For existing audio hardware there are projects like <a href="http:&#x2F;&#x2F;www.rockbox.org" rel="nofollow">http:&#x2F;&#x2F;www.rockbox.org</a> that are minimalistic firmware replacements that you can hack on. On the video side I can&#x27;t think of anything similar to DVD firmware that&#x27;s open source but that sounds like what you&#x27;re looking for. I&#x27;ve attempted a few slimmed down Linux distros for the Raspberry Pi and alternative OSes that can play back media. Things to check out would be: RISC OS, OpenElec, PiCore, PiPlay, Minibian...