It may be worth adding "(2016)" to the title, otherwise people are going to think like this dead tech is somehow relevant today ;)
If you're confused, read https://arstechnica.com/gadgets/2023/01/hdmi-to-usb-c-spec-a...
HDMI Alt Mode for USB Type-C Connector
31–40 of 53 posts
Re: HDMI Alt Mode for USB Type-C Connector
#32How is this relevant considering DisplayPort alt mode has been a thing for a while?
It's relevant because the display just needs an HDMI port. You can plug a HDMI-to-USC-C cable into a computer and a TV or projector and it'll work using this. If your device doesn't do displayport then displayport support is moot.
Were there ever any (source) devices with HDMI alt mode shipped, though? I vaguely remember hearing about one smartphone, but that seemed more like a showcase for the technology.
Re: HDMI Alt Mode for USB Type-C Connector
#33Earlier quoted context omitted.
> The computer world pretty much standardized on DisplayPort already Do you know why that is? I live in the Apple world do I didn’t follow the changes. Last time I had a PC it was VGA and DVI, which gives you a sense of the timeline. Then it seems to have been HDMI for a while (?) and now seems to be moving to DisplayPort. Is there a reason DisplayPort over Thunderbolt didn’t catch on? Maybe something about how commo…
> Then it seems to have been HDMI for a while (?) Not really. HDMI is basically DVI++ but it's first and foremost a TV and video interface. Once DVI started to be limiting, both PCs and high-end monitors adopted DP. HDMI came to PCs and monitors later, sometimes with limitations, for instance my Dell U2711 couldn't run at its native resolution over HDMI. A few years later UHD 4:4:4 was literally impossible from a PC…
Also DP can do cool things like carrying the signals for multiple monitors (daisy chaining)... I have one usb type c cable that does power display and usb for my 2 dell monitors... it is awesome... sadly Apple never implemented DP daisy chaining this and when you try it with their hardware you only get a mirrored output.
Re: HDMI Alt Mode for USB Type-C Connector
#34HDMI Alt Mode was basically dead on arrival. The computer world pretty much standardized on DisplayPort already, so USB-C devices would already have to support DisplayPort Alt Mode anyways. Why add support for yet another Alt Mode when DP-to-HDMI converter chips are dirt cheap, and pretty much all USB-C-to-HDMI cables will be using those anyways due to the aforementioned DP ubiquity. One thing which really bothers me…
So, maybe I'm missing something here, but who is talking about computers? Most things that need to be connected to with HDMI, are TVs. I have 5, none of them take display port or USB-C. The all take HDMI. I have no "monitors" because... Why would I need one (I only "game" things that have to run on dosbox)?
But let's talk computers. And phones. All mine, only have USB-C. I have an old one that has micro, and I chromecast the screen from that one. I connect them all to TVs. With HDMI on the TV end.
So literally your dead on arrival example is not even present in the life of my household, while what's talked about in the article is widely used.
Re: HDMI Alt Mode for USB Type-C Connector
#35So… the same connector as Thunderbolt, and it can deliver video like Thunderbolt. And in both cases it’s running DisplayPort over the connector. So there were two different ways to run DP over a cable with a USB-C connector. Sounds like it’s good it’s dead.
No, HDMI alt mode was (is?) actually sending HDMI over the USB-C wire.
Thunderbolt also doesn’t really natively send DP over USB; it encapsulates it (plus PCI express) in a custom wire format.
Only DP alt mode actually uses DisplayPort at the wire level over USB-C cables or ports.
Re: HDMI Alt Mode for USB Type-C Connector
#36not a lot of details in this but I'm curious how the AC-coupled USB-C interface works with the DC-coupled HDMI. typically there would be a DP-to-HDMI convertor in the cable plug and just use DP alt-mode but this specifically says: "This allows native HDMI features and capabilities to be utilized in a source device and to be directly connected to any HDMI display. Other Alt Mode solutions do not enable HDMI-specific f…
> native HDMI features Please tell me that this is not marketing speak for HDCP! What other "native HDMI" features are there that DisplayPort does not already support?
Maybe HDMI-CEC? But at least some versions of DisplayPort also support that, including DP alt mode. Some USB-C to HDMI (via DP alt mode) adapters even advertise that capability.
Re: HDMI Alt Mode for USB Type-C Connector
#37USB Type-C is such a mistake for video connectivity. It just doesn’t work most of the time and when it works, any tiny move of the USB Type-C cable breaks it down.
it's 2023 and I can't plug my phone into a dock or monitor without fancy bits. At least I can plug in a USB and and it can act as a host. The _only_ reason I want a linux based phone is so I can just use my phone like a normal device. The software implementations (who remembers MTP?) for phones kills its usability as a general purpose device.
What do you mean by "fancy bits?". I can plug my Galaxy S23 into the same dock as my Macbook Pro and use DeX with video out and my keyboard and mouse without installing or doing anything other than clicking "ok".
Re: HDMI Alt Mode for USB Type-C Connector
#38USB Type-C is such a mistake for video connectivity. It just doesn’t work most of the time and when it works, any tiny move of the USB Type-C cable breaks it down.
This has not been my experience at all with DP in lightning and USB ports.
Lightning doesn’t support DP, does it?
There are lightning to HDMI adapters, but these fascinatingly run a full SoC that receives and decodes a compressed H.264 video stream over lightning, which I wouldn’t really call HDMI over lightning.
Re: HDMI Alt Mode for USB Type-C Connector
#39not a lot of details in this but I'm curious how the AC-coupled USB-C interface works with the DC-coupled HDMI. typically there would be a DP-to-HDMI convertor in the cable plug and just use DP alt-mode but this specifically says: "This allows native HDMI features and capabilities to be utilized in a source device and to be directly connected to any HDMI display. Other Alt Mode solutions do not enable HDMI-specific f…
> native HDMI features Please tell me that this is not marketing speak for HDCP! What other "native HDMI" features are there that DisplayPort does not already support?
Non-PCM audio (i.e. Dolby Atmos/DTS-X) and HDR10+/Dolby Vision do not appear to be supported by DisplayPort.
(Nor ARC/eARC, but I think those would be of limited utility for the USB-C alt mode.)
Re: HDMI Alt Mode for USB Type-C Connector
#40Earlier quoted context omitted.
> Then it seems to have been HDMI for a while (?) Not really. HDMI is basically DVI++ but it's first and foremost a TV and video interface. Once DVI started to be limiting, both PCs and high-end monitors adopted DP. HDMI came to PCs and monitors later, sometimes with limitations, for instance my Dell U2711 couldn't run at its native resolution over HDMI. A few years later UHD 4:4:4 was literally impossible from a PC…
Also DP can do cool things like carrying the signals for multiple monitors (daisy chaining)... I have one usb type c cable that does power display and usb for my 2 dell monitors... it is awesome... sadly Apple never implemented DP daisy chaining this and when you try it with their hardware you only get a mirrored output.
Yes, it’s a pity they never implemented that.
Presumably some deal with Intel to push Thunderbolt :/ It’s an open spec now, but at the time Apple was pushing Thunderbolt hard, only Intel was building the chips for it, both for computers and peripherals (ie monitors, docks etc.)