Seems to work fine for me on Zesty. Probably a missing gstreamer plugin. Can you try installing these and then confirming whether it works?
gstreamer1.0-plugins-bad gstreamer1.0-plugins-bad-faad gstreamer1.0-plugins-bad-videoparsers gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-ugly gstreamer1.0-plugins-ugly-amr
Seems to work fine for me on Zesty. Probably a missing gstreamer plugin. Can you try installing these and then confirming whether it works?
gstreamer1. 0-plugins- bad 0-plugins- bad-faad 0-plugins- bad-videoparser s 0-plugins- base 0-plugins- good 0-plugins- ugly 0-plugins- ugly-amr
gstreamer1.
gstreamer1.
gstreamer1.
gstreamer1.
gstreamer1.
gstreamer1.