We reported over the weekend that there was some confusion over exactly how Apple’s new Lightning digital AV adapter works and why it lacks the ability to carry a native 1080p signal. One theory is that Apple was using an AirPlay wireless streaming protocol, but we’ve since learned that is not the case. According to a post that purports to be from an anonymous Apple engineer explaining how the cables function, Apple does not use Airplay protocol. It instead uses the same H.264 encoding technology as AirPlay to encode the output into the ARM SoC. From there, the data is decoded and sent over HDMI:
It’s vastly the same thing with the HDMI adapter. Lightning doesn’t have anything to do with HDMI at all. Again, it’s just a high speed serial interface. Airplay uses a bunch of hardware h264 encoding technology that we’ve already got access to, so what happens here is that we use the same hardware to encode an output stream on the fly and fire it down the Lightning cable straight into the ARM SoC the guys at Panic discovered. Airplay itself (the network protocol) is NOT involved in this process. The encoded data is transferred as packetized data across the Lightning bus, where it is decoded by the ARM SoC and pushed out over HDMI.
Perhaps even more interesting is that Apple could improve the quality with future software updates since the firmware is stored in RAM as opposed to ROM. The poster noted that Apple deemed the quality “suitably acceptable” but *will* make improvements with future iOS updates:
Certain people are aware that the quality could be better and others are working on it. For the time being, the quality was deemed to be suitably acceptable. Given the dynamic nature of the system (and the fact that the firmware is stored in RAM rather then ROM), updates **will** be made available as a part of future iOS updates. When this will happen I can’t say for anonymous reasons, but these concerns haven’t gone unnoticed.
The anonymous poster explained the reason behind the technology is to allow us “to output to any device on the planet, irregardless of the endpoint bus”:
This system essentially allows us to output to any device on the planet, irregardless of the endpoint bus (HDMI, DisplayPort, and any future inventions) by simply producing the relevant adapter that plugs into the Lightning port. Since the iOS device doesn’t care about the hardware hanging off the other end, you don’t need a new iPad or iPhone when a new A/V connector hits the market.
The post doesn’t offer a timeframe for when we might see upgrades through a software update, but it did claim that people are now aware of the issues and working on making improvements.