// keep for compatibility with MLT <= 0.8.6
if (af == 0) af = frame->get_int("frequency");
if (ac == 0) ac = frame->get_int("channels");
// keep for compatibility with MLT <= 0.8.6
if (af == 0) af = frame->get_int("frequency");
if (ac == 0) ac = frame->get_int("channels");