static int build_def_list(Picture *def, Picture **in, int len, int is_long, int sel) { int i[2] = { 0 }; int index = 0; while (i[0] < len || i[1] < len) { while (i[0] < len && !(in[i[0]] && (in[i[0]]->reference & sel))) i[0]++; while (i[1] < len && !(in[i[1]] && (in[i[1]]->reference & (sel ^ 3)))) i[1]++; if (i[0] < len) { in[i[0]]->pic_id = is_long ? i[0] : in[i[0]]->frame_num; split_field_copy(&def[index++], in[i[0]++], sel, 1); } if (i[1] < len) { in[i[1]]->pic_id = is_long ? i[1] : in[i[1]]->frame_num; split_field_copy(&def[index++], in[i[1]++], sel ^ 3, 0); } } return index; }