Answer by Florian Echtler for How to use GStreamers switchbin element?

The caps in your initial pipelines are not provided by udpsink, they are there so you can tell the downstream elements what kind of data to expect. Therefore, switchbin never sees any of the caps directly and can't choose a pipeline.

I think there's two potential solutions:

1. add a decodebin element right after rtpjitterbuffer which might be able to decode RTP and content together (you'll have to try, not 100% certain)

2. if the streams have different SSRC, you could use rtpssrcdemux to direct the data to the correct pipeline. However, that requires at least a small bit of signal management code and is AFAICT not possible with gst-launch alone.