ejdyksen · August 16, 2025 02:44 · cooltig · Jul 13, 2023 · apassiou · Oct 12, 2023
diff --git a/patch-edid.md b/patch-edid.md
diff --git a/patch-edid.rb b/patch-edid.rb
 #!/usr/bin/ruby
 # Create display override file to force Mac OS X to use RGB mode for Display
 # see http://embdev.net/topic/284710
 # 
 # Update 2013-06-24: added -w0 option to prevent truncated lines

 require 'base64'

 data=`ioreg -l -w0 -d0 -r -c AppleDisplay`

 edid_hex=data.match(/IODisplayEDID.*?<([a-z0-9]+)>/i)[1]
 vendorid=data.match(/DisplayVendorID.*?([0-9]+)/i)[1].to_i
 productid=data.match(/DisplayProductID.*?([0-9]+)/i)[1].to_i

 puts "found display: vendorid #{vendorid}, productid #{productid}, EDID:\n#{edid_hex}"

 bytes=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" % vendorid) rescue nil
 f = File.open("DisplayVendorID-%x/DisplayProductID-%x" % [vendorid, productid], '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>Display with forced RGB mode (EDID override)</string>
  <key>IODisplayEDID</key>
  <data>#{Base64.encode64(bytes.pack('C*'))}</data>
  <key>DisplayVendorID</key>
  <integer>#{vendorid}</integer>
  <key>DisplayProductID</key>
  <integer>#{productid}</integer>
 </dict>
 </plist>"
 f.close
	#!/usr/bin/ruby
	# Create display override file to force Mac OS X to use RGB mode for Display
	# see http://embdev.net/topic/284710
	#
	# Update 2013-06-24: added -w0 option to prevent truncated lines

	require 'base64'

	data=`ioreg -l -w0 -d0 -r -c AppleDisplay`

	edid_hex=data.match(/IODisplayEDID.*?<([a-z0-9]+)>/i)[1]
	vendorid=data.match(/DisplayVendorID.*?([0-9]+)/i)[1].to_i
	productid=data.match(/DisplayProductID.*?([0-9]+)/i)[1].to_i

	puts "found display: vendorid #{vendorid}, productid #{productid}, EDID:\n#{edid_hex}"

	bytes=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" % vendorid) rescue nil
	f = File.open("DisplayVendorID-%x/DisplayProductID-%x" % [vendorid, productid], '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>Display with forced RGB mode (EDID override)</string>
	<key>IODisplayEDID</key>
	<data>#{Base64.encode64(bytes.pack('C*'))}</data>
	<key>DisplayVendorID</key>
	<integer>#{vendorid}</integer>
	<key>DisplayProductID</key>
	<integer>#{productid}</integer>
	</dict>
	</plist>"
	f.close