voilà la réponse de gstreamer : alain at alain-laptop:~$ gstreamer-properties gstreamer-properties-Message: Skipping unavailable plugin 'artsdsink' gstreamer-properties-Message: Skipping unavailable plugin 'v4lmjpegsrc' gstreamer-properties-Message: Skipping unavailable plugin 'qcamsrc' gstreamer-properties-Message: Skipping unavailable plugin 'esdmon'