i think this fixes a memory leak

src/playbin.vala

@@ -12,6 +12,7 @@ private class SourceFuncWrapper {
     }
 }
 
+
 class Playbin : GLib.Object {
     private Mpv.Handle mpv = new Mpv.Handle ();
 

src/vapi/mpv.vapi

@@ -121,7 +121,7 @@ namespace Mpv {
 
     [CCode (cname = "mpv_event_property", destroy_function = "", has_type_id = false, has_copy_function = false)]
     public struct EventProperty {
-        string name;
+        unowned string name;
         Format format;
         void *data;