[LAU] Audio mixer using a raspberry-pi and some external audio card

Hi, I don't know if what I'm going to ask makes sense or is terribly stupid. Don't be too harsh on me if it's the latter, please :-) I've got two audio "outputs" (headphones and a 4.1 set of speakers) and two audio "inputs" (a computer and a TV). In an ideal world, I'd be able to switch between them with some sort of device: let's say I'm watching a film through the speakers but it's getting late and I want to switch to the headphones. Or I'm done with the TV and I want to do something with the computer, and want to listen to that instead. I don't know what kind of devices are used in the real world to do this, but to me it looks quite similar to what we do with Jack. So I thought that with some small Linux-capable device (hence the Raspberry-pi) and some external audio card (with two inputs and two outputs; or maybe even two different external cards, each one with one input and output), you should be able to build a DYI audio mixer for not-so-much money. You could ssh into it and use qjackctl or the like to adjust inputs and outputs. Am I completely off-mark, or is this a viable/common/established thing? Thanks in advance, -- Roberto Suarez Soto Hurt me plenty