volumewheel lets you to use the mouse wheel to control the volume level in Totem (>= 3.12)
Install the dependencies:
sudo apt-get install gir1.2-clutter-1.0 gir1.2-gtkclutter-1.0 gir1.2-gtk-3.0 gir1.2-peas-1.0 gir1.2-pango-1.0
Download this repository and move the volumewheel directory to:
~/.local/share/totem/plugins/
and then you can enable it in Totem → Preferences → Plugins → Volume Wheel
