+ // As long as the mux is plugged, it will not actually write anything to disk,
+ // just queue the packets. Once it is unplugged, the packets are reordered by pts
+ // and written. This is primarily useful if you might have two different encoders
+ // writing to the mux at the same time (because one is shutting down), so that
+ // pts might otherwise come out-of-order.
+ //
+ // You can plug and unplug multiple times; only when the plug count reaches zero,
+ // something will actually happen.
+ void plug();
+ void unplug();
+