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In the registry there is one (or more) key depending how many monitors you have HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\DISPLAY\DEL404C{Some Unique ID}\Device Parameters\EDID which is a REG_BINARY key. In my case this is :

00 ff ff ff ff ff ff 00 4c 2d 6f 03 39 31 59 4d 
07 12 01 03 0e 29 1a 78 2a 80 c5 a6 57 49 9b 23 
12 50 54 bf ef 80 95 00 95 0f 81 80 81 40 71 4f 
01 01 01 01 01 01 9a 29 a0 d0 51 84 22 30 50 98 
36 00 ac ff 10 00 00 1c 00 00 00 fd 00 38 4b 1e 
51 0e 00 0a 20 20 20 20 20 20 00 00 00 fc 00 53 
79 6e 63 4d 61 73 74 65 72 0a 20 20 00 00 00 ff 
00 48 56 44 51 32 30 36 37 37 37 0a 20 20 00 ef

My question is how can I read only model of monitor ("SyncMaster" for example) and not all of the information using C or C++?

The format of EDID is described here: http://en.wikipedia.org/wiki/Extended_display_identification_data

johnsyweb
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Andrey
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  • The question here is basically how to parse the EDID, not just how to get it. –  Apr 21 '12 at 02:58
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    Dude - you've got the whole spec. Including the offsets of the Mfg ID, model ID, and textual description. What *else* do you need??? – paulsm4 Apr 21 '12 at 03:01
  • I need to know how to do that in C++ – Andrey Apr 21 '12 at 03:08
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    With which part of the C++ implementation did you struggle [when you tried for yourself](http://www.writemycode.net/)? – johnsyweb Apr 21 '12 at 03:12

1 Answers1

5

What you're interested in here is the descriptor blocks of the EDID, which are found in the byte ranges 54-71, 72-89, 90-107, and 108-125. Here's those four blocks in your EDID:

#1: 9a29 a0d0 5184 2230 5098 3600 acff 1000 00
#2: 0000 00fd 0038 4b1e 510e 000a 2020 2020 20
#3: 0000 00fc 0053 796e 634d 6173 7465 720a 20
#4: 0000 00ff 0048 5644 5132 3036 3737 370a 00

You can identify the descriptor containing the monitor name because the first three bytes are all zero (so it isn't a detailed timing descriptor), and the fourth one byte FC (indicating the type). The fifth byte and beyond contain the name, which is here:

5379 6e63 4d61 7374 6572 0a20    SyncMaster..

So, in short: Check at offsets 54, 72, 90, and 108 for the sequence 00 00 00 FC; if you find a match, the monitor name is the next 12 bytes.

  • Note: Model can some times be after FE instead of FC. Ex: Legacy (2019) panel I'm working with used FE (Unspecified text) at the 90 offset, while it's EOL replacement (2021) utilizes FC at the 180 offset. Same manufacturer. – TheHairyOne Jul 20 '23 at 19:23