+/* Called from main context. If i has an origin sink that uses volume sharing,
+ * then also the origin sink and all streams connected to it need to update
+ * their volume - this function does all that by using recursion. */
+static void update_volume_due_to_moving(pa_sink_input *i, pa_sink *dest) {
+ pa_cvolume new_volume;
+
+ pa_assert(i);
+ pa_assert(dest);
+ pa_assert(i->sink); /* The destination sink should already be set. */
+
+ if (i->origin_sink && (i->origin_sink->flags & PA_SINK_SHARE_VOLUME_WITH_MASTER)) {
+ pa_sink *root_sink = pa_sink_get_master(i->sink);
+ pa_sink_input *origin_sink_input;
+ uint32_t idx;
+
+ if (PA_UNLIKELY(!root_sink))
+ return;
+
+ if (pa_sink_flat_volume_enabled(i->sink)) {
+ /* Ok, so the origin sink uses volume sharing, and flat volume is
+ * enabled. The volume will have to be updated as follows:
+ *
+ * i->volume := i->sink->real_volume
+ * (handled later by pa_sink_set_volume)
+ * i->reference_ratio := i->volume / i->sink->reference_volume
+ * (handled later by pa_sink_set_volume)
+ * i->real_ratio stays unchanged
+ * (streams whose origin sink uses volume sharing should
+ * always have real_ratio of 0 dB)
+ * i->soft_volume stays unchanged
+ * (streams whose origin sink uses volume sharing should
+ * always have volume_factor as soft_volume, so no change
+ * should be needed) */
+
+ pa_assert(pa_cvolume_is_norm(&i->real_ratio));
+ pa_assert(pa_cvolume_equal(&i->soft_volume, &i->volume_factor));
+
+ /* Notifications will be sent by pa_sink_set_volume(). */
+
+ } else {
+ /* Ok, so the origin sink uses volume sharing, and flat volume is
+ * disabled. The volume will have to be updated as follows:
+ *
+ * i->volume := 0 dB
+ * i->reference_ratio := 0 dB
+ * i->real_ratio stays unchanged
+ * (streams whose origin sink uses volume sharing should
+ * always have real_ratio of 0 dB)
+ * i->soft_volume stays unchanged
+ * (streams whose origin sink uses volume sharing should
+ * always have volume_factor as soft_volume, so no change
+ * should be needed) */
+
+ pa_cvolume_reset(&new_volume, i->volume.channels);
+ pa_sink_input_set_volume_direct(i, &new_volume);
+ pa_cvolume_reset(&i->reference_ratio, i->reference_ratio.channels);
+ pa_assert(pa_cvolume_is_norm(&i->real_ratio));
+ pa_assert(pa_cvolume_equal(&i->soft_volume, &i->volume_factor));
+ }
+
+ /* Additionally, the origin sink volume needs updating:
+ *
+ * i->origin_sink->reference_volume := root_sink->reference_volume
+ * i->origin_sink->real_volume := root_sink->real_volume
+ * i->origin_sink->soft_volume stays unchanged
+ * (sinks that use volume sharing should always have
+ * soft_volume of 0 dB) */
+
+ new_volume = root_sink->reference_volume;
+ pa_cvolume_remap(&new_volume, &root_sink->channel_map, &i->origin_sink->channel_map);
+ pa_sink_set_reference_volume_direct(i->origin_sink, &new_volume);
+
+ i->origin_sink->real_volume = root_sink->real_volume;
+ pa_cvolume_remap(&i->origin_sink->real_volume, &root_sink->channel_map, &i->origin_sink->channel_map);
+
+ pa_assert(pa_cvolume_is_norm(&i->origin_sink->soft_volume));
+
+ /* If you wonder whether i->origin_sink->set_volume() should be called
+ * somewhere, that's not the case, because sinks that use volume
+ * sharing shouldn't have any internal volume that set_volume() would
+ * update. If you wonder whether the thread_info variables should be
+ * synced, yes, they should, and it's done by the
+ * PA_SINK_MESSAGE_FINISH_MOVE message handler. */
+
+ /* Recursively update origin sink inputs. */
+ PA_IDXSET_FOREACH(origin_sink_input, i->origin_sink->inputs, idx)
+ update_volume_due_to_moving(origin_sink_input, dest);
+
+ } else {
+ if (pa_sink_flat_volume_enabled(i->sink)) {
+ /* Ok, so this is a regular stream, and flat volume is enabled. The
+ * volume will have to be updated as follows:
+ *
+ * i->volume := i->reference_ratio * i->sink->reference_volume
+ * i->reference_ratio stays unchanged
+ * i->real_ratio := i->volume / i->sink->real_volume
+ * (handled later by pa_sink_set_volume)
+ * i->soft_volume := i->real_ratio * i->volume_factor
+ * (handled later by pa_sink_set_volume) */
+
+ new_volume = i->sink->reference_volume;
+ pa_cvolume_remap(&new_volume, &i->sink->channel_map, &i->channel_map);
+ pa_sw_cvolume_multiply(&new_volume, &new_volume, &i->reference_ratio);
+ pa_sink_input_set_volume_direct(i, &new_volume);
+
+ } else {
+ /* Ok, so this is a regular stream, and flat volume is disabled.
+ * The volume will have to be updated as follows:
+ *
+ * i->volume := i->reference_ratio
+ * i->reference_ratio stays unchanged
+ * i->real_ratio := i->reference_ratio
+ * i->soft_volume := i->real_ratio * i->volume_factor */
+
+ pa_sink_input_set_volume_direct(i, &i->reference_ratio);
+ i->real_ratio = i->reference_ratio;
+ pa_sw_cvolume_multiply(&i->soft_volume, &i->real_ratio, &i->volume_factor);
+ }
+ }
+
+ /* If i->sink == dest, then recursion has finished, and we can finally call
+ * pa_sink_set_volume(), which will do the rest of the updates. */
+ if ((i->sink == dest) && pa_sink_flat_volume_enabled(i->sink))
+ pa_sink_set_volume(i->sink, NULL, false, i->save_volume);
+}
+