif1_v');
cover_abs_dif_c_2 = pre_process_matrix(cover, 'abs_dif2_h');
cover_abs_dif_r_2 = pre_process_matrix(cover, 'abs_dif2_v');

% stego
stego_abs = pre_process_matrix(stego, 'abs');

stego_dif_c_1 = pre_process_matrix(stego, 'dif1_h');
stego_dif_r_1 = pre_process_matrix(stego, 'dif1_v');
stego_dif_c_2 = pre_process_matrix(stego, 'dif2_h');
stego_dif_r_2 = pre_process_matrix(stego, 'dif2_v');

stego_abs_dif_c_1 = pre_process_matrix(stego, 'abs_dif1_h');
stego_abs_dif_r_1 = pre_process_matrix(stego, 'abs_dif1_v');
stego_abs_dif_c_2 = pre_process_matrix(stego, 'abs_dif2_h');
stego_abs_dif_r_2 = pre_process_matrix(stego, 'abs_dif2_v');

% substraction
diff = cover(:) - stego(:);percentage = length(find(diff ~= 0)) / length(cover(:));
diff_abs = cover_abs(:) - stego_abs(:);percentage_abs = length(find(diff_abs ~= 0)) / length(cover(:));

diff_dif_c_1 = cover_dif_c_1(:) - stego_dif_c_1(:);percentage_dif_c_1 = length(find(diff_dif_c_1 ~= 0)) / length(cover(:));
diff_dif_r_1 = cover_dif_r_1(:) - stego_dif_r_1(:);percentage_dif_r_1 = length(find(diff_dif_r_1 ~= 0)) / length(cover(:));
diff_dif_c_2 = cover_dif_c_2(:) - stego_dif_c_2(:);percentage_dif_c_2 = length(find(diff_dif_c_2 ~= 0)) / length(cover(:));
diff_dif_r_2 = cover_dif_r_2(:) - stego_dif_r_2(:);percentage_dif_r_2 = length(find(diff_dif_r_2 ~= 0)) / length(cover(:));

diff_abs_dif_c_1 = cover_abs_dif_c_1(:) - stego_abs_dif_c_1(:);percentage_abs_dif_c_1 = length(find(diff_abs_dif_c_1 ~= 0)) / length(cover(:));
diff_abs_dif_r_1 = cover_abs_dif_r_1(:) - stego_abs_dif_r_1(:);percentage_abs_dif_r_1 = length(find(diff_abs_dif_r_1 ~= 0)) / length(cover(:));
diff_abs_dif_c_2 = cover_abs_dif_c_2(:) - stego_abs_dif_c_2(:);percentage_abs_dif_c_2 = length(find(diff_abs_dif_c_2 ~= 0)) / length(cover(:));
diff_abs_dif_r_2 = cover_abs_dif_r_2(:) - stego_abs_dif_r_2(:);percentage_abs_dif_r_2 = length(find(diff_abs_dif_r_2 ~= 0)) / length(cover(:));

fprintf('==================================\n');
fprintf('original: %.2f%%\n', percentage*100);
fprintf('absolute: %.2f%%\n', percentage_abs*100);

fprintf('first  order col difference: %.2f%%\n', percentage_dif_c_1*100);
fprintf('first  order row difference: %.2f%%\n', percentage_dif_r_1*100);
fprintf('second order col difference: %.2f%%\n', percentage_dif_c_2*100);
fprintf('second order row difference: %.2f%%\n', percentage_dif_r_2*100);

fprintf('first  order abs col difference: %.2f%%\n', percentage_abs_dif_c_1*100);
fprintf('first  order abs row difference: %.2f%%\n', percentage_abs_dif_r_1*100);
fprintf('second order abs col difference: %.2f%%\n', percentage_abs_dif_c_2*100);
fprintf('second order abs row difference: %.2f%%\n', percentage_abs_dif_r_2*100);
end