Identify keys

Open a console
Run xev (xbase-clients)

Search "keycode". In this example, it's 160

KeyPress event, serial 28, synthetic NO, window 0x2800001,
    root 0x5c, subw 0x0, time 3864774064, (-249,385), root:(429,410),
    state 0x0, keycode 160 (keysym 0x0, NoSymbol), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

Try and note down all multimedia keys.

Key naming

Here, we're going to use xmodmap to modify keymaps and insert our multimedia keys.

Create a new text file: ~/.xmodmaprc
The file uses this syntax:

keycode YOUR_KEYCODE = YOUR_NAME

Choose a name in /usr/share/X11/XKeysymDB. Note that xmodmap manual refer to /usr/lib/X11/XKeysymDB, but it's wrong on my Debian Etch open a bug ?

For example:

keycode 160 = XF86AudioMute
keycode 174 = XF86AudioLowerVolume
keycode 176 = XF86AudioRaiseVolume
keycode 162 = XF86AudioPlay
keycode 144 = XF86AudioPrev
keycode 145 = XF86AudioNext
keycode 164 = XF86AudioStop
keycode 237 = XF86HomePage

To apply that, run:

xmodmap ~/.xmodmaprc

Autostart for KDE

To load your change at startup, create a ~/.kde/Autostart/xmodmap.sh file with the following contents:

xmodmap ~/.xmodmaprc

This file must be executable:

chmod +x ~/.kde/Autostart/xmodmap.sh

Assign an action on your keys

Under KDE

Global shortcut (Recommended)

In all applications supporting DCOP calls (KDE compatible), you can assign your multimedia keys as shortcuts. It's a very powerful and very simple feature!

Example with Kmix:

Open K > Multimedia > Kmix sound mixer
Show Mixer Window
Go to Setting > Configure Global Shortcuts...

attachment:example-kde-kmix.png

This works fine with ["Amarok"] too.

Input Action

This method is more generic.

Go to

K > Configuration > Regional & Accessibility > Input Action

Create new group called "Multimedia"
Create new action

KHotKey Daemon

Not tested

Under Gnome