3D edf writer must inherit from UfoFilterSink

src/ufo-filter-3d-edf-writer.c

@@ -34,7 +34,7 @@ struct _UfoFilter3DEdfWriterPrivate {
 GType ufo_filter_3d_edf_writer_get_type(void) G_GNUC_CONST;
 
 /* Inherit from UFO_TYPE_FILTER */
-G_DEFINE_TYPE(UfoFilter3DEdfWriter, ufo_filter_3d_edf_writer, UFO_TYPE_FILTER);
+G_DEFINE_TYPE(UfoFilter3DEdfWriter, ufo_filter_3d_edf_writer, UFO_TYPE_FILTER_SINK);
 
 #define UFO_FILTER_3D_EDF_WRITER_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE((obj), UFO_TYPE_FILTER_3D_EDF_WRITER, UfoFilter3DEdfWriterPrivate))