The Lightning Digital AV Adapter Surprise
panic.com
panic.com
Maybe I'm missing something, but I feel like Lightning is just the next Firewire without all the usefulness that FW had (low latency, dedicated bus that wasn't USB, lots of pro audio gear that worked with it, ability to daisy-chain, faster real-world speeds than USB, near-ubiquity before FW800 came out, super small form factor (the 4pin is tiny; not much bigger than a lightning)).
I first heard about Lightning just 2 days ago. I'm now confused between Thunderbolt and Lightning, and frustrated that I'll have to go learn about their differences.
And Thunderbolt is still the all-in-one replacement for all wired connections. So apparently the purpose behind the Thunderbolt connector subsumes the purpose behind the Lightning connector, yet the existence of Thunderbolt does not obviate Lightning's existence.
Sorry for the slow uptake, Galileo ;)
That said, the design for this AV adapter is puzzling. I wonder what the hardware limitation was that prevented straight digital video out. (# of pins?)
The cynic in me says this is an end-run around any DRM issues giving access to that 1080p bitstream could introduce: instead let's just output a degraded, upscaled stream and call it HD.
However, MHL-through-Lightning might have prevented the AV adaptor having a daisy chained lightning socket of it's own. Maybe that's why Apple jumped through these hoops.
This allows them to support different formats in the future, for instance, say when HDMI isn't popular.
The 30 pin connector didn't have HDMI on it at the time it was created and they have repurposed pins over the years regularly.
Here they can have a much less complicated solution-- a standardised serial bus over which they can stream any future protocol they want to support.
It's a lot more future proof.
It would have been just as easy to use micro-usb 3.0, which had plenty of bandwidth, and do the exact same pin or format conversions.
Standardized serial buses that are less complicated already existed. What exactly do you think USB 3.0 is?
If the only reason for lighting was "a general purpose next generation serial format", then it is definitely a horrible idea.
Of course, none of this (except DRM concerns) answers why they'd not bitstream the format and convert it to HDMI signaling instead of doing the weird crap they did here.
I'm gung-ho for Lightning but if it turns out to be nothing more than a fancy way to make USB expensive and proprietary I'll be having another think. If it guarantees accessory compatibility for 6-10 years it's worth a couple compromises but I do expect 1080P output as advertised.
It makes sense...
The lightning connector doesn't have enough bandwidth to drive a HDMI connexion directly
Of course, compressing (inside the iPad) for streaming, sending this through a limited bandwidth channel and then decompressing is complicated, but looks like it's the easiest solution (because all components - especially sw ones - are off the shelf)
It's like a mini Raspberry-pi in that adaptor, amazing! (if not slightly overpriced)
What a wonderful age we live in. How long ago was it that people doubted the Rasberry-Pi could be delivered at such a low price?
One of those rare moments where movement to the future is evidently palpable.
Because once you accept Lighting as the connector, there is no "dumb". You have USB and this is where you have to start. You don't get DVI/HDMI signals, analog audio, or anything else.
And people have answered this convincingly. From comments on TFA:
= = = = =
The reason behind this stupid expensive solution: It seems that the lightning connector is similar to the thunderbolt connector idea.
With USB you have Power/USB/MHL output. Each method requires a specific combination of pins. Updating to a different protocol, support for other devices requires difficult pin sharing (thus hardware modification), support for currently unknown future connections is impossible. If in the future something new appears it won’t work with older USB devices.
With lightning you can connect anything. Similar to thunderbolt it does not use a specific protocol to handle a specific task. It uses a general method to communicate between adapter and iOS device. That way Apple can send anything through this lightning adapter. The adapter itself gets updated automatically because it loads its firmware from the used device. So Apple can send USB2.0, USB3.0, Analog audio, Digital Audio, HDMI and any new standard through it, in theory.
The idea is great: The lightning adapter will be Apples only port and it will remain future proof.
In reality however, the lightning connector also has a limited bandwidth thus they have to compress their data, the conversion to and from the Apple lightning protocol requires lots of processing power, on both sides, and reduces quality. And finally it’s expensive.
Apple should have tried to use thunderbolt instead of their own propietary technology, but then they would have used a common technology which other manufacturers could use and benefit from, too, that’s not the way Apple likes it, so they introduced their own thing, which is crap right now.
AND:
Just remember, this is v1 hardware for a tough future proofing problem. I genuinely appreciate the lengths Apple went through to create A) a reversible plug, so you can stop mashing and flipping. B) handled all the connector options. The built in decoder module could take a compatible 1080p video stream and push that to the TV at full resolution, the screen mirroring is a separate protocol. Now I’m curious if the Lightning-SVGA adapter has the same rig!
So, v1 of the Lightning connector is probably (assuming) going at USB2 speeds. In v2 of the connector we could see USB3 (5Gbit/s) or thunderbolt (10Gbit/s) speeds, but all the accessories still work.
Assuming the faster speeds come, it’ll support 4K TV output video streams, same plug. Yay future.
http://store.apple.com/uk/product/MD826ZM/A/lightning-digita...
1: http://en.wikipedia.org/wiki/Mobile_High-Definition_Link#Mob...
I'm disappointed because Lightening was billed as the next innovation in design, but if the picture quality is worse then what's the point?
Hardly anyone will use the HDMI out. Prioritizing the plug seems like the correct tradeoff to me. And make no mistake, this is what this is. It’s always about tradeoffs.
Is it possible that it could play 1080p video, but the on-device encoding is limited to 1600x900, so can't mirror at 1080p?
[1] http://www.devttys0.com/2012/11/reverse-engineering-serial-p... (although JTAG is probably much more likely if anything)
The brown ones a most likely capacitors.
Also, for jailbreakers: find that code, and improve it.
Finally: I find it a pity that Panic reports this now. It would have been funny if it were published exactly one month later (or is the clock in their CMS off by a month?)
I heard somewhere that the Apple lightning cable, that comes with newer iPod, iPhone, iPads contains a chip and we'll be very hard to replicate (by Chinese cloners). Any insight on this?
* Jail break this cable, if this has some OS, use instead of raspberry Pi * is Apple bringing Android ADK style interfaces
I think what's most likely is the phone is putting out a h264 stream and the chip is just decoding it. Rather than a whole ios stack & AirPlay protocol.
Sure this shares some similarities with how AirPlay works (showing a h264 stream from the device ) but wouldn't require a whole system on a chip just for showing this feed.
Also. Jimmy Hoffa is buried inside that microcontroller. I won't corroborate this further, but this is the dead-on truth.
It doesn't prove anything, but it certainly fits the context. I would say the theory (and the extra bit of information) merit being analyzed further.
FWIW, a "stub copy of iOS" would mean in this context "a copy of iOS where every OS function is stubbed except what's necessary to run AirPlay."
that gives me less confidence, not more.
At least, If someone handed me one of these dongles with a copy of the protocol spec and asked me to write the software for it, I'd do something similar except using Linux. (Sidenote: buildroot is great for creating embedded systems running Linux.)
If it really works like that it's kind of brilliant. Future devices will have better mirroring output due to better hardware encoders (I haven't scrutinized the mirrored output from an A6, it may already be a lot better than the output pictured in the post). It ought to work with every Lightning device. The only question is future video format support, but since it's limited to 1080P it's probably future proof enough.
Based on the anonymous comment in this thread and this tweet, I'm potentially happy to eat my words. https://twitter.com/jmreid/status/306987650001301505
I've tweaked the post to make it clearer that AirPlay isn't _necessarily_ the _exact_ mechanism being used! It could just be H.264 or MPEG or whatever.
Mostly I'd love to know exactly what this chip/system does, so if anyone here with far more advanced hardware knowledge than any of us have feels up to hacking around, that'd be amazing! :)
The key takeaways from the post are:
1. It's feels unusual that a AV adapter would have a full SoC ARM-based CPU with RAM etc, not just a video encoder/decoder chip. Is it unusual? Let me know. :)
2. It's a bummer that the Video Out isn't very good, and not true 1080p, and has MPEG artifacts.
(Thanks for sharing the link.)
For your two points:
1. I think that comes with the territory of being a Lightnin accessory and makes sense if they're doing some sort of compression or something before hand. It certainly fits with Apple's persona. Control the content, don't let any-old-body create a video adapter. They have to deal with Apple's handshake/stream/whatever because Apple doesn't pin-out the HDMI for the Lightning connector...
2. That is a major bummer and seems like one of those "details" that Apple would get right. I'm certainly curious the more I think about it as well.
Its converting an encoded steam to HDMI output. There aren't enough pins on a lightning connector to directly output HDMI and even if it could, you still need a transceiver somewhere (not particularly trivial in terms of space or power to stuff in the phone).
The SoC is most likely a little ARM core to manage stuff (Cortex-M0/3) with a video decoder and HDMI transceiver, the 256MB of ram is there primarily for the decoder to use. It also needs to mux the audio stream into the HDMI encoding.
As for 'it runs iOS', your really splitting hairs, its pretty normal for the master devise to load a slave device with its firmware when plugged in (rather than storing the firmware in flash on the slave). The fact that they would use some knocked down version of iOS isn't terribly surprising. Embedded versions of more powerful OSs are used all the time; There is a non-zero chance your stove and microwave are 'running linux'.
Unless Linux comes with a BSD license, there is, in fact, zero chance. Apple is known to run a NetBSD variant on the airport routers - I'd say that is what is likely or whatever the hell a "stub version of iOS" means.
If you go here: http://opensource.samsung.com you can see that they have the OS for some TV's. This is the typical way they comply (with unuseful, unannotated giant dumps).
LG actually has some appliances:
MicroUSB+MHL accomplishes the same thing quite well on the current crop of Android phones. Why Apple chose the method they did is still quite odd.
Apple already made a strong commitment to AirPlay, so they already had a focus on building a fast, smooth, low power encoder that could encode the entire screen. Once encoded, the stream is probably only a few Mbit/s, a data rate that can easily be transmitted with single ended protocols like SPI. Almost all SoCs already have multiple SPI buses so no need to change any hardware.
Their solution may seem inelegant to some, but I think it is great. They managed to support a feature with almost zero hardware costs on the core device (depending on how you assign the lightning connector). A feature that I'm willing to bet only a very small % of all users will ever use. That is a big win, not having to dump extra hardware into a device that only 5% of all users will ever activate does great things for your margin and design flexibility.
Lightening is a SERIAL FORMAT with 9pins. So it streams audio and video out in an encoded form.
The AV adapter, need to take that audio and video and turn it into a standardized AV format for the AV plugs.
Now, rather than a lot of odd incompatibilities because Apple added new features to new devices that older docks don't support, we have a common communication format in lightening that should be much more robust going forward.
Apple can add whatever protocols it needs over the serial connection to support future tech, rather than the old way of redefining what some of those 30 pins meant from period to period-- remember the 30 pin connecter started out in a time when there was firewire taking up some of those pins!
People like to ascribe nefarious purposes to Apple or claim apple is "rippng them off" because a small computer that does digital AV conversion costs $30... and they dont' realize that the 30 pin connector didnt' do any conversion of formats was just bringing the signals out to a standard connector. This one actually has to do work, which is why it has a SoC on it.
So yes you get your 30$ worth of components but it's horribly inferior to a 5$ adapter you can get for every other connector on the planet. It's a rip off alright.
Perhaps Apple should think of such things first, before "future proofing" things.
Despite your defense of them, and whether there was any merit.... this change has the benefit of netting Apple a healthy profit, and rendering billions of dollars of accessories obsolete.