Talk:DisplayPort

message: I suggest to mark HDCP and DPCP as anti-feature Uis9936 (talk) 12:50, 3 April 2020 (UTC)
replies: text: I suggest you give reasons for your suggestions, otherwise they cannot be evaluated and will most likely be ignored. GlenwingKyros (talk) 19:09, 3 April 2020 (UTC)

text: A feature that more people can use for something than not and that can be disabled with a checkbox in video drivers (because the DP standard itself only defines the method of transmission) isn't an anti-feature; it has to be used by software or it's unimportant.  By this logic the viral nature of the GPL3 is far more an anti-feature since there's no getting rid of it and it can easily ruin someone's livelihood should they accidentally produce a binary that was statically linked instead of dynamic and make it available for download, but bring that up and suddenly there's a big ol' tent pitched for protecting IP from being appropriated and re-sold when it comes to a piece of software you checked in a one line comment fix and a bugged function that was reverted a year later to 10 years ago.   :P   A Shortfall Of Gravitas (talk) 04:17, 28 March 2023 (UTC)
thread_title:  DRM as anti-feature 

message: Hey there, I just stumbled on this in the article. The article states:
While this seems fine at first glance, the comparison is inaccurate or "not fair". If we assume that with "maximum cable length" we are talking about the specifications of each, we have the following:
* DP: According to VESA "DisplayPort is specified and tested to run 15 meters without the need for a booster station.", so we are talking about passive bog-standard cables here. However they also state that "it often can supply an excellent signal even further".
* HDMI: The HDMI article states that "no maximum length for an HDMI cable is specified" (which would already make the 30m incorrect), however it also states that "certification is difficult to achieve for lengths beyond 13 m". Why a standards body doesn't actually define a standard for how their cables are supposed to work is beyond me but that's a whole different can of worms. Either way, if we're going by what is certifiable, we'd arrive at 13m for HDMI (various other sources including German Wikipedia cite 10m, although the cited source doesn't explicitely limit to 10m either much the same as VESA does for DP).
* The 30m claim is seemingly coming from the HDMI article, however it only states that "Active HDMI cables use electronics within the cable to boost the signal and allow for HDMI cables of up to 30 meters (98 feet)". Comparing passive DP to active HDMI cables doesn't seem like a fair comparison. There are of course also DP extenders/boosters/active cables, at which point the discussion is moot because the cable length is effectively unlimited.
Now the question is should this point be removed entirely or clarified to include this disparity? Mihawk90 (talk) 11:19, 2 July 2023 (UTC)
replies: text: Yes, this bullet point should be removed. As you pointed out, neither standard specifies a "maximum length" nor would it make any sense to do so, as there is no such fixed value.  — Glenwing (talk) 16:15, 2 July 2023 (UTC)
replies: text: Done, thank you for the reply. Mihawk90 (talk) 10:25, 3 July 2023 (UTC)
thread_title:  Inaccurate feature comparison with HDMI 

message: In the table on the right there under “Electrical” are some voltages and currents specified with unclear meaning. DisplayPort doesn’t use 3.3 V for its signals. It uses differential signaling where the exact voltages aren’t specified, but the voltages (both the common mode bias and the differential voltage) should always stay way below 3.3 V. The DisplayPort connector has one supply pin though to power e. g. a DP to HDMI adapter. This pin supplies up to 0.5 A at 3.3 V. So this entry in the table could be renamed e. g. to supply voltage to make it correct. Additionally it is unclear to me, what the “Max. voltage” and “Max. current” entries mean. The latter could mean the supply current of the aforementioned pin, but then this should probably be stated explicitly. I don’t know of any voltage value that should reach 16 V, so this entry makes no sense to me. It should either be clarified or removed if there is no such voltage.
Another problem in this article is that at multiple places it talks about DP to HDMI adapters having to convert the signals from 3.3 V to 5 V. This is wrong as neither DisplayPort uses logic levels of 3.3 V (see above) nor does HDMI use 5 V logic levels. They both use differential signaling where the exact differential voltages aren’t specified, but are both way below 1 V.
--Lukas.fink1 (talk) 21:26, 1 March 2024 (UTC)
replies: text: Hi, thanks for the observations. Will review later today. I think DP specifies abs max 2.0V for Vcm and around 1.3V for Vpp, maybe this is where the 3.3V came from? (EDIT: Given the voltage listing as 3.3 V and max current of 0.5 A, this appears likely to be referring to DP_PWR) For the others, 16V etc. I have no guesses. This will need some cleanup. Thanks again for your notes.  — Glenwing (talk) 22:20, 1 March 2024 (UTC)

text: I've removed the electrical specifications from the main table since the categories themselves were quite vague and not of much value. I've also rewritten the sentence about dual-mode adapters.  — Glenwing (talk) 05:41, 2 March 2024 (UTC)

text: I notice also, many datasheets for DP dual mode level shifting ICs mention 3.3V (from DP_PWR) to 5V (for HDMI DDC) conversion, it seems likely this is the origin of that sentence, and something got lost in translation along the way...  — Glenwing (talk) 06:07, 2 March 2024 (UTC)
thread_title:  Questionable details about the physical layer 

message: Over the years, it has been mentioned on numerous occasions, such as here and here, that large portions of this article read like a technical whitepaper or manual. There is a gratuitous use of unexplained jargon and terminology used throughout that only makes sense to an expert or specialist. The first section is "Versions", which goes right into describing features like color space, link layers, Adaptive Sync, etc., which are never explained. Readers with zero knowledge of what these things mean will see this as technical jargon and find it useless. There's plenty more of that scattered throughout the article.Per WP:TECHNICAL: ""As noted in WP:UPFRONT, we need to push the highly technical portions of the article to the bottom and lead with a high-level overview that's easy to understand. A while back, we had an Overview section that followed the lead, which attempted to describe the basics of DisplayPort technology that appealed to a general audience. At some point, this was abolished and partially merged into the lead unnecessarily (which actually violates WP:LEADFOLLOWSBODY). We need to consider reinstating that section to help ease readers into the article. Eventually, I'd like to weed out as much unnecessary technical jargon as possible, but for now, pushing that to the bottom will suffice. If anyone has any thoughts, please weigh in here. I'll give it some time before making any cleanup attempts, thanks. --GoneIn60 (talk) 03:29, 4 March 2024 (UTC)
replies: text: Forgot to add that during the cleanup phase, interpretations that are only cited to a whitepaper (meaning it provides unsourced analysis of technical specs) will be removed or flagged with a  tag. Even if correct, these interpretations must be cited to reliable sources that are making that analysis for us. This does two things. First, it removes any doubt that the analysis is not WP:OR. Second, it shows significance that the detail in question qualifies as WP:DUE. --GoneIn60 (talk) 03:37, 4 March 2024 (UTC)
thread_title:  Technical nature of the article