ARM chip found in Apple's Lightning Digital AV Adapter could be AirPlay decoder
A recent teardown of Apple's Digital AV Adapter for Lightning connectors reveals that the unit comes with an embedded ARM system on a chip, complete with 256MB of RAM, which some speculate acts as an AirPlay decoder.
The discovery was made by developers at Panic Software, who stumbled upon the ARM chip in troubleshooting the device for video-out capabilities in an upcoming project.
As Apple describes it, the Lightning AV Adapter "mirrors exactly what you see on your device so that everyone in the room can enjoy it on your widescreen TV, video projection screen, or other HDMI-compatible display." It also supports 1080p output from an iPhone 5, fifth-gen iPod touch, fourth-gen iPad or iPad mini. As seen above, the unit sport a Lightning connector and an HDMI output.
Source: Panic Software
It is unclear why the accessory would require such advanced hardware, but Panic believes the adapter is outputting video by using Apple's AirPlay protocol. The firm was led to the conclusion after noting image artifacts and limited resolution suspiciously akin to those found when an iOS device streams to an Apple TV.
The discovery was made by developers at Panic Software, who stumbled upon the ARM chip in troubleshooting the device for video-out capabilities in an upcoming project.
As Apple describes it, the Lightning AV Adapter "mirrors exactly what you see on your device so that everyone in the room can enjoy it on your widescreen TV, video projection screen, or other HDMI-compatible display." It also supports 1080p output from an iPhone 5, fifth-gen iPod touch, fourth-gen iPad or iPad mini. As seen above, the unit sport a Lightning connector and an HDMI output.
Source: Panic Software
It is unclear why the accessory would require such advanced hardware, but Panic believes the adapter is outputting video by using Apple's AirPlay protocol. The firm was led to the conclusion after noting image artifacts and limited resolution suspiciously akin to those found when an iOS device streams to an Apple TV.
Initial testing of the adapter also found that Lightning may not be able to support full 1080p resolution over HDMI, lending credence to the theory that the device is actually converting the output signal into an upscaled AirPlay stream.All we can figure is that the small number of Lightning pins prevented them from doing raw HDMI period, and the elegance of the adapter trumped the need for traditional video out, so someone had to think seriously out of the box. Or maybe they want get as much functionality out of the iPad as possible to reduce cost and complexity.
Comments
Originally Posted by AppleInsider
…the unit comes with an embedded ARM system on a chip, complete with 256MB of RAM, which some speculate acts as an AirPlay decoder.
Nope. It's for running iOS.
This adapter has as much RAM as the first iPhone. I don't see why not.
It is unclear why the accessory would require such advanced hardware
"Obviously for the sole purpose of making the accessory overpriced!"
Quote:
Originally Posted by AppleInsider
Initial testing of the adapter also found that Lightning may not be able to support full 1080p resolution over HDMI, lending credence to the theory that the device is actually converting the output signal into an upscaled AirPlay stream.
Well there is a bit of a difference when Lightning has 9 pins and HDMI has 19.
Upscaling bad.
Why would they load iOS on an adapter?
Originally Posted by SolipsismX
Why would they load iOS on an adapter?
Crap, ¡.
Hm, while I certainly do not know, I consider most of the explanations too complicated. An easier approach would be to multiplex the source signal to reduce the amount of pins required, and then inverse multiplex it in the adapter. The chip and RAM could simply handle inverse multiplexing and buffering. Upscaling is not the only possible cause of artifacts, it could simply be syncing issues in the demuxing.
Originally Posted by bdkennedy1
So are we saying that this thing is over-engineered because Apple needed to make a new connector in order to save space in it's iPhone and iPad?
I don't think so.
Quote:
Originally Posted by SolipsismX
Quote:
Originally Posted by Tallest Skil
Nope. It's for running iOS.
This adapter has as much RAM as the first iPhone. I don't see why not.
As much RAM as the Model A Raspberry Pi. I wonder if people will load Linux on it just to do it.
Why would they load iOS on an adapter?
They may not be running iOS, but they are some kind of OS. Perhaps the iPod Nano OS?
Quote:
Originally Posted by Tallest Skil
Quote:
Originally Posted by bdkennedy1
So are we saying that this thing is over-engineered because Apple needed to make a new connector in order to save space in it's iPhone and iPad?
I don't think so.
I don't think it's a completely unreasonable premise, particularly on the emaciated iPhone5 and iPodT.
I wouldn't call it over-engineered since it presumably won't function properly without these additions.
You could argue that iDevices or the Lightning connector are over-engineered but then you'd have account for this adapter being uncommon and that including the cost in each iDevice and making the iDevice more complex and costly when it's the item sold in huge quantities, and that Apple should have not included a future-forward connector to replace its aging decade old iPod Dock Connector, but I don't think that would be a good position to take.
If you want a recent example of over-engineering I think the new iMac qualifies on every level. We're moving on 6 month since they were announced and it's still weeks of waiting and it doesn't appear to be from a higher than expected demand.
Neither does coax but neither of those options can do what Apple's Lightning connector can do.
Quote:
Originally Posted by SolipsismX
Neither does coax but neither of those options can do what Apple's Lightning connector can do.
Such as?
If I understand correctly, this adapter hast to perform several tasks:
1. Since Lightning is basically a software defined interface, the adapter has to identify itself and tell the "mother device" to configure Lightning for video output
2. The adapter must negotiate the desired resolution of the output signal with the attached HDMI device.
3.The adapter has to establish a digital data transmission link with the ARM chip in the "mother device" and receive display data at the native resolution of that device in real time
4. It must convert every image from the format and resolution received via Lightning to the proper HDMI output format and resolution.
It seems perfectly reasonable to me that Apple would use an ARM SoC for this, since ARM is what the software guys are familiar with, and it allows them to minimize the chip count.
Mini-USB only has 5 pins but can support full 1080p HDMI and 3D:
http://www.lindy.co.uk/usb-2-to-hdmi-1080p-adapter/42698.html
Thunderbolt has 19 pins, same as HDMI but can support dual 2560x1440 displays plus Firewire 800, ethernet and 3x USB.
I highly doubt they'd have purposely redesigned the port not knowing its capability. There must be something else going on here. There was a mention somewhere of HDCP compliance but the old adaptor obviously managed it without this complexity.
Maybe they are analyzing what you are watching and if they discover any porn being streamed to the TV, they will block the signal and report back to Cupertino.
Quote:
Mini-USB only has 5 pins but can support full 1080p HDMI and 3D:
http://www.lindy.co.uk/usb-2-to-hdmi-1080p-adapter/42698.html
No, it can't. That's a display link device.
It does support 1080p and 3D video. It's limited by the USB 2 bandwidth so they compress the input like Apple does but with micro-USB 3 (10 pins), they can support multiple 1080p HDMI outputs:
[VIDEO]
While pin count limits bandwidth, it can't be the only issue if micro-USB can support multiple 1080p outputs with 10 pins.
edit: it looks like there's a different behaviour between video mirroring and video playback:
http://www.idownloadblog.com/2012/10/24/lightning-to-hdmi-vga-adapter/
"Bad news: video mirroring is supported only in 720p, though video playback is 1080p."
So it's capable of outputting 1080p video over the connector, just not mirroring at 1080p. This issue should only affect the mirroring that the developer was using:
http://www.panic.com/blog/2013/03/the-lightning-digital-av-adapter-surprise/
One reviewer on the Apple site said there's no 5.1 audio support though on the new adaptor, which is a downgrade:
http://store.apple.com/uk/reviews/MD826ZM/A/lightning-digital-av-adapter
If these same issues with upscaling and artifacts affect video playback, that wouldn't be good at all. If they only affect mirroring, it's more likely they'll be able to fix it.
Originally Posted by Marvin
It does support 1080p and 3D video. It's limited by the USB 2 bandwidth so they compress the input like Apple does but with micro-USB 3 (10 pins), they can support multiple 1080p HDMI outputs:
How soon do you figure they'll swap their USB 2 accessories for USB 3 compatible versions? Given that 3's backward compatible*, you'd think they would have done it already, right?
*MicroUSB 3 being the stupidest looking port ever not withstanding, of course. But then again, Apple doesn't use it.