video jitter

[James Linder]

G’day

I am (trying out) creating a pipeline to view in 1080

gst-launch-1.0 -v -e  v4l2src name=source device=/dev/video2 ! \
            video/x-h264,width=1920,height=1080,framerate=30/1 ! \
            h264parse ! avdec_h264 ! \
            xvimagesink

I have tried a queue throught the chain without seeing any change.
htop shows 4 cores at 30ish %.

using mplayer directly on the source shows 4 cores at 60ish % with absolutely smooth playback.
-v says nothing that grabs attention.

Can anybody say ah-ha do this-or-that?
Thanks
James