> Feels like the box should have a bunch of buffers or tuners or whatever the necessary technology is and guess what channel I might flip to next (up, down, pre

> Feels like the box should have a bunch of buffers or tuners or whatever the necessary technology is and guess what channel I might flip to next (up, down, previous would be good starts). It could have those streams ready to go in a millisecond. I'm not an codec expert but, AFAIK, apart from buffering you also need to decode since the latest keyframe (so, typically, last n seconds of input).