pipewiresrc: no more input formats

Created by: plfiorini

I'm trying to save a stream on disk with GStreamer on Fedora 28 but it doesn't work:

gst-launch-1.0 -v pipewiresrc path=11 ! videoconvert ! queue ! theoraenc ! oggmux ! filesink location="/tmp/out.ogv"
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
ERROR: from element /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0: remote error: no more input formats
Additional debug info:
../src/gst/gstpipewiresrc.c(1013): on_remote_state_changed (): /GstPipeline:pipeline0/GstPipeWireSrc:pipewiresrc0
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...

This pipeline instead works:

gst-launch-1.0 pipewiresrc path=11 ! videoconvert ! ximagesink