-pa_device_port *pa_device_port_new(const char *name, const char *description, size_t extra);
-void pa_device_port_free(pa_device_port *p);
+/* Called from the main thread, from sink-input.c only. The normal way to set
+ * the sink reference volume is to call pa_sink_set_volume(), but the flat
+ * volume logic in sink-input.c needs also a function that doesn't do all the
+ * extra stuff that pa_sink_set_volume() does. This function simply sets
+ * s->reference_volume and fires change notifications. */
+void pa_sink_set_reference_volume_direct(pa_sink *s, const pa_cvolume *volume);