Talk:HDMI

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This article uses American English dialect and spelling.
According to the WP:ENGVAR, this should not be changed without broad consensus.

Specification defines an HDMI cable as having only HDMI connectors on the ends[edit]

Adaptor cables contravene current HDMI spec, and may not be "allowed" to be sold? http://www.techradar.com/news/home-cinema/thousands-of-apple-hdmi-cables-must-be-withdrawn-976455 http://www.pcmag.com/article2/0,2817,2388289,00.asp http://mobile.pcauthority.com.au/Article.aspx?CIID=263280&type=News It looks like old news but when I was trying to find out why HDMI to DVI cables are currently nearly impossible to obtain (in rural Australia, at least), I could find no useful information anywhere. If anyone is up to date on this perhaps the subject would be worth a sentence or two? HuwG 203.208.123.81 (talk) 07:43, 29 October 2012 (UTC)

The requirement is that certified HDMI cables must have a HDMI plug connection on both ends of the cable. The press section of the HDMI website gives an explanation about that requirement and it states that dongles that convert from a different cable type to a HDMI receptacle connection are allowed. While DVI to HDMI cables can't be certified I still see them for sale on the internet, and at retail stores, so I don't think that HDMI licensing is trying that hard to get rid of them. --GrandDrake (talk) 00:09, 25 May 2013 (UTC)

What is RedMere and how does it work?[edit]

I've heard of a technology called RedMere it is supposed to allow "up to 65 feet (20 meters) at the full 10.2 Gbps data throughput" (http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10240&cs_id=1025501&p_id=9167&seq=1&format=2). What is it? How does it work? Does anyone know? — Preceding unsigned comment added by 68.228.41.185 (talk) 22:01, 19 December 2012 (UTC)

RedMere HDMI cables use active amplification which allows them to have much longer cable lengths than passive HDMI cables. Active HDMI cables contain a small chip that boosts the HDMI signal. Active HDMI cables are usually more expensive than passive HDMI cables but are useful if you need a HDMI cable longer than 5 meters. --GrandDrake (talk) 00:14, 25 May 2013 (UTC)

Critial omission in not mentioning severe limitations[edit]

This article comes off as a sales piece, since it is essentially silent on what makes HDMI so costly and difficult for consumers to use, and practically impossible to use over many distances needed in typical home uses. For example, HDMI is crippled in its ability to transmit over anything longer than just a few meters because it uses a parallel signal transmission method, instead of serial communications used in every other modern transmission protocol.

Until this article addresses all such significant consumer issues, I will continue to assume that firms with a financial interest in HDMI will continue to control the article content. — Preceding unsigned comment added by 67.171.190.119 (talk) 23:23, 20 May 2013 (UTC)

The limits of HDMI are due to the high data rate that it uses combined with the low cost signalling method. HDMI at full bandwidth works with passive cables at up to about 5 meters in length. DisplayPort has a higher data rate but at full bandwidth works with passive cables that are up to about 3 meters in length. Neither standard uses serial data transmission since that would either reduce the data rate or increase the price. --GrandDrake (talk) 04:44, 24 May 2013 (UTC)
You may want to have a word with the manufacturer of the cable that I use to connect my PC's HDMI port to my AV unit in my living room. The cable is 20 metres long. It seems that both the manufacturer and the cable are unaware of this limitation. DieSwartzPunkt (talk) 08:53, 24 April 2014 (UTC)
The maximum HDMI cable length depends on bandwidth, cable quality, and whether the cable includes a signal amplifier. --GrandDrake (talk) 19:17, 27 April 2014 (UTC)

My hope was to learn some technical details of the specification. It appears, but is not 100% clear from this article, that to even read the specification you have to be a member of the forum ($15 grand sign up?!). It would be helpful if this was spelled out up front one way or the other, so that people didn't waste their time looking for information that does not exist. — Preceding unsigned comment added by 184.71.25.218 (talk) 21:20, 23 October 2013 (UTC)

Error in version comparison table (HDMI 2.0 refresh rates)[edit]

I am pretty sure that there is an error in the table listing the maximum resolution for HDMI 2.0 at different color depths. Specifically, I think anything more than 24 bits per pixel can not be shown at 60 frames per second at 4k resolutions (e.g. 4096×2160p60 at 48 bits per pixel would take 4096*2160*60*48/1e9 = 25.5 Gbits/second excluding overhead, well in excess of what HDMI 2.0 can deliver).

News articles I have seen have said that 8 bit color (24 bpp) can be shown at 4k and 60 hz, and 48 bit color can be shown at 4k (but with an unspecified refresh rate). (e.g. see http://www.theregister.co.uk/2013/09/04/hdmi_20_spec_published/ )

I am not knowledgeable enough about this topic to make the appropriate changes, and it might be that more info will be forthcoming in the next few days. — Preceding unsigned comment added by 67.82.65.131 (talk) 00:51, 5 September 2013 (UTC)

I removed some unverifiable information from the table. --GrandDrake (talk) 01:14, 5 September 2013 (UTC)

Will HDMI 1.4 cables work with HDMI 2.0 devices?[edit]

Will HDMI 1.4 cables work with HDMI 2.0 devices? Thanks — Preceding unsigned comment added by 71.131.3.194 (talk) 02:57, 28 September 2013 (UTC)

This isn't that clear. You simply cannot put 600Mhz where before only 300Mhz would work. However, you may not need to. Tafinho (talk) 22:05, 19 June 2014 (UTC)

HDMI 1.4 and CEA-861-D vs CEA-861-E[edit]

The article says HDMI 1.4 uses the CEA-861-E video standard while referencing a SiI9389 datasheet that mentions HDMI 1.4 and CEA-861-E compliance. However, I'm reading the actual HDMI 1.4b specification and it makes no mention of CEA-861-E, but talks about CEA-861-D... Anssi (talk) 00:02, 31 October 2013 (UTC)

Accessibility[edit]

This article needs to address accessibility of the HDMI standards. It seems like audio description for the blind can be included on one of the audio channels. The HDMI standard does not include communication access though for people with hearing loss or non-native speakers of the primary language (no streams for closed captioning data whether for deaf and hard of hearing or anime/foreign language) so in order to use HDMI with captions, the originating equipment must decode the data and pass the generated pictures of text to the end equipment. This limits the accessibility for persons with hearing loss, especially those with visual impairments. Televisions in the United States are required to have closed caption decoder chips and the visibility can be changed to the user's liking for over the air or Video/Audio inputs but this does not work for HDMI inputs since they do not pass the caption data through. This limits the ease with which physically disabled persons can use captions since they cannot just turn their television caption decoder on once and be done, they must turn on captions on each piece of sending equipment when using HDMI. This makes it harder for children and the aged to gain ease of use for captions. This also increases costs for everyone as with HDMI all of the sending and receiving units must have decoder chips (receiving units/televisions for over the air caption data.) — Preceding unsigned comment added by 2602:30A:C049:EA80:4885:EA70:59A9:82AB (talk) 18:30, 9 June 2014 (UTC)

600Mhz Source and existing cables compatibility[edit]

There is no source for the 600Mhz TMDS frequency value. Also, there is no independent source for the compatibility for existing 1.4 cat 2 cables, apart from the HDMI forum. Tafinho (talk) 22:06, 19 June 2014 (UTC)

Several sources mention 18 Gbps for HDMI 2.0 so based on how HDMI works that would mean a TMDS clock rate of 600 MHz. I have added two references for the TMDS clock rate. As for compatibility with older cables it would depend on the cable but almost all HDMI cables are made out of copper cable. As long as the bits are correctly transferred over the copper cable it doesn't matter if the cable was designed for it. --GrandDrake (talk) 21:31, 28 June 2014 (UTC)

HDMI 2.0 references[edit]

Back when i added a section about HDMI 2.0, I added some references to convince everyone it was real. But since equipment with HDMI 2.0 is actually on the market right now, do we really need four references per statement in the HDMI 2.0 section? PizzaMan (talk) 18:40, 16 July 2014 (UTC)

There are only two secondary sources. I have marked primary sources and raw press releases. Perhaps those should be removed. ~KvnG 03:07, 23 July 2014 (UTC)