sure what all is supported, it seems http works just fine though.
.
+.SH "WARNING"
+\fIgst\-xmllaunch\fP is deprecated and broken for all but the most simple
+pipelines. It will most likely be removed in future. Don't use it.
+.
.SH "OPTIONS"
.l
\fIgst\-xmllaunch\fP accepts the following options: