-int pa_source_suspend(pa_source *s, pa_bool_t suspend, pa_suspend_cause_t cause);
-int pa_source_suspend_all(pa_core *c, pa_bool_t suspend, pa_suspend_cause_t cause);
+int pa_source_suspend(pa_source *s, bool suspend, pa_suspend_cause_t cause);
+int pa_source_suspend_all(pa_core *c, bool suspend, pa_suspend_cause_t cause);
+
+/* Use this instead of checking s->flags & PA_SOURCE_FLAT_VOLUME directly. */
+bool pa_source_flat_volume_enabled(pa_source *s);
+
+/* Get the master source when sharing volumes */
+pa_source *pa_source_get_master(pa_source *s);
+
+/* Is the source in passthrough mode? (that is, is this a monitor source for a sink
+ * that has a passthrough sink input connected to it. */
+bool pa_source_is_passthrough(pa_source *s);
+/* These should be called when a source enters/leaves passthrough mode */
+void pa_source_enter_passthrough(pa_source *s);
+void pa_source_leave_passthrough(pa_source *s);
+
+void pa_source_set_volume(pa_source *source, const pa_cvolume *volume, bool sendmsg, bool save);
+const pa_cvolume *pa_source_get_volume(pa_source *source, bool force_refresh);