GST_VALUE_LCOPY  2560 gst/gststructure.c     GST_VALUE_LCOPY (val, args, 0, &err, field_name);
GST_VALUE_LCOPY  2629 gst/gststructure.c     GST_VALUE_LCOPY (val, args, 0, &err, g_quark_to_string (field_id));