Playing around with gstreamer fails strangely

[Paolo Bolzoni]

Dear list,

Here is my first tries:

# modprobe --first-time v4l2loopback devices=2 exclusive_caps=0
# gst-launch-1.0 videotestsrc !  videoconvert   ! v4l2sink device=/dev/video1

However this fails (see the error lines in the bottom) and I quite
confused because I am sure
in the past I was able to make it work.

I used gst-inspect-1.0 to verify that all caps are fine and everything
seems correct. What can i try?

Cheers,
Paolo



Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
ERROR: from element
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data
stream error.
Additional debug info:
gstbasesrc.c(3055): gst_base_src_loop ():
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0:
streaming stopped, reason not-negotiated (-4)
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...