get_ctrl_ptr
if (p->value == *get_ctrl_ptr(minfo, i)) return 0;
*get_ctrl_ptr(minfo, i) = p->value;
p->value = *get_ctrl_ptr(minfo, i);
*get_ctrl_ptr(minfo, i) = g450_controls[i].desc.default_value;
if (p->value == *get_ctrl_ptr(md, i)) return 0;
*get_ctrl_ptr(md, i) = p->value;
p->value = *get_ctrl_ptr(md, i);
*get_ctrl_ptr(md, i) = maven_controls[i].desc.default_value;