[Dan] wrote in to share a link to his MythTv to Apple TV setup. He found a way to make the recordings he made on his Linux box available on the 2nd Generation Apple TV. Our first thought is that he would use XBMC on a jailbroken device but that is not the case. The secret is to roll iTunes into the mix.
Take a look at the diagram above. The system starts with an Arch Linux box that runs MythTV, an open source program which allows you to record from tuner or encoder hardware. But actually watching those recordings on an iOS device is difficult for a couple of reasons. First, Apple likes to keep their devices locked up tight in hopes that you buy your entertainment rather than watching over-the-air records. Second, if you’re recording ATSC channels the files may be 1080i or 1080p, neither of which can be handled by the Apple TV 2. [Dan] gets around this by first using the command line version of Handbrake to transcode the recordings to an h264 format. He then uses iTunes running on an Windows 7 virtual machine (on the Linux box) to host the transcoded files in a library the Apple TV can access.