please exduse me, am'typing on my orbiter keyboard...so will be brief.....
basically, linuxmce can control your av gear.... attach infra red or rs-232 cables to your av gear, and describe the gear to linuxmce, as in how many inputs, how they are connected, etf... andthen you tell linuxmce each command your av devices cqn do, such as how to change volume or channel, for ir this means you'pearn the remote, if we do not already have codes.....
then, you will see your av devices appear in the media menu, and can then select them. If you have connected them to a tuner card, they will initially show through the tuner card, so that the menu can be overlaid over top...you can then select Direct A/V from the menu, to make LinuxMCE switch inputs on your TV and amplifier to show the direct feed.... any button presses on an orbiter or remote that require interaction, will cause LinuxMCE to switch its menu back...
this is automatically available, if you have your hardware set up correctly.
-Thom