sink_0::zorder is wrongly treated as a property of "compositor"

[gaoshan2006]

Hi, Could you do me a favor ? I met a problem . I need to use an element of "compositor" in the pipeline. I add this " compositor name=mix sink_0::zorder=2 sink_1::zorder=1 " in the encoder pipeline, I got an error when running gstreamill, which reported "sink_0::zorder is not a property of compositor". It looks the "sink_0::zorder is wrongly treated as a property.

Maybe the way I constructed the pipeline with "compositor" is not correct. If so, how to express this element "compositor name=mix sink_0::zorder=2 sink_1::zorder=1" in pipeline ? Thanks a lot !