Only support ALSA library
Source:
http://hyperrate.com/volume-osd.tbz
i386 binary executable: volume-osd strip size:9784 bytes
chmod 755 volume-osd
sudo cp volume-osd /usr/bin
~/.config/openbox/lxde-rc.xml
<!-- Keybinding for Volume management -->
<keybind key="XF86AudioRaiseVolume">
<action name="Execute">
<command>volume-osd up</command>
</action>
</keybind>
<keybind key="XF86AudioLowerVolume">
<action name="Execute">
<command>volume-osd down</command>
</action>
</keybind>
<keybind key="XF86AudioMute">
<action name="Execute">
<command>volume-osd mute</command>
</action>
</keybind>