[gentoo-user] off topic: rotating a video

I apologize in advance for this off topic query.

I took a video with my phone (galaxy note 4) and via google+ uploaded it
to my mail laptop.  It is an mp4 and plays fine on both the phone and
the labtop except that it is sideways.

I was surprised that neither the player on the phone nor the player on
the laptop (totem, I run gnome) seems to offer a rotation option.

Am I missing a slightly hidden option or do I need another program.
I do not do video editing and do no plan to in the near future.

thanks,
allan