+ // If a given device is offline for whatever reason and cannot deliver audio
+ // (by means of add_audio() or add_silence()), you can call put it in silence mode,
+ // where it will be taken to only output silence. Note that when taking it _out_
+ // of silence mode, the resampler will be reset, so that old audio will not
+ // affect it. Same true/false behavior as add_audio().
+ bool silence_card(DeviceSpec device_spec, bool silence);
+