HDMI (High Definition Multimedia Interface) is today’s standard for transferring digital video and audio between compatible devices.
The standard variant comes as a male connector (plug) or female connector (socket). Chances are that most people will have many of these scattered around their homes, with TVs, monitors, set-top boxes, video games consoles, and dozens of other video-capable devices utilizing the interface.
It’s no surprise then that the list of companies that have adopted the HDMI standard for their products is huge, with founders including Maxell, Panasonic, Sanyo, Philips, and Sony leading the way.
Since its inception back in 2002, many versions of HDMI have been developed, each utilizing the same basic connector but with added features. While new functions aren’t available to users of pre-update hardware, the entire system is backward compatible.
These updates (which are given version numbers such as HDMI 1.0 (2002) right up to the latest HDMI 2.1 (2017)) are described in technical specifications documents. However, according to the HDMI Licensing Administrator, Inc., the licensing agent for the HDMI product, these documents are not only copyrighted but also contain secret information.
Github user ‘Glenwing’ has been archiving these documents for the last few years in his personal “Display Industry Standards Archive” but was recently hit with a DMCA takedown notice after HDMI Licensing Administrator filed a complaint against him.
GitHub itself published details of the DMCA complaint which claims copyright over the documents and further states that they aren’t for public consumption.
“HDMI Licensing Administrator, Inc. is the licensing Agent to the founders of the HDMI® Digital Interface. It has been brought to our attention that user Glenwing is publicly making confidential copyrighted content available on your hub without authorization,” the notice reads.
Since we’ve seen these documents available freely online before, we contacted Glenwing to find out what the problem was.
He told us that HDMI specification version 1.3a is available for public download from the HDMI website but considering copies of the other specifications can be found online elsewhere, he didn’t think there would be an issue putting them in one place.
“I just assumed it was something considered unimportant to them, considering there have been other hosted copies of ‘confidential’ HDMI versions that were widely linked, easily locatable by simply Googling ‘HDMI 1.4 pdf’ etc,” he explains.
“These documents have even been linked as a source on the HDMI Wikipedia page. You can’t get any more visible than that, and those copies remained online for years. But now that I’ve been revisiting my original sources I downloaded from, they’re mostly dead links. It seems HDMI Licensing may have started to clean house all over the web, not just targeting my page specifically.”
Glenwing confirmed that all copies of the specifications he uploaded to Github were just obtained from various sources on the Internet, such as Wikipedia citations or simple Google searches.
He’s clearly just a tech enthusiast with a great interest in the topic, who would like to share his knowledge with others. There’s certainly no malicious intent.
“I never really intended these documents for distribution anyway, and if I could hide the Github page from Google results with a robots.txt file or something, I would,” he says.
“I upload them primarily for my own reference, to have every version in one place, so that when I write guides trying to educate people about the capabilities of HDMI, DisplayPort, how to correctly calculate video bandwidth, how these standards have changed over time, etc., I can link these documents as sources.”
Interestingly, this takedown wasn’t the first received by Glenwing. He initially received a notice just a few days earlier from the Consumer Technology Association (of which HDMI Licensing Administrator is a member) which targeted half a dozen CTA standards documents.
“Six copyrighted CTA standards are posted in their entirety here:
https://glenwing.github.io/docs/,” the notice from CTA reads. “[T]he works are not licensed under an open source license…the best solution is removal,” it adds.
So are these documents sensitive too? Glenwing believes not.
“This notice I actually received first, and it was a bit puzzling at the time; I had six CTA documents, which are all different revisions of the same (public) standard, CTA-861 [A DTV Profile for Uncompressed High Speed Digital Interfaces]. The three latest revisions (G, F, and E) are available for free download from the CTA website, the older revisions are not, likely because they are simply outdated, not because anyone considers them secret information,” he says.
“It’s fairly common for standards organizations to only host the latest versions, and whenever a new revision is released, older versions often become difficult to find. That was sort of the point of my page, to preserve every version I could find for historical purposes.”
In the absence of his own archive on Github, Glenwing then began to link directly to pages on the Consumer Technology Association site that host the documents and offer them for download. Functionally, access to the documents should have been the same. Or at least that was the plan.
As this piece was being put together, CTA removed the copies of its own standards from its own website, leaving dead links in their place. It now appears that they can only be accessed via the CTA Store, albeit for the knockdown price of $0.00, following a registration process.
Bizarrely, there are other sources for the documents, such as this site which offers to sell one of the publicly available documents for a mere $278. People shouldn’t have to pay a penny of course, as per a May 2018 press release from the CTA which declared free document access to all….