Skip to content

Instantly share code, notes, and snippets.

@adaugherity
Forked from BugRoger/patch-edid.rb
Last active December 2, 2024 10:07
Show Gist options
  • Save adaugherity/7435890 to your computer and use it in GitHub Desktop.
Save adaugherity/7435890 to your computer and use it in GitHub Desktop.
#!/usr/bin/ruby
# Create display override file to force Mac OS X to use RGB mode for Display
# see http://embdev.net/topic/284710
require 'base64'
data=`ioreg -l -d0 -w 0 -r -c AppleDisplay`
edids=data.scan(/IODisplayEDID.*?<([a-z0-9]+)>/i).flatten
vendorids=data.scan(/DisplayVendorID.*?([0-9]+)/i).flatten
productids=data.scan(/DisplayProductID.*?([0-9]+)/i).flatten
displays = []
edids.each_with_index do |edid, i|
disp = { "edid_hex"=>edid, "vendorid"=>vendorids[i].to_i, "productid"=>productids[i].to_i }
displays.push(disp)
end
# Process all displays
if displays.length > 1
puts "Found %d displays! You should only install the override file for the one which" % displays.length
puts "is giving you problems.","\n"
elsif displays.length == 0
puts "No display data found! Are any external displays connected?"
puts "\nNote: Apple Silicon (arm64) devices are currently unsupported, as the standard"
puts "method of retrieving display information does not work."
end
displays.each do |disp|
# Retrieve monitor model from EDID display descriptor
i = disp["edid_hex"].index('000000fc00')
if i.nil?
monitor_name = "Display"
else
# The monitor name is stored in (up to) 13 bytes of text following 00 00 00 fc 00.
# If the name is shorter than 13 bytes, it is terminated with a newline (0a) and then padded with spaces.
monitor_name = [disp["edid_hex"][i + 10, 26].to_s].pack("H*")
monitor_name.rstrip! # remove trailing newline/spaces
end
puts "Found display '#{monitor_name}': vendor ID=#{disp["vendorid"]} (0x%x), product ID=#{disp["productid"]} (0x%x)" %
[disp["vendorid"], disp["productid"]]
puts "Raw EDID data:\n#{disp["edid_hex"]}"
bytes=disp["edid_hex"].scan(/../).map{|x|Integer("0x#{x}")}.flatten
puts "Setting color support to RGB 4:4:4 only"
bytes[24] &= ~(0b11000)
puts "Number of extension blocks: #{bytes[126]}"
puts "removing extension block"
bytes = bytes[0..127]
bytes[126] = 0
bytes[127] = (0x100-(bytes[0..126].reduce(:+) % 256)) % 256
puts
puts "Recalculated checksum: 0x%x" % bytes[127]
puts "new EDID:\n#{bytes.map{|b|"%02X"%b}.join}"
Dir.mkdir("DisplayVendorID-%x" % disp["vendorid"]) rescue nil
filename = "DisplayVendorID-%x/DisplayProductID-%x" % [disp["vendorid"], disp["productid"]]
puts "Output file: #{Dir.pwd}/#{filename}"
f = File.open(filename, 'w')
f.write '<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">'
f.write "
<dict>
<key>DisplayProductName</key>
<string>#{monitor_name} - forced RGB mode (EDID override)</string>
<key>IODisplayEDID</key>
<data>#{Base64.encode64(bytes.pack('C*'))}</data>
<key>DisplayVendorID</key>
<integer>#{disp["vendorid"]}</integer>
<key>DisplayProductID</key>
<integer>#{disp["productid"]}</integer>
</dict>
</plist>"
f.close
puts "\n"
end # displays.each
@GetVladimir
Copy link

@daili0802 that is actually a good find with the workaround you're using.

I don't know of another way to consistently work except for using the separate cables without using a dock. If you find some solution for this, let us know

@daili0802
Copy link

Sure. @GetVladimir
But, are there ways to us this script to override the EDID without changing the RGB setting?

@GetVladimir
Copy link

@daili0802 as far as I know, this specific script only works for x86 based Macs

@daili0802
Copy link

Ah! that was one important part I missed. Sorry and thank you.

@GetVladimir
Copy link

@daili0802 not a problem, you're welcome. It would be great if it gets resolved

@rainyskye
Copy link

Is there any similar way to accomplish this on an Apple Silicon Mac? Thanks :)

@GetVladimir
Copy link

@apassiou
Copy link

Here is my issue, I am sending signal from Mac to a monitor via HDbaseT adapter, and I get a display like this: https://i.imgur.com/yO1ArVp.png

Whats strange is if I rotate the picture 90 or 180 degrees it looks completely perfect. But setting it back to Standard it goes back looking like the picture. I tried running this script, but it didnt improve it.

@anbarae
Copy link

anbarae commented Oct 14, 2023

I have a 4k monitor, using a MacBook Pro 13-inch, 2017, Two Thunderbolt 3 ports. Resolution is maxed out at blurry 1440p. Any way to fix this?

@joevt
Copy link

joevt commented Oct 15, 2023

@anbarae What display? Is it HDMI or DisplayPort connection? Try SwitchResX? Run AllRez to get a list of display modes.

@brunodantas
Copy link

Works for Sonoma on a 2016 Macbook Pro 👌

@anbarae
Copy link

anbarae commented Oct 25, 2023 via email

@heshaam-42c
Copy link

I have 2 external HDMI-to-usbc monitors. The override works and I can see it take effect in Settings > Displays, but when i rearrange the monitors in Display settings, one of the monitors gets blurry again. Anyone run into this?

@MikaelDDavidd
Copy link

MikaelDDavidd commented Jul 22, 2024

Captura de Tela 2024-07-22 às 00 09 37

Well I tried it in my M1 pro ti try to make de external monitor colors look better, and now my macbook screens says it is 1512 x 982 resolution, and if i try to increase it does not look good, also I lost some screen opions for the same macbook screen, and I just runned the script. Y can check in the imagems the light theme shows how it used to be and the dark how it is now.

@GetVladimir
Copy link

@MikaelDDavidd This solution works on x86 based Macs. It's not meant for M1 based Macs, as they ignore the EDID override.

You can delete the override file you have created, reboot and it should be back to default.

If possible, try using an USB-C to DisplayPort port cable on the M1 Pro

@flawnn
Copy link

flawnn commented Sep 24, 2024

Any way to make this work with BetterDisplay? It also works on Silicon-based Macs.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment