Comment by rtpg | Hacker News Reader

Comment by rtpg | Hacker News Reader

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> Standards are different. The purpose of the standard is that Alice wants her output device to be compatible with everyone else's input device and Bob wants his input device to be compatible with everyone else's output device.

I do think there's value and a lot of work in coming up with a standard that manufacturers agree on. It's a huge coordination problem, based on the idea of unlinking a standard's success with the success of, say, a hardware competitor. It's real work! And like.... HDMI is an invention, right? If that isn't then what is?

"we should have drivers for the hardware that relies on this tech" just feels like an obvious win to me though. The (short-term) ideal here is just the forum being like "yes it's good if HDMI 2.1 works on linux" and that being the end of the story

I don't have much love for things that mean that like VGA info online all being "we reverse engineered this!!!" so they're not my friends but I wouldn't succeed much at standards coordination

> I do think there's value and a lot of work in coming up with a standard that manufacturers agree on. It's a huge coordination problem, based on the idea of unlinking a standard's success with the success of, say, a hardware competitor. It's real work!

It's work they would be doing anyway because they all benefit from it, which is why it isn't a coordination problem. The known and effective coordination solution is a standards body. Everyone sends their representative in to hash out how the standard should work. They all have the incentive to do it because they all want a good standard to exist.

Moreover, the cost of developing the standard is a minor part of the total costs of being in the industry, so nobody has to worry about exactly proportioning a cost which is only a rounding error to begin with and the far larger problem is companies trying to force everyone else to license their patents by making them part of the standard, or using a standard-essential patent to impose NDAs etc.

> And like.... HDMI is an invention, right? If that isn't then what is?

It's not really a single invention, but that's not the point anyway.

Patenting something which is intrinsically necessary for interoperability is cheating, because the normal limit on what royalties or terms you can impose for using an invention is its value over the prior art or some alternative invention, whereas once it's required for interoperability you're now exceeding the value of what you actually invented by unjustly leveraging the value of interoperating with the overall system and network effect.

> It's work they would be doing anyway because they all benefit from it, which is why it isn't a coordination problem

HDMI: tech is shared between you and competitors, but you don't get to collect all the licensing fees for yourself

Some bespoke interface: you can make the bet that your tech is so good that you get to have control over it _and_ you get to license it out and collect all the fees

in the standards case, the standards body will still charge licensing fees but there's an idea that it's all fair play.

Apple had its lightning cable for its iPhones. It collaborated with a standards body for USB-C stuff. Why did it make different decisions there? Because there _are_ tradeoffs involved!

(See also Sony spending years churning through tech that it tried to unilaterally standardize)

> HDMI: tech is shared between you and competitors, but you don't get to collect all the licensing fees for yourself

> Some bespoke interface: you can make the bet that your tech is so good that you get to have control over it _and_ you get to license it out and collect all the fees

Except that these are alternatives to each other. If it's your bespoke thing then there are no licensing fees because nobody else is using it. Moreover, then nobody else is using it and then nobody wants your thing because it doesn't work with any of their other stuff.

Meanwhile it's not about whether something is a formal standard or not. The government simply shouldn't grant or enforce patents on interoperability interfaces, in the same way and for the same reason that it shouldn't be possible to enforce a copyright over an API.

> HDMI is an invention, right?

DVI was an invention.

HDMI just added DRM on top of it.

That's definitely a thing that happened, but it's minimising so much other important work that it's misrepresenting the whole thing.

Do you know how much bandwidth six channels of uncompressed audio needs? Home theaters would be a HUGE hassle without a single cable doing all that work for you.

ADAT Lightpipe supports up to 8 audio channels at 48 kHz and 24 bits - all using standard off-the-shelf Toslink cables and transceivers. MADI can do significantly more.

Let's not pretend surround sound is a nearly-impossible problem only HDMI could possibly solve.

I... think you might be proving my point for me? The ability to have a single cable that can do video AND a bunch of audio channels at once is amazing for the average joe.

Don't get me wrong, I use optical in my setup at home & I'd love to have more studio & scientific gear just for the hell of it, but I'm the minority.

I'm not trying to defend the HDMI forum or the greedy arsehole giants behind them. The DRM inbuilt to HDMI and the prohibitive licensing of the filters (like atmos) is a dick move and means everything is way more expensive than it needs to be. Was just pointing out that parent's comment was reductive.

> Do you know how much bandwidth six channels of uncompressed audio needs?

Yeah.

Half the bandwidth of USB 1.0.

Or, in terms of more A/V kinds of things, about two percent of original firewire.

Correct! Now put that USB cable _inside_ a DVI cable, magically solve all the buffering problems that plagued the industry for several decades, slap on some DRM over the top, and you'll have HDMI 1.0 :-D

You just replied to someone who explained it was about the DRM, with 'nuh-uh."

Pivot much?

The rest of the capabilities were all being done for over a decade before HDMI came out, and quite well by some companies.

Sure, firewire was typically used for video plus two channels of audio, but it's a single twisted pair, and HDMI uses 4 high-speed twisted pair to transmit clock and data, plus another few pins for out-of-band signalling information.

Technically, HDMI is actually a huge failure. It wasn't until 2.1 that they started supporting compressed video.

Take a system, figure out where it has the highest possible bandwidth need, and then insert the communication cable at that point. Yeah, that's the ticket!

Before HDMI, some equipment did AV sync really well, and even after HDMI came out, some TVs still didn't do the A/V sync very well. The correct buffering for that has nothing to do with the cable, although it might seem like it because when the audio comes out of the TV, the circuits in there sure ought to be able to do delay matching.

The adoption of HDMI was, in fact, completely driven by HDCP.

I replied to someone who claimed HDMI's only purpose was DRM, which is wrong.

I haven't pivoted since the start of the thread. There simply was not a digital solution that could negotiate then stream video and AND 2+ channels of audio, all in one cable, that was supported by more than a small fraction of consumer and industry devices at once. Firewire (which you seem fixated on), for all it's many technical superiorities, had almost zero market with Windows users, or consumers in general. Set-top boxes used it in the US, but was uncommon outside of the US. Camcorders used it, but in 2002 when HDMI came out most people were still using film camcorders IIRC; digital only really became commonplace well after HDMI gained footholds.

I'm not saying the cable itself controlled clocks and handshakes, I'm conflating terms over the last couple of comments. I'm referring to HDMI, the cable, the protocol, and the connectors. And yes - HDCP had a huge part in how HDMI was pushed, which is both bad (introducing proprietary bullshit's never great) and good (larger adoption of standards that work well in the field).

Was HDMI perfect? FAR from it. But all these "there was this tech that did THIS facet better" is missing the point that I've stated a few times. It was a good solution to a number of small problems.

I'll upvote you because you're mostly right.

But to be fair, there is a standard that could have been used for digital video, SDI/HD-SDI, but the transceivers were expensive and it doesn't support any form of bi-directional handshake. There was already prosumer kit, mostly in the US, which had SD-SDI connections as an alternative to component. It didn't get popular in Europe mostly because of SCART.

I was once talking with someone who was very much involved in the process of standardising TV connectivity, a senior engineer at Gennum, and he said it wouldn't have been practical and SDI couldn't have been competitive with HDMI.

Personally, I would have loved the idea of some kind of SDI with return path signalling, like a test probe connector: https://w140.com/tekwiki/images/thumb/8/86/Tek_Interface_Evo...

Oh, for sure. That and ADAT are great examples of tech that worked and worked well - and maybe even instrumental in HDMI's later adoption of optical tech in their cables.

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