merge_prob
return merge_prob(pre_prob, ct0, ct1, 20, 128);
p[1] = merge_prob(p[1], c[0], c[1] + c[2], count_sat, update_factor);
p[2] = merge_prob(p[2], c[1], c[2], count_sat, update_factor);
p[0] = merge_prob(p[0], c[0], c[1], count_sat, update_factor);