The fine folks at Panic were experimenting with video out from iOS -- never we mind why -- and came across an interesting discovery: Apple's Lightning Digital AV adapter, aka HDMI adapter, doesn't seem to pass along a 1080p signal in the traditional manner. Instead, it looks like it's passing along upscaled AirPlay-like video. Intrigued as to how, Cabel Sasser gutted the adapter like a Tauntaun on a cold night to find out, and shared what he discovered on the Panic Blog:
Your eyes don’t deceive you — that tiny chip says ARM. And the H9TKNNN2GD part number on there points towards RAM — 2Gb worth.
So it's a tiny computer. More specifically, a tiny, single purpose, hard-lined Apple TV-esque device. That explains the less-than-stellar quality of the output (ugh!), but not why Apple chose to go this way.
For some theories on that, and more on Panic's adapter adventure, including the torn-open guts of the gear, check out the link below.
Source: Panic Blog