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(Presumably) Apple engineer comment on Lightning AV adapter design

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

#11

Post by gilgoomesh »

revelation wrote: post #3
dmishe wrote: post #2

I think the main takeaway is that yes, lightning is future proof and can adapt to any output you want it to. I do wonder what's the reason for encode/decode cycle was in the first place though.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now.

Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

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

#12

Post by glitch »

revelation wrote: post #3
dmishe wrote: post #2

I think the main takeaway is that yes, lightning is future proof and can adapt to any output you want it to. I do wonder what's the reason for encode/decode cycle was in the first place though.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

So, you're saying bandwidth increase while maintaining backwards compatibility won't be possible through the Lightning interface? Surely, USB 1.0 to USB 2.0 demonstrated a counter-example to your statement.

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

#13

Post by FireBeyond »

gilgoomesh wrote: post #11
revelation wrote: post #3

Earlier quoted context omitted.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now. Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

A mere fifty per cent more than something that Lightning already can't handle...

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

#14

Post by mbell »

dmishe wrote: post #8
mbell wrote: post #7

Earlier quoted context omitted.

> If they can't even do 1080p lossless right now, they are in much deeper trouble for the future. Unencoded video is about the most bandwidth intensive thing I can imagine coming out of or going into a phone, and will remain so for a long time. 1080p30 @ 24bit is roughly 1.5 Gbit/sec before you talk about transport level ecoding (8b/10b) or audio.

But then there's 4K, if we're talking about future proofing. Well, say right now it cannot transmit 1080p60 raw. Could it with new hardware in device and adapter? Or put another way — does number of pins limit bandwidth in any way?

> Well, say right now it cannot transmit 1080p60 raw. Could it with new hardware in device and adapter? Or put another way — does number of pins limit bandwidth in any way?

Based on what has come out about lightning it appears to have 2 differential data channels (same as USB2). There will be some upper limit on frequency but its impossible to know without detailed specs. Its also not clear if one is locked as send and one as receive, or if they are configurable, there is an ancillary control channel so anything seems possible.

For comparison, HDMI has 3 data channels, each with raw bit rate of up to 3.4Gbit/sec (~2.7Gbit/sec data).

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

#15

Post by [deleted] »

FireBeyond wrote: post #13
gilgoomesh wrote: post #11

Earlier quoted context omitted.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now. Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

A mere fifty per cent more than something that Lightning already can't handle...

[deleted]

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

#16

Post by jacquesm »

glitch wrote: post #12
revelation wrote: post #3

Earlier quoted context omitted.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

So, you're saying bandwidth increase while maintaining backwards compatibility won't be possible through the Lightning interface? Surely, USB 1.0 to USB 2.0 demonstrated a counter-example to your statement.

Notice the 2.0 there?

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

#17

Post by revelation »

gilgoomesh wrote: post #11
revelation wrote: post #3

Earlier quoted context omitted.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now. Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

This isn't streaming, its the last 50cm from your computer to your display. The 200 times more of data are already handled without a sweat by today's interfaces. Dual link DVI, from 1999, can already do more than 1080p.

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

#18

Post by kalleboo »

gilgoomesh wrote: post #11
revelation wrote: post #3

Earlier quoted context omitted.

He doesn't say, but probably because they just don't have the bandwidth. And thats where all this future proof talk goes deaf. New interfaces will only have more bandwidth, thats the whole point. Meanwhile, Lightning still has the same bandwidth and theres still a considerable penalty in serializing any other interface. If they can't even do 1080p lossless right now, they are in much deeper trouble for the future.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now. Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

What I don't get is, is MHL can stream 1080p over a regular microUSB port, why can't Apple do the same? Is it that expensive?

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

#19

Post by mbell »

revelation wrote: post #9
mbell wrote: post #7

Earlier quoted context omitted.

> If they can't even do 1080p lossless right now, they are in much deeper trouble for the future. Unencoded video is about the most bandwidth intensive thing I can imagine coming out of or going into a phone, and will remain so for a long time. 1080p30 @ 24bit is roughly 1.5 Gbit/sec before you talk about transport level ecoding (8b/10b) or audio.

And HDMI does it effortlessly. That's exactly what these interfaces were designed to do: raw massive data with low latency over short distances, suitable for processing in dedicated circuits, not SOCs.

> suitable for processing in dedicated circuits, not SOCs.

Your splitting hairs. Pretty much all HDMI transmitter ICs have a microcontroller on board, they need a processor to deal with the protocol configuration, DDC and HDCP. Probably most are using some 8051 design plunked into the chip. They are SoCs by any reasonable definition.

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

#20

Post by taligent »

revelation wrote: post #17
gilgoomesh wrote: post #11

Earlier quoted context omitted.

Do you mean the future where we're streaming 4k video? If HEVC (aka H.265) lives up to its promise, 4k video will come in around a mere 50% more than 1080p does now. Meanwhile, lossless 1080p would require 20000% more space (no I didn't add too many zeros, that's 200 times more).

This isn't streaming, its the last 50cm from your computer to your display. The 200 times more of data are already handled without a sweat by today's interfaces. Dual link DVI, from 1999, can already do more than 1080p.

Sorry but are you talking about the right connector here ? Lightning is for the iPod, iPhone and iPad.

Of course dual link DVI et al can do more than 1080p. They are all huge. Apple's needs to support not just today's thin devices but those for the next decade (iWatch ?).

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