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Following up from an earlier question, it appears that DisplayID is

designed to replace E-EDID standard and EDID structure v1.4.

How do I get this structure from my monitor? Neither xrandr --verbose nor sudo get-edid mention it.

The purpose of this was to tease out information relevant to enabling 3840x2160 resolution at 60 Hz vertical and 4:4:4 chroma subsampling while resolving ghosting and striping issues. In my specific case (Samsung TV) it turns out I simply had to turn off all the fancy image post-processing and enable "HDMI UHD Color" and "Game Mode".

l0b0
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1 Answers1

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How do you know your monitor even provides this structure?

It's an evolutionary development of EDID. Which means there are new EDID blocks defined, which may or may not be transmitted by your display. And if parse-edid or xrandr --props have not already been updated to decode the blocks, you can always download the standard and parse the raw edid hexdump for yourself.

Edit

Here's what I get from my monitor use sudo get-edid | hexdump -C

00000000  00 ff ff ff ff ff ff 00  10 ac 7a a0 4c 41 39 32  |..........z.LA92|
00000010  33 16 01 03 80 34 20 78  ea ee 95 a3 54 4c 99 26  |3....4 x....TL.&|
00000020  0f 50 54 a1 08 00 81 40  81 80 a9 40 b3 00 d1 c0  |.PT....@...@....|
00000030  01 01 01 01 01 01 28 3c  80 a0 70 b0 23 40 30 20  |......(<..p.#@0 |
00000040  36 00 06 44 21 00 00 1a  00 00 00 ff 00 30 46 46  |6..D!........0FF|
00000050  58 44 32 43 49 32 39 41  4c 0a 00 00 00 fc 00 44  |XD2CI29AL......D|
00000060  45 4c 4c 20 55 32 34 31  32 4d 0a 20 00 00 00 fd  |ELL U2412M. ....|
00000070  00 32 3d 1e 53 11 00 0a  20 20 20 20 20 20 00 2c  |.2=.S...      .,|

As you can see that's a single 128 byte block, and it matches the EDID 1.3 format as described on Wikipedia.

If your raw EDID is longer, then it will include additional information, possibly data provided by DisplayId. If it's just this single 128 byte block, it won't.

BTW, I just looked at VESA Standards page, and as a non-member it will cost you $350 to obtain the standard. And so it will everyone else who wants to provide a program to parse this information. So if you are that curious to decode your EDID data ...

dirkt
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  • I've just bought a 2017 model TV, so I was expecting it would use the latest standards to report its capabilities. Of course, the manual doesn't even mention EDID, much less DisplayID, and I don't expect manufacturers will catch up to the information hunger of consumers anytime soon. – l0b0 Apr 14 '17 at 17:12
  • Then parse the raw EDID dump, and find out. If you are really ambitious, submit a patch to `parse-edid` if you find anything. – dirkt Apr 14 '17 at 18:05
  • Do you mean the EDID dump should say whether it somehow provides DisplayID? I'm pretty new at all this… – l0b0 Apr 14 '17 at 21:29