By default, while playing a video in XBMC, the mouse wheel scroll function controls forward and rewind. However, controling volume with the mouse wheel would be more practical.
In case you don’t already have it, XBMC is a great and open source media center that has a lot of great features.
To change the mouse wheel function, you need to edit an XML file; and to do this, run the following command:
sudo gedit ‘/usr/share/xbmc/system/keymaps/mouse.xml’
Then add the following code before </keymap> and after <keymap>
That’s it! scrolling up or down must now change the volume.