The Restore Stream modules monitors pw_node of media class "Stream/..." and "Audio/..." and saves the SPA_PROP_volume, SPA_PROP_mute, and SPA_PROP_channelMap parameters to the route-settings state file and the route-settings metadata objects.

When a stream re-appears and matches a saved state, the parameters are restored to their respective values. Additionally, the target node is saved so the stream can be re-associated with that node, if possible.

To match a stream with a previously saved state, this module uses one of PW_KEY_MEDIA_ROLE, PW_KEY_APP_ID, PW_KEY_APP_NAME, PW_KEY_MEDIA_NAME, and PW_KEY_NODE_NAME, whichever applies.

The state file is $XDG_STATE_HOME/pipewire/media-session.d/restore-stream.

The route-settings metadata object is owned by this module.