Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

(Presumably) Apple engineer comment on Lightning AV adapter design

panic.com

Post reply on HN
Print view View original

101–110 of 175 posts

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#101

Post by ecopoesis »

XorNot wrote: post #90
coldtea wrote: post #75

Earlier quoted context omitted.

> That is a problem entirely of our own making. Aren't all problems in computing this way? > The stereo beside me has components that span 30 years and uses the same cabling for all components. Yes. And it does just one thing. Output analog electrically encoded sound signals. Now, call me again when that stereo cabling has to also support: audio out, digital audio out, video out, different resolutions, MIDI out, conn…

The real issue here though is it's a solution to a non-existent problem. This was potentially a problem before HDMI was a standard. That's no longer true though. Modern HDMI does video, audio and has an ethernet bus standard right on the cable. All Apple is doing is proprietary lock-in here - it's not more flexible in anyway, where as HDMI is signal compatible with DVI and DisplayPort.

_Modern_ HDMI supports ARC, 3D and Ethernet. The early versions didn't, and you have to upgrade components to get the functionality. Apple is solving a real problem here: next time the HDMI consortium adds another random feature to their bus, Apple can just ship a new adapter that will work with all Lightning devices since none of the HDMI hardware is in the phone.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#102

Post by morsch »

StringyBob wrote: post #77
seabee wrote: post #70

Earlier quoted context omitted.

You'd need 3Gbps to push uncompressed 1080p data. If you look at USB 3.0 and make a not-unreasonable bet that Lightning is slower, then you simply don't have the bandwidth to do so.

As well as bandwidth, power consumption. Chucking 3Gbps down a long wire is going to reduce battery life for a mobile product. Perhaps the controller can support it, but heat dissipation in the phone is significant?

I can't imagine that compressing and decompressing MPEG 4 uses less power, given specialised hardware for each task.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#103

Post by rossjudson »

His first sentence is "Airplay is not involved", and then he proceeds to tell you that all of the parts of Airplay that are responsible for the drop in quality are involved. Specifically, a compressed video stream is created and that is sent to the SoC for decompression. That compression/decompression cycle is responsible for the quality degradation in the video, and (presumably) the limitations on the output resolution.

"We didn't do this to screw the customer". Sure you did. You have offloaded the cost of a parallel connection, necessary for HDMI, to the adapter. Almost every competing system comes with HDMI built-in. 30 pin connectors could drive HDMI. Lightning can't without having another whole computer in the adapter.

What makes this actively hostile to the customer is Apple's proprietary adapter design. If there was a real, competitive, standardized market for the various adapters, on balance it would be a good deal. But there isn't.

Magsafe is nice, but if you have any of a number of common problems with your Air's power supply/cable, you are in for an $80 charge to buy a new one. Even if the only thing wrong with it is pin spring that's worth pennies.

Because Lightning is coupled to proprietary decoders and Apple patents, it's customer-hostile.

And, as we've seen here, the result has poor quality. If the quality was high, then we might be able to overlook it. We shouldn't.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#104

Post by pifflesnort »

jfb wrote: post #84
hosay123 wrote: post #79

Earlier quoted context omitted.

OK here we go, and why not, after all it's Sunday and I've got nothing better to do.. right? The central tenet was that discourse here is regularly devoid of sound engineering because it tends to be blinded by mindless cultural perceptions of the companies involved in whatever happens to be under discussion. In the case of Apple the expectation is their products are flawless and if not then all hell will be paid on b…

While I agree that there is precious little interesting technical discussion on HN, engineering is an ideological discipline, just like anything else.

I don't agree that engineering is necessarily and solely a cargo cult discipline. We have math, we have observable and repeatable experiments.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#105

Post by [deleted] »

rossjudson wrote: post #103

His first sentence is "Airplay is not involved", and then he proceeds to tell you that all of the parts of Airplay that are responsible for the drop in quality are involved. Specifically, a compressed video stream is created and that is sent to the SoC for decompression. That compression/decompression cycle is responsible for the quality degradation in the video, and (presumably) the limitations on the output resolut…

[deleted]

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#106

Post by XorNot »

glasshead969 wrote: post #100
XorNot wrote: post #93

Earlier quoted context omitted.

It still doesn't make any sense. "Here's a world standard which is being built into literally every display on the planet, and is signal compatible with many others" (i.e. HDMI/Displayport/DVI). And for some reason they're worried about some new standard being incompatible and not being able to upconvert? The exact same logic would apply if the devices had native display connectors, and then eventually needed some ne…

This isn't just about video, the design helps to keep pin smaller and removes the need to having dedicated combination of pins to support a certain standard which may not be used anymore. For example, old 30 pin connected had support for FireWire which is no longer user anymore but connecter still needed to have those pins. I think they know the issue of video quality and are working to fix that. The beauty of this d…

Except all it does is create a new problem for them, without solving an old one. If you're putting a SOC in the cable then it has to be powerful enough to talk to the new standard. So you need a custom cable and connector no matter what.

If you need a custom cable no matter what, then why not support a common standard - which is a standard and thus common to many devices - and then adapt it as necessary?

Instead you have this situation: you've got a proprietary standard which can't handle a common standard well in the first place (evidenced by the fact they made a compromise to make it work). It'd make sense if there was a lack of pins or something, but it doesn't - between USB and HDMI/DP there's every type of signalling you would need to support newer standards within the realms of the existing hardware.

It's Apple ecosystem lock in and that's it, but in this case its a worse outcome.

They're not going to be reprogramming iOS devices for faster bitrates - that means an IC change in the device. It also means an IC change in the cable. And at the end of the day still means...less capability then using standards would have.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#107

Post by larrys »

nirvana wrote: post #68
noonespecial wrote: post #30

There’s no shell in the image, there’s no utilities (analogous to what we used to call the “BSD Subsystem” in Mac OS X). It boots straight into a daemon designed to accept incoming data...(and the fact that the firmware is stored in RAM rather then ROM)... But there could be. In fact, it could do almost anything as its a powerful little computer in its own right and it sounds an awful lot like it boots the kernel and…

A little thought experiment... some clever dudes manage to reverse engineer enough to "jailbreak" this, and then they put a little OS image on it and start hacking away... then a bunch of people say "hey, this is really cool! It's like Apple made a little raspberry pi for us!" but then even more say "but it's so limited, it doesn't have USB out, etc, etc." And then dozens more just go on and on about how Apple "cripp…

"And then dozens more just go on and on about how Apple "crippled""

Exactly. "Dozens". Apple isn't building products for "dozens". They are building for the people who literally stream into the Apple retail store (non techies who clamor for their products) at all times of the day when other stores sit idle. I can walk into the Apple store near me (and it's not in Manhattan but in a suburban mall) and while the other upscale shops are idle, say, Tuesday at 10am the Apple store is quite busy.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#108

Post by rossjudson »

nirvana wrote: post #67

Ideology has trumped engineering, and as hackers, you shouldn't tolerate it. Frankly, all of this has been obvious all along to any competent engineer, since the moment Apple introduced lightening. They described it as a serial bus and talked about how it gave more flexibility. If you think about it for 2 seconds its obviously better to run protocols over a serial bus than to run 30 lines of individual signals, with…

What you're saying is true from an engineering standpoint (serial vs parallel), but has to be placed in the customer's context.

In this specific case the quality is bad, operation is unreliable, and the price is high. Consumer devices accept HDMI as input. Serial to parallel video (Lightning to HDMI) is tough without some heavy-duty hardware -- hence the exorbitant cost of these adapters.

The SoC design introduces a massive amount of complexity. This has yielded unreliable operation. And it introduces that complexity at a point of physical vulnerability -- people don't treat adapter like tiny fragile computers. They treat them like, well, adapters.

End-to-end serial communications would be nice, but that's not the world we live in.

Lightning isn't that much smaller than HDMI or Micro-HDMI. Reversibility is a very minor feature, and not worth the price being paid.

And that's not a $30 adapter. It's a $50 adapter. Did you think it was $30? That was the old one -- parallel to parallel.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#109

Post by dasil003 »

hosay123 wrote: post #73
objclxt wrote: post #72

Earlier quoted context omitted.

> defined as Apple, you know the company with the most popular open source operating system in the world? I'm not sure which OS you're talking about...perhaps you could point me to the source code of either OS X or iOS? Certain core components of OS X are open source, but Darwin isn't OS X. As someone who makes his living from writing Objective-C code, I don't have any ideological objection to Apple. But I think you…

Perhaps you didn't experience the PR storm around the time OS X was initially released: it was heavily geared towards nerds and the literal phrase "open source" was extensively employed in their marketing material. This aside, you're basically trying to write off nirvana's (IMHO excellent) rant using a minor technicality, one of the common features of the discussions here that tends to make my skin crawl.

I would tend to agree wrt HN nitpicking except in this case nirvana is presenting himself as the paragon of objectivity setting the story straight against the unwashed rabble of knee-jerk Apple haters, when in fact he is nowhere near objective when it comes to Apple, and shooting ignorant fish in a barrel is not good enough to validate his points. He needs to be held to a higher standard.

Re: (Presumably) Apple engineer comment on Lightning AV adapter design

#110

Post by [deleted] »

hosay123 wrote: post #79
nier wrote: post #76

Earlier quoted context omitted.

The technicality being that Darwin seizes to be an open source operating system once it is shipped with closed source components. Why would this be true?

OK here we go, and why not, after all it's Sunday and I've got nothing better to do.. right? The central tenet was that discourse here is regularly devoid of sound engineering because it tends to be blinded by mindless cultural perceptions of the companies involved in whatever happens to be under discussion. In the case of Apple the expectation is their products are flawless and if not then all hell will be paid on b…

[deleted]
Post reply on HN