Support HDMI CEC

[hup]

Can the deck get support for HDMI CEC
So then turn it on my TV, will switch HDMI input

[deaddoof]

How do we break the DRM for you idea to work? Lets talk real worlds use cases. I know HDMI displays hate KVM.

[[EW] Mitsie]

Right let me make it simple for you to understand.

You have a computer, it sends signals via HDMI cable to HDMI port on the TV, all the 20 pins are sent correctly from the computer to the TV.

The computer sends a signal in binary code along the wire asking the TV for a HDCP handshake. It confirms and sends back an encryption key and the data is encrypted on one end, and then decrypted on the other.

The cable only transfers the binary data 1 meter to the correct 20 pins.

You then change the HDMI port on the computer to the Display port connection by plugging in a display port to hdmi cable instead.

The dual display port protocol asks at hotplug:

"what are you?"

The TV says "I require HDMI 1.2"

The computer then says
"Ok sending data in HDMI 1.2 format on correct 20 pins"

Computer sends HDCP request to TV, The TV doesn't care what plug or connector is plugged in, as long as it gets the correct Handshake request and data back in the correct format.

Computer sends data correctly. TV displays video and audio because it has been sent to the correct pins. It's receiving a HDMI stream doesn't care what its sent from as long as it follows the HDMI data protocol..

Now you decide to rip out the HDMI port in your TV and solder on a display port so all 20 pins in the HDMI match the 20 pins in the Display port female connection.

You now plug a display port to display port cable.

The computer says "What are you"

The TV says "I require HDMI 1.2"

The computer then says
"Ok sending data in HDMI 1.2 format on correct 20 pins"

As long as the 20 pins receive the correct data, the HDMI data will work regardless of cable or Connnector..

Why can't you grasp the basics?

[deaddoof]

The TV says "I require HDMI 1.2"

The computer then says
"Ok sending data in HDMI 1.2 format on correct 20 pins"

Where is my key? HDMI mafia put the key under NDA. How do I get my key to lie to my TV and say I am a HDMI compatible aka breaking DRM?

Computer sends HDCP request to TV, The TV doesn't care what plug or connector is plugged in, as long as it gets the correct Handshake request and data back in the correct format.

Computer sends data correctly. TV displays video and audio because it has been sent to the correct pins. It's receiving a HDMI stream doesn't care what its sent from as long as it follows the HDMI data protocol..

Without breaking HDCP crack. I might as well speak to the TV in spanish. TV doesn't speak spanish.

https://youtu.be/akxU62laPMk?t=1012

[[EW] Mitsie]

Your arguing about something completely different again.. We are talking about data transfer between two certified HDMI devices regardless of cable or connector. It's clearly going over your head, because your saying about trying to crack HDCP..

Forget it, it's like talking to a brick wall..

[deaddoof]

引用自 EW Mitsie：

Your arguing about something completely different again.. We are talking about data transfer between two certified HDMI devices regardless of cable or connector.

Don't care. Standards about supporting everything to make stuff work. HDMI sucks because it works under very narrow circumstances. Some of us like our freedom.

It's clearly going over your head, because your saying about trying to crack HDCP..

Almost every cool use case is consider snooping. You might as well crack it to make anything work.

Forget it, it's like talking to a brick wall..

Ah yes. Throw out other people's real world use cases. Nice. People must love you when their stuff they brought doesn't work.

[[EW] Mitsie]

HDCP works the similar to SSL in the web world. To prevent snooping. It has nothing to do with connecting two devices to send data. It's to prevent a man in the middle attack on copyrighted content..

Can't you not grasp that?

[deaddoof]

引用自 EW Mitsie：

HDCP works the similar to SSL in the web world. To prevent snooping. It has nothing to do with connecting two devices to send data. It's to prevent a man in the middle attack on copyrighted content..

Can't you not grasp that?

Why does a cable standard need to prevent snooping? What type of middle man attacks exist because I connected a cable I own into a device that I want to trust?

We are not talking about wireless signals which are a giant vulb. No. We are talking about a dumb cable which should have less privileges than a thumb stick drive.

Can you not grasp hdmi is a giant pain for anyone who want to do cool things with it?

[[EW] Mitsie]

Because people can make HDMI splitters and then make a copy of copyrighted content. HDCP protects content from being stolen by sending a encryption key from one DEVICE to the other DEVICE..

What has that got to do with data transfer between two legitimate HDMI certified devices? Nothing..

Forget it, I can't be bothered with this argument. Please look it up, or go on an electronics course and learn something..

[deaddoof]

引用自 EW Mitsie：

Because people can make HDMI splitters and then make a copy of copyrighted content. HDCP protects content from being stolen..

What has that got to do with data transfer?

My god. HDMI is broken on default. People will always be able to steal copyright content. The reason why we are having an HDCP conversation because it is the elephant in the room. You probably understand HDMI well. I do not care. I touch enough broken crappy standards to realize TV manufacturers and other display manufacturers will screw it up.

[deaddoof]

What has that got to do with data transfer between two legitimate HDMI certified devices? Nothing..

Ahh. Yes. Certified... aka anything HDMI mafia do not give two craps about. You might as well pretend it doesn't exist.

HDMI mafia inserted themselves as an elephant in the room. You cannot wish away real world problems by citing the cable only. The environment matters too.

Edit: If anyone wonder why I would blab about DRM, it turns out it's a big deal. HDMI mafia is pretty well known to block AMD from providing HDMI 2.1 driver support for Linux. HDMI 2.1 is needed for VRR on HDMI. Yes, it affects the steam deck. How would Valve provide hdmi - cec support without making more parts of the linux more pain in the ass?

https://gitlab.freedesktop.org/drm/amd/-/issues/1417

HDCP is pretty well known to break if you sneeze at it too. I believe 3 degrees of DRM restrictions and the TV will enable the highest one when you open HDCP content like netflix. Regardless of any technical merits HDCP committee created, the connector is designed to break in common situations. I heard the handshake breaks if the cable is long enough.

[deaddoof]

引用自 EW Mitsie：

Forget it, I can't be bothered with this argument. Please look it up, or go on an electronics course and learn something..

Ahhh. Yes the toxic argument. Ignore customer integration issues. HDCP comes up when they plug in the TV and the consumer wonders why it takes seconds for a picture to appear or wake up the damn TV.

Suggesting a solution without caring how it is reliable is extremely toxic. In Linux, we have this distro suggestion problem. You are pulling same arrogant argument.

We are talking about needing a talkative protocol from the same people who cannot even get ethernet over HDMI working. Right....

[Archon810]

All the bickering above aside, Valve, can you please bring this feature that one would expect from a gaming console in 2024 to the Deck please?

[deaddoof]

引用自 Archon810：

All the bickering above aside, Valve, can you please bring this feature that one would expect from a

Unless you specify your TV model, expect support to take years. HDMI CEC is known to be a giant mess. Valve will need to work on target coverage for a subset of consumers at a time. This stuff will take years to decades with a huge efforts between end consumer volunteers and maintainers.

The mess is bad enough it cannot be called a standard. This whole bickering is due to how the HDMI mafia made HDMI a rather crappy connector with politics. Interoperability goes down the drain in the name of IP protection. Consumers deal with the fall out of bugs to the point where you wonder if its worth it.

https://news.ycombinator.com/item?id=30870549

gaming console in 2024 to the Deck please?

You do realize other game console have issues with HDMI CEC too. It's 2024 and TV manufacturers somehow made TV less reliable.

hat being said, I indeed have the feeling that CEC is specifically badly implemented by most people.

I feel like the standard is rather under-specified (or there are things I don't understand), like it's said how some kind of devices are supposed to behave based on some commands, but no explanation as to how other devices are supposed to behave on those commands.

For instance, it is specified that a Player (there are various types of devices in CEC, more on that later) can send an AVR (which is different kind of CEC device, there can only be one in the whole network) volume commands. More specifically, a Player can send an AVR VOL+ and VOL- key presses to change volume. What happens if you send VOL+/VOL- to a TV? That's not specified until 2016 with CEC 2.0. So you can't control volume on most TVs if you don't have an AVR.

The number of "slots" available per device kind is constant: exactly one TV, exactly one AVR three players, 4 tuners, 3 recorders. You have a tvbox, and three game consoles (all shold be Players)? Well someone will have to lie and become a tuner or a recorder, or they won't be allowed on the bus.

Another thing that makes this messy, is that CEC needs to fit in small power budget during suspend. For instance, in Europe, the legal power budget in sleep is 0.5W. This means that your main application processor can't handle CEC in suspend. Usually, this leads to multiple "concurrent" CEC stacks, running in different CPUs, switching from always-on Cortex-M, to full-blown Cortex-A (and then you add Android TV on top of that with its own CEC stack, and you get three CEC stacks co-working together). Often the communication pipeline between those people is pretty light, and going through all those layers, you might end up losing the info of whether the wakeup instruction came from your remote (so you legit want to have the TV wake to you), or from CEC (so you want to let TV decide of the output).

I believe one gigantic factor is that CEC has started very poorly (no matter the reason), and since then, interoperability problem has been considered by most QA as "yeah well, this is life"

https://arstechnica.com/civis/threads/hdmi-cec-weirdness.♥♥♥♥634/
https://www.reddit.com/r/hometheater/comments/18ea7td/why_is_hdmicec_so_unreliable/
https://www.trustedreviews.com/how-to/hdmi-arc-and-cec-not-working-try-these-fixes-4041394
https://www.neogaf.com/threads/xbox-series-x-s-hdmi-cec-is-bad.1576831/

[Renn]

Microsoft, Sony, Nintendo, Google, and every other crappy TV box manufacturers are able to figure out HDMI CEC I don't see how it suddenly comes into a "huge mess" for Valve.

[Prezidentas]

引用自 Renn：

Microsoft, Sony, Nintendo, Google, and every other crappy TV box manufacturers are able to figure out HDMI CEC I don't see how it suddenly comes into a "huge mess" for Valve.

valve simply doesn't care, if they wanted a TV appliance, they would have made it.