Intervideosink/src gives me a black screen

General Discussion
1

Tried the following pipeline on the command line :

gst-launch-1.0 videotestsrc ! videoconvert ! queue ! intervideosink channel=cam_output

gst-launch-1.0 intervideosrc channel=cam_output ! queue ! videoconvert ! autovideosink

I am not getting any error and all I get is a black screen. Used GST_DEBUG=3 and still no error or warnings.

2

It seems they cannot be launched from the command line using gst-launch-1.0.
However this works :
gst-launch-1.0 v4l2src ! videoconvert ! queue ! intervideosink channel=cam_output intervideosrc channel=cam_output ! queue ! videoconvert ! autovideosink