Gstreamer: Pipeline is not added and remain nil

问题:

I am working on an iOS app which plays multiple rtsp streams at a time. i have integrated latest Gstreamer binaries and followed demo tutorials from Here

i added a rtsp URL to test my stream , but it is not working.

Gstreamerbackend is not adding pipeline.pipeline is nil. delegate methods are not called

When application runs , it shows message in the logs "Creating pipeline" , but nothing happens. shown in screenshot below.