A set of shell functions used to view and edit EDIDs.

EDIDUtil.sh

#!/bin/bash
#!/bin/zsh
# by joevt May 24/2023

#=========================================================================================

edid_decode=edid-decode

#=========================================================================================
# Modify EDID

getarrstart () {
	# bash arrays start at 0
	# zsh arrays start at 1 (applies only to [] syntax) but this can be changed with "setopt ksh_arrays"
	# zsh arrays start at 0 when using ${arr:x:x} syntax
	local arr=(1 0)
	arrstart=${arr[1]}
}
getarrstart


if ((0)); then
        # to clear errors in ShellCheck

        debug=1
        dodump=1

        afterdetailedblockoffset=0

        doclearserialnumber=0
        docleardate=0
        do8bpc=0
        doRGB=0
        do422=0
        dosetpreferredisnative=0
        doclearchromaticity=0
        doclearestablishedtimings=0
        doclearmanufacturerstimings=0
        doclearstandardtimings=0
        patches=()
fi

replacebytes () {
	local bytepos=$(($1*2))
	local thebytes=$2
	local thelen=${#thebytes}
	[[ -n $3 ]] && thelen=$(($3*2))
	theedid=${theedid:0:$bytepos}${thebytes}${theedid:$bytepos+thelen}
}


repairchecksums () {
	local blockoffset=0
	while (( blockoffset*2 < ${#theedid} )); do
		local blocktag=${theedid:$blockoffset*2:2}
		if [[ $blocktag = 70 ]]; then
			local sectionsize=$((0x${theedid:$blockoffset*2+4:2}))
			replacebytes $((blockoffset+sectionsize+5)) "$(printf "%02x" $(( -($(echo -n "${theedid:$blockoffset*2+2:$sectionsize*2+8}" | sed "s/../+0x&/g")) & 0xff )))"
		fi
		replacebytes $((blockoffset+127)) "$(printf "%02x" $(( -($(echo -n "${theedid:$blockoffset*2:254}" | sed "s/../+0x&/g")) & 0xff )))"
		((blockoffset+=128))
	done
}


deleteextensionblock () {
	local blockoffset=$(($1*128))
	if  (( blockoffset*2 < ${#theedid} )); then
	
		(( debug )) && echo ": deleteextensionblock $blockoffset" 1>&2
	
		replacebytes $blockoffset "" 128
		replacebytes 126 "$(printf "%02x" $((0x${theedid:252:2}-1)))"
		processedid
		repairchecksums
	else
		echo "Block at $blockoffset doesn't exist"
	fi
}


deleteextensionblocktype () {
	local blocktype="$1"
	local blockoffset=128
	local blocknum=1
	while (( blockoffset*2 < ${#theedid} )); do
		local blocktag=${theedid:$blockoffset*2:2}
		(( debug )) && echo ": deleteextensionblocktype $blocknum) $blockoffset $blocktag" 1>&2
		if (( 0x$blocktag == blocktype )); then
			deleteextensionblock $blocknum
		else
			((blockoffset+=128))
			((blocknum++))
		fi
	done
}


adddisplayidextensionblock () {
	local version="$1"
	local producttype="$2"
	
	(( debug )) && echo ": adddisplayidextensionblock $version $producttype" 1>&2
	
	#echo adddisplayidextensionblock $version $producttype
	replacebytes 126 "$(printf "%02x" $((0x${theedid:252:2}+1)))"
	theedid+=$(printf "70%02x79%02x%0248x" $((0x${version//./})) "$producttype" 0)
	repairchecksums
}


addctaextensionblock () {
	local version="$1"
	local YCbCrSupportbyte="$2"
	local offset="$3"
	if [[ -z $YCbCrSupportbyte ]]; then
		YCbCrSupportbyte=4
	fi
	if [[ -z $offset ]]; then
		offset=$((${#theedid} / 2))
	fi

	(( debug )) && echo ": addctaextensionblock $version" 1>&2
	
	#echo addctaextensionblock $version $producttype
	replacebytes 126 "$(printf "%02x" $((0x${theedid:252:2}+1)))"
	
#	theedid=${theedid:0:$offset*2}$(printf "02%02x0400%0248x" $((version)) 0)${theedid:$offset*2}

			#	00 edid tag 02
			#
			#	01 		1	CTA version
			#	02 		2	detailed descriptors offset
			#	03 		3	YCbCrSupportbyte


	theedid=${theedid:0:$offset*2}$(printf "02%02x04%02x%0248x" $((version)) $((YCbCrSupportbyte)) 0)${theedid:$offset*2}
	repairchecksums
}


detailed_block () {
	local detailedblock=$1
	
	# other parameters are optional
	local detailedblockoffset=$2
	local willbereplaced=$3
	local willbedeleted=$4
	[[ -z $willbereplaced ]] && willbereplaced=1 # just output it
	[[ -z $willbedeleted ]] && willbedeleted=1 # just output it
	
	local dodump=$dodump
	
	if (( $# == 1 )); then
		dodump=1
	fi
	
	if [[ ${detailedblock:0:4} = 0000 ]]; then
		case ${detailedblock} in
			000000000000000000000000000000000000) (( dodump )) && printf "Empty" ;;
			000000100000000000000000000000000000) (( dodump )) && printf "Dummy block" ;;
			*)
				case ${detailedblock:6:2} in
					0*) (( dodump )) && printf "Manufacturer-specified data" ;;
					10) (( dodump )) && printf "Dummy block" ;;
					f7) (( dodump )) && printf "Established timings III" ;;
					f8) (( dodump )) && printf "CVT 3-byte timing codes" ;;
					f9) (( dodump )) && printf "Color management data" ;;
					fa) (( dodump )) && printf "More standard timings" ;;
					fb) (( dodump )) && printf "Color point" ;;
					fc) (( dodump )) && printf "Monitor name" ;;
					fd) (( dodump )) && printf "Display range limits" ;;
					fe) (( dodump )) && printf "ASCII string" ;;
					ff) (( dodump )) && printf "Serial number" ;;
					*)  (( dodump )) && printf "Reserved(%s)" "${detailedblock:6:2}" ;;
				esac
				(( dodump )) && printf ": %s" "$detailedblock"
		esac

		case ${detailedblock:6:2} in
			fd)
				local minV=$((((0x${detailedblock:8:2} >> 0) & 1) * 255 + 0x${detailedblock:10:2}))
				local maxV=$((((0x${detailedblock:8:2} >> 1) & 1) * 255 + 0x${detailedblock:12:2}))
				local minH=$((((0x${detailedblock:8:2} >> 2) & 1) * 255 + 0x${detailedblock:14:2}))
				local maxH=$((((0x${detailedblock:8:2} >> 3) & 1) * 255 + 0x${detailedblock:16:2}))
				local maxP=$((0x${detailedblock:18:2} * 10))
				local timingtype="?"
				case $((0x${detailedblock:20:2})) in
					0) timingtype="default GTF" ;;
					1) timingtype="limits only" ;;
					2) timingtype="Secondary GTF" ;;
					4) timingtype="CVT" ;;
					*) timingtype="Reserved($((0x${detailedblock:20:2})))" ;;
				esac
				(( dodump )) && printf " = %d-%dHz %d-%dkHz %dMHz (%s:%s)\n" $minV $maxV $minH $maxH $maxP "$timingtype" "${detailedblock:22}"
				;;

			*)	(( dodump )) && echo
				;;
		esac
	else
		local MHz=00$((0x${detailedblock:2:2}${detailedblock:0:2}))
		local hmm=$((0x${detailedblock:28:1}${detailedblock:24:2}))
		local vmm=$((0x${detailedblock:29:1}${detailedblock:26:2}))
		local hactive=$((0x${detailedblock:8:1}${detailedblock:4:2}))
		local hfront=$((((0x${detailedblock:22:1} >> 2) << 8) + 0x${detailedblock:16:2}))
		local hpulse=$((((0x${detailedblock:22:1} & 3) << 8) + 0x${detailedblock:18:2}))
		local hblank=$((0x${detailedblock:9:1}${detailedblock:6:2}))
		local vactive=$((0x${detailedblock:14:1}${detailedblock:10:2}))
		local vfront=$((((0x${detailedblock:23:1} >> 2) << 4) + 0x${detailedblock:20:1}))
		local vpulse=$((((0x${detailedblock:23:1} & 3) << 4) + 0x${detailedblock:21:1}))
		local vblank=$((0x${detailedblock:15:1}${detailedblock:12:2}))
		local hborder=$((0x${detailedblock:30:2}))
		local vborder=$((0x${detailedblock:32:2}))
		local hsync='-'
		local vsync='-'
		local interlaced=''
		local hback=$((hblank - hfront - hpulse))
		local vback=$((vblank - vfront - vpulse))
		(( 0x${detailedblock:34:2} >> 7 )) && interlaced='i'
		(( 0x${detailedblock:34:2} & 2 )) && hsync='+'
		(( 0x${detailedblock:34:2} & 4 )) && vsync='+'

		local kHz='000'
		local Hz='000'
		
		if (( hactive + hblank )); then
			kHz=000$(((10#$MHz * 100000 / (hactive+hblank) + 5)/10))
		fi
		
		if (( (vactive+vblank)*(hactive+hblank) )); then
			Hz=000$(((10#$MHz * 100000000 / ((vactive+vblank)*(hactive+hblank)) + 5)/10))
		fi
		
		local timingstring=""
		timingstring=$(
			printf "%dx%d%s@%d.%sHz %d.%skHz %d.%sMHz  h(%d %d %d %s)  v(%d %d %d %s)" \
				$hactive $vactive "$interlaced" \
				$((10#$Hz/1000)) ${Hz: -3} $((10#$kHz/1000)) ${kHz: -3} $((10#$MHz/100)) ${MHz: -2} \
				$hfront $hpulse $hback "$hsync" \
				$vfront $vpulse $vback "$vsync"
		)

		(( debug )) && echo ":(( $willbereplaced == 0 ))" 1>&2
		
		if (( willbereplaced == 0 && willbedeleted == 0 )); then
			thetimings+=("$timingstring")
			thetimingsoffsets+=("$detailedblockoffset")
			thetimingshex+=("$detailedblock")
		fi

		(( dodump )) && printf "Detailed timing: %s = %s\n" "$detailedblock" "$timingstring"
	fi
}


one_detailed_block () {
	(( debug )) && echo ": one_detailed_block $*" 1>&2
	local detailedblockoffset=$1
	local willbereplaced=$2
	local willbedeleted=$3
	(( dodump )) && echo -n "        ${detailedblockoffset}) "
	detailed_block "${theedid:$detailedblockoffset*2:36}" "$detailedblockoffset" "$willbereplaced" "$willbedeleted"
}


detailed_blocks () {
	(( debug )) && echo ": detailed_blocks $*" 1>&2
	local param=""
	for param in detailedblockoffset afterdetailedblockoffset dodump doreplacedescriptoroffset deletedescriptoroffset replacementdescriptor; do
		(( debug )) && echo ": param $param=$1" 1>&2
		eval "local $param=\"$1\""; shift
	done
	
	(( afterdetailedblockoffset = detailedblockoffset + (afterdetailedblockoffset - detailedblockoffset) / 18 * 18 ))

	if (( detailedblockoffset + 18 <= afterdetailedblockoffset )); then
		(( dodump )) && echo "    Descriptors:"
	
		while (( detailedblockoffset + 18 <= afterdetailedblockoffset )); do
			local willbereplaced=$(( detailedblockoffset == doreplacedescriptoroffset ))
			local willbedeleted=$(( detailedblockoffset == deletedescriptoroffset ))
		
			one_detailed_block "$detailedblockoffset" "$willbereplaced" "$willbedeleted"
			if (( willbereplaced )); then
				replacebytes "$detailedblockoffset" "$replacementdescriptor"
				(( dodump )) && echo "            changed:"
				one_detailed_block "$detailedblockoffset" 0 0
			fi
			if (( willbedeleted )); then
				deletedescriptoroffset=0
				replacebytes "$detailedblockoffset" "${theedid:(detailedblockoffset+18)*2:(afterdetailedblockoffset-detailedblockoffset-18)*2}""$(printf "000000%c00000000000000000000000000000" $((detailedblockoffset < 128)) )"
				(( dodump )) && echo "            changed: deleted"
			else
				((detailedblockoffset+=18))
			fi
		done
	fi
}


colorc () {
	local ccc=$1
	# [0..1023]
	# [0..9990]
	# [10005..19995] add leading zeros (ignore the 1) and rounding
	local rx=$((
				(
					(
						(0x${theedid:54+ccc*2:2} << 2) | ((0x${theedid:50:4} >> (14-ccc*2)) & 3)
					) * 10000 / 1024
				) + 10005
			));
	echo -n 0.${rx:1:3} # output 3 digits (ignoring the leading 1)
}


dumptype1timingdescriptor () {
	local type1timing=$1

	local MHz=00$((0x${type1timing:4:2}${type1timing:2:2}${type1timing:0:2} + 1))

	local preferred=''
	(( 0x${type1timing:6:2} >> 7 )) && preferred=' preferred'

	local support3D=' 3D:undefined'
	case $(( (0x${type1timing:6:2} >> 5) & 3 )) in
		0) support3D='' ;;
		1) support3D=' stereo' ;; 
		2) support3D=' stereo/mono' ;;
		3) support3D=' 3D:reserved' ;;
	esac

	local interlaced=''
	(( (0x${type1timing:6:2} >> 4) & 1 )) && interlaced='i'

	local aspect=' aspect:reserved'
	case $(( 0x${type1timing:6:2} & 15 )) in
		0) aspect=' 1:1' ;;
		1) aspect=' 5:4' ;;
		2) aspect=' 4:3' ;;
		3) aspect=' 15:9' ;;
		4) aspect=' 16:9' ;;
		5) aspect=' 16:10' ;;
		6) aspect=' 64:27' ;;
		7) aspect=' 256:135' ;;
		8) aspect=' aspect:undefined' ;;
	esac

	local hactive=$((0x${type1timing:10:2}${type1timing:8:2} + 1))
	local hblank=$((0x${type1timing:14:2}${type1timing:12:2} + 1))
	local hfront=$(((0x${type1timing:18:2}${type1timing:16:2} & 32767) + 1))
	local hsync='-'
	(( 0x${type1timing:18:2} >> 7 )) && hsync='+'
	local hpulse=$((0x${type1timing:22:2}${type1timing:20:2} + 1))
	local hback=$((hblank - hfront - hpulse))

	local vactive=$((0x${type1timing:26:2}${type1timing:24:2} + 1))
	local vblank=$((0x${type1timing:30:2}${type1timing:28:2} + 1))
	local vfront=$(((0x${type1timing:34:2}${type1timing:32:2} & 32767) + 1))
	local vsync='-'
	(( 0x${type1timing:34:2} >> 7 )) && vsync='+'
	local vpulse=$((0x${type1timing:38:2}${type1timing:36:2} + 1))
	local vback=$((vblank - vfront - vpulse))

	local kHz=000$(((10#$MHz * 100000 / (hactive+hblank) + 5)/10))
	local Hz=000$(((10#$MHz * 100000000 / ((vactive+vblank)*(hactive+hblank)) + 5)/10))

	printf "%dx%d%s@%d.%sHz %d.%skHz %d.%sMHz  h(%d %d %d %s)  v(%d %d %d %s)%s%s%s" \
		$hactive $vactive "$interlaced" \
		$((10#$Hz/1000)) ${Hz: -3} $((10#$kHz/1000)) ${kHz: -3} $((10#$MHz/100)) ${MHz: -2} \
		$hfront $hpulse $hback "$hsync" \
		$vfront $vpulse $vback "$vsync"	\
		"$support3D" "$aspect" "$preferred"
}


dumptileddisplaytopologyblock () {
	local tiledblock=$1
	local revision=$((0x${tiledblock:2:2} & 7)) # high 5 bits should be 0
	local length=$((0x${tiledblock:4:2})) # should be 22
	local capabilities=$((0x${tiledblock:6:2}))
	
	local enclosuretype=$(( (capabilities >> 7) & 1 ))
	local tilebezelinformationdescriptoravailable=$(( (capabilities >> 6) & 1 ))
	# bit 5 reserved
	local behaviorsome=$(( (capabilities >> 3) & 3 ))
	local behavioronly=$(( (capabilities >> 0) & 7 ))
	
	tileCountH=$(( 0x${tiledblock:8:1} + ((0x${tiledblock:12:2} >> 2) & 0x30) + 1 ))
	tileCountV=$(( 0x${tiledblock:9:1} + ((0x${tiledblock:12:2} >> 0) & 0x30) + 1 ))
	local tileLocationH=$(( 0x${tiledblock:10:1} + ((0x${tiledblock:12:2} << 2) & 0x30) ))
	local tileLocationV=$(( 0x${tiledblock:11:1} + ((0x${tiledblock:12:2} << 4) & 0x30) ))
	
	tileSizeH=$(( 0x${tiledblock:16:2}${tiledblock:14:2} + 1 ))
	tileSizeV=$(( 0x${tiledblock:20:2}${tiledblock:18:2} + 1 ))

	# depends on tilebezelinformationdescriptoravailable
	local pixelmultiplier=$(( 0x${tiledblock:22:2} ))
	local bezelsizetop=$(( 0x${tiledblock:24:2} ))
	local bezelsizebottom=$(( 0x${tiledblock:26:2} ))
	local bezelsizeleft=$(( 0x${tiledblock:28:2} ))
	local bezelsizeright=$(( 0x${tiledblock:30:2} ))

        local vendorid=""
	vendorid=$(echo -n "${tiledblock:32:6}" | xxd -p -r)
	local productid=$((0x${tiledblock:40:2}${tiledblock:38:2}))
	local serialnumber=$((0x${tiledblock:48:2}${tiledblock:46:2}${tiledblock:44:2}${tiledblock:42:2}))

	if (( dodump )); then
		printf "%dx%d @ (%d,%d) of (%dx%d) vendor:%s product:0x%04x serial:%d" \
		$tileSizeH $tileSizeV \
		$tileLocationH $tileLocationV \
		$tileCountH $tileCountV \
		"$vendorid" $productid $serialnumber
	
		printf ' enclosure:'
		case $enclosuretype in
			0) printf 'multiple' ;;
			1) printf 'single' ;;
		esac

		printf ' some:'
		case $behaviorsome in
			0) printf 'undescribed' ;;
			1) printf 'location' ;;
			*) printf 'reserved%s' $behaviorsome ;;
		esac
	
		printf ' one:'
		case $behavioronly in
			0) printf 'undescribed' ;;
			1) printf 'location' ;;
			2) printf 'scaled' ;;
			3) printf 'cloned' ;;
			*) printf 'reserved%s' $behavioronly ;;
		esac
	
		if (( tilebezelinformationdescriptoravailable )); then
			printf " bezel(t,l,b,r):(%d,%d,%d,%d)x%d" \
			$bezelsizetop \
			$bezelsizeleft \
			$bezelsizebottom \
			$bezelsizeright \
			$pixelmultiplier
		fi
	fi
}


flagsstring () {
	local label=$1
	local bitfirst=$2
	local bitlast=$3
	local bitdirection=1
	local theflags="$4"
	local result=""
	if [[ -z $theflags ]]; then
		result="missing"
	else
		shift 4
		theflags=$((0x$theflags))
		(( bitlast < bitfirst )) && bitdirection=-1
		result=""
		local thebit=$bitfirst
		while (( 1 )); do
			if (( theflags & (2 ** thebit) )); then
				[[ -n $result ]] && result+=","
				[[ -z $1 ]] && result+="reserved$thebit" || result+="$1"
			fi
			(( $# )) && shift
			(( thebit == bitlast )) && break
			(( thebit = thebit + bitdirection ))
		done
	fi
	[[ -n $result ]] && echo -n " $label:$result"
}


dumpdisplayinterfacefeaturesdata () {
	local theblock=$1
	local revision=$((0x${theblock:2:2} & 7)) # high 5 bits should be 0
	local length=$((0x${theblock:4:2})) # should be 9+N
	local colorDepthsRGB=""
	local colorDepthsYCbCr444=""
	local colorDepthsYCbCr422=""
	local colorDepthsYCbCr420=""
	local audio=""
	local colorspace_eotf_combinations1=""
	local colorspace_eotf_combinations2=""
	colorDepthsRGB=$(flagsstring "RGB" 0 7 "${theblock:6:2}" 6 8 10 12 14 16)
	colorDepthsYCbCr444=$(flagsstring "444" 0 7 "${theblock:8:2}" 6 8 10 12 14 16)
	colorDepthsYCbCr422=$(flagsstring "422" 0 7 "${theblock:10:2}" 8 10 12 14 16)
	colorDepthsYCbCr420=$(flagsstring "420" 0 7 "${theblock:12:2}" 8 10 12 14 16)
	local minRateYCbCr420string=" 420(MHz):missing"
	if [[ -n ${theblock:14:2} ]]; then
		local minRateYCbCr420=$((0x${theblock:14:2} * 7425)) # / 100
		(( minRateYCbCr420 > 0 )) && minRateYCbCr420string=" 420:≥$(( minRateYCbCr420/100 )).${minRateYCbCr420: -2}MHz" || minRateYCbCr420string=""
	fi
	audio=$(flagsstring "audio(kHz)" 7 0 "${theblock:16:2}" "32" "44.1" "48")
	colorspace_eotf_combinations1=$(flagsstring "colorspace/eotf#1" 0 7 "${theblock:18:2}" \
		"sRGB" \
		"BT.601" \
		"BT.709/BT.1886" \
		"Adobe RGB" \
		"DCI-P3" \
		"BT.2020" \
		"BT.2020/SMPTE ST 2084")
	colorspace_eotf_combinations2=$(flagsstring "colorspace/eotf#2" 0 7 "${theblock:20:2}")
	
	local additional_colorspace_eotf="missing"
	if [[ -n ${theblock:22:2} ]]; then
		local num_additional_colorspace_eotf=$((0x${theblock:22:2} & 7))
		additional_colorspace_eotf=""

		local cendx=""
		for (( cendx = 0; cendx < num_additional_colorspace_eotf; cendx++ )); do
			(( cendx > 0 )) && additional_colorspace_eotf+=","
			local colorspace=""
			local eotf=""
			if [[ -z ${theblock:24+$cendx*2:2} ]]; then
				additional_colorspace_eotf+="missing"
			else
				case $((0x${theblock:24+$cendx*2:2} >> 4)) in
					0) colorspace="Undefined" ;;
					1) colorspace="sRGB" ;;
					2) colorspace="BT.601" ;;
					3) colorspace="BT.709" ;;
					4) colorspace="Adobe RGB" ;;
					5) colorspace="DCI-P3" ;;
					6) colorspace="BT.2020" ;;
					7) colorspace="Custom" ;;
					*) colorspace="Reserved$((0x${theblock:24+$cendx*2:2} >> 4))" ;;
				esac

				case $((0x${theblock:24+$cendx*2:2} & 15)) in
					0)  eotf="Undefined" ;;
					1)  eotf="sRGB" ;;
					2)  eotf="BT.601" ;;
					3)  eotf="BT.1886" ;;
					4)  eotf="Adobe RGB" ;;
					5)  eotf="DCI-P3" ;;
					6)  eotf="BT.2020" ;;
					7)  eotf="Gamma function" ;;
					8)  eotf="SMPTE ST 2084" ;;
					9)  eotf="Hybrid Log" ;;
					10) eotf="Custom" ;;
					*)  eotf="Reserved$((0x${theblock:24+$cendx*2:2} & 15))" ;;
				esac
				[[ $colorspace = "$eotf" ]] && additional_colorspace_eotf+="$colorspace" || additional_colorspace_eotf+="$colorspace/$eotf"
			fi
		done
	fi
	local lengtherror=""
	(( length != 9 + num_additional_colorspace_eotf )) && lengtherror+=" ($length != $((9 + num_additional_colorspace_eotf)))"

	[[ -n $additional_colorspace_eotf ]] && additional_colorspace_eotf=" colorspace/eotf#n:$additional_colorspace_eotf"
	if (( dodump )); then
		printf "revision:%d%s%s%s%s%s%s%s%s%s%s" \
			$revision \
			"$colorDepthsRGB" \
			"$colorDepthsYCbCr444" \
			"$colorDepthsYCbCr422" \
			"$colorDepthsYCbCr420" \
			"$minRateYCbCr420string" \
			"$audio" \
			"$colorspace_eotf_combinations1" \
			"$colorspace_eotf_combinations2" \
			"$additional_colorspace_eotf" \
			"$lengtherror"
	fi
}


processedid () {
	(( debug )) && echo ": processedid $*" 1>&2

	local ctablocktypetodelete=":"
	local newctablocks=()
	local currentnewctablock=0

	local newctadescriptors=()
	local currentnewctadescriptor=0

	local displayidblocktypetodelete=9999
	local newdisplayidblocks=()
	local currentnewdisplayidblock=0

	while (( $# )); do
		local param="$1"; shift
		eval "local $param=1"
		case "$param" in
			doreplacedescriptor)
				local doreplacedescriptoroffset="$1"; shift
				local replacementdescriptor="$1"; shift ;;

			doaddctablock)
				local doaddctablockoffset="$1"; shift
				if (( doaddctablockoffset == 0 )); then
					doaddctablockoffset=$EndOfLastctablock
				fi
				(( debug )) && echo ": doaddctablock $doaddctablockoffset" 1>&2
				while (( $# )); do
					(( debug )) && echo ": doaddctablock param: $1" 1>&2
					newctablocks+=("$1"); shift
				done
				;;
			dodeletectablock)
				local deletectablockoffset="$1"; shift ;;
			dodeletectablocktype)
				while [[ "$1" =~ [0-9a-f]+ ]]; do
					ctablocktypetodelete="${ctablocktypetodelete}$1:"; shift
				done
				;;

			doaddctadescriptor)
				local doaddctadescriptoroffset="$1"; shift
				if (( doaddctadescriptoroffset == 0 )); then
					doaddctadescriptoroffset=$EndOfLastctadescriptor
				fi
				(( debug )) && echo ": doaddctadescriptor $doaddctadescriptoroffset" 1>&2
				while (( $# )); do
					(( debug )) && echo ": doaddctadescriptor param: $1" 1>&2
					newctadescriptors+=("$1"); shift
				done
				;;
			dodeletedescriptor)
				local deletedescriptoroffset="$1"; shift ;;

			doadddisplayidblock)
				local doadddisplayidblockoffset="$1"; shift
				if (( doadddisplayidblockoffset == 0 )); then
					doadddisplayidblockoffset=$EndOfLastDisplayIDblock
				fi
				(( debug )) && echo ": doadddisplayidblock $doadddisplayidblockoffset" 1>&2
				while (( $# )); do
					(( debug )) && echo ": doadddisplayidblock param: $1" 1>&2
					newdisplayidblocks+=("$1"); shift
				done
				;;
			dodeletedisplayidblock)
				local deletedisplayidblockoffset="$1"; shift ;;
			dodeletedisplayidblockblocktype)
				local displayidblocktypetodelete="$1"; shift ;;

			dosetpreferredisnative)
				preferredvalue="$1"; shift ;;
		esac
	done

	# Remember the end of the last CTA block (-1 means no CTA blocks exist.
	# It is also used by addctablock for inserting new CTA blocks at the first available location.
	EndOfLastctablock=-1
	# Keep a list of found CTA blocks.
	ctablocks=()

	# Remember the end of the last CTA descriptor block (-1 means no CTA blocks exist.
	# It is also used by addctadescriptor for inserting new CTA blocks at the first available location.
	EndOfLastctadescriptor=-1
	# Keep a list of found CTA blocks.
	ctadescriptors=()

	# Remember the end of the last DisplayID block (-1 means no DisplayID blocks exist.
	# It is also used by adddisplayidblock for inserting new DisplayID blocks at the first available location.
	EndOfLastDisplayIDblock=-1
	# Keep a list of found DisplayID blocks.
	DisplayIDblocks=()

	# Keep a list of found timings and their offsets.
	thetimings=()
	thetimingsoffsets=()
	thetimingshex=()
	
	HasAudio=0
	HasTile=0

	(( debug )) && echo ": parse 1" 1>&2
	theproductid=$((0x${theedid:22:2}${theedid:20:2}))
	thevendorid=$((0x${theedid:16:4}))
	(( debug )) && echo ": parse 2" 1>&2
	thevendorcode="$(printf "%06x" $((((thevendorid&0x7c00)<<6)+((thevendorid&0x3e0)<<3)+(thevendorid&0x1f)+0x404040)) | xxd -p -r)"
	(( debug )) && echo ": parse 2.1" 1>&2
	theweekofmanufacture=$((0x${theedid:32:2}))
	(( debug )) && echo ": parse 2.2" 1>&2
	theyearofmanufacture=$((0x${theedid:34:2}+1990))
	(( debug )) && echo ": parse 3" 1>&2
	thevendordir="DisplayVendorID-$(printf "%x" $thevendorid)"
	theproductfile="${thevendordir}/DisplayProductID-$(printf "%x" $theproductid)"
	themanufacturefile="${thevendordir}/DisplayYearManufacture-$theyearofmanufacture-DisplayWeekManufacture-$theweekofmanufacture"
	thefilenamebase="$(printf "EDID_%s_%x_%x" "$thevendorcode" $thevendorid $theproductid)"

	(( debug )) && echo ": parse 4" 1>&2
	theEDIDversion=$((0x${theedid:0x12*2:2})).$((0x${theedid:0x13*2:2})) # 1.3 or 1.4
	isdigital=$(( 0x${theedid:0x14*2:1} > 7 )) # 0 or 1
	colordepth=$(( 0x${theedid:0x14*2:1} & 7 ))
	featuresupportbyte=$((0x${theedid:0x18*2:2}))
	featuresupport=$(( (featuresupportbyte >> 3) & 3 ))
	preferredisnative=$(( (featuresupportbyte >> 1) & 1 ))
	iscontinuous=$(( (featuresupportbyte >> 0) & 1 ))

	(( dodump )) && echo "0) EDID $theEDIDversion"
	
	(( dodump )) && printf "    Vendor ID: %s %d = 0x%x\n" "$thevendorcode" $thevendorid $thevendorid
	(( dodump )) && printf "    Product ID: %d = 0x%x\n" $theproductid $theproductid

	if [[ ${theedid:24:8} != 00000000 ]]; then
		(( dodump )) && printf "    Serial Number: %d" $((0x${theedid:30:2}${theedid:28:2}${theedid:26:2}${theedid:24:2}))
		if (( doclearserialnumber )); then
			replacebytes 12 00000000
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi

	if [[ ${theedid:32:4} != 0000 ]]; then
		if (( dodump )); then
			case ${theedid:32:4} in
				00*) printf "    Made in year %s" "$theyearofmanufacture" ;;
				ff*) printf "    Model year: %s" "$theyearofmanufacture" ;;
				  *) printf "    Made in week %s of %s" "$theweekofmanufacture" "$theyearofmanufacture"
			esac
		fi
		if (( docleardate )); then
			replacebytes 16 0000
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi

	(( dodump )) && printf "    "
	if [[ " $theEDIDversion" < " 1.4" ]]; then
		(( dodump )) &&
			case $featuresupport in
				0) echo "Monochrome or Grayscale" ;;
				1) echo "RGB color" ;;
				2) echo "Non-RGB color" ;;
				3) echo "Undefined" ;;
			esac
	else
		(( dodump )) &&
			case $isdigital$featuresupport in
				00) echo "Monochrome or Grayscale" ;;
				01) echo "RGB color" ;;
				02) echo "Non-RGB color" ;;
				03) echo "Undefined" ;;
				10) printf "RGB 4:4:4" ;;
				11) printf "RGB 4:4:4, YCrCb 4:4:4" ;;
				12) printf "RGB 4:4:4, YCrCb 4:2:2" ;;
				13) printf "RGB 4:4:4, YCrCb 4:4:4, YCrCb 4:2:2" ;;
			esac

		if (( isdigital )); then
			(( dodump )) &&
				case $colordepth in
					0) echo "; undefined bpc" ;;
					1) echo "; 6 bpc" ;;
					2) echo "; 8 bpc" ;;
					3) echo "; 10 bpc" ;;
					4) echo "; 12 bpc" ;;
					5) echo "; 14 bpc" ;;
					6) echo "; 16 bpc" ;;
					7) echo "; 18 bpc error" ;;
				esac
			if (( do8bpc )); then
				replacebytes 20 "$(printf "%02x" $(((0x${theedid:0x14*2:2} & ~0x70) | 0x20)))"
				(( dodump )) && echo '        changed: 8 bpc'
			fi
		fi
		
		if (( doRGB )); then
			local newfeaturesupportbyte=$(((featuresupportbyte & ~0x18) | (0 << 3) ))
			replacebytes 24 "$(printf "%02x" $newfeaturesupportbyte)"
			(( dodump )) &&
				case $isdigital in
					0) echo '        changed: Monochrome or Grayscale' ;;
					1) echo '        changed: RGB 4:4:4' ;;
				esac
		fi

		if (( do422 )); then
			local newfeaturesupportbyte=$(((featuresupportbyte & ~0x18) | (3 << 3) ))
			replacebytes 24 "$(printf "%02x" $newfeaturesupportbyte)"
			(( dodump )) &&
				case $isdigital in
					0) echo '        changed: Undefined' ;;
					1) echo '        changed: RGB 4:4:4, YCrCb 4:4:4, YCrCb 4:2:2' ;;
				esac
		fi
	fi

	(( dodump )) &&
		case $preferredisnative in
			1) echo "    Preferred Timing Mode is native pixel format and preferred refresh rate" ;;
		esac
		
	if (( dosetpreferredisnative && (preferredvalue != preferredisnative) )); then
		local newfeaturesupportbyte=$(((featuresupportbyte & ~2) | (preferredvalue << 1) ))
		replacebytes 24 "$(printf "%02x" $newfeaturesupportbyte)"
		(( dodump )) && echo '        changed'
	fi
	
	(( dodump )) &&
		case $iscontinuous in
			0) echo "    Display is non-continuous frequency" ;;
			1) echo "    Display is continuous frequency" ;;
		esac

	if [[ ${theedid:50:20} != 00000000000000000000 ]]; then
		(( dodump )) && printf "    Color characteristics: R(%s,%s) G(%s,%s) B(%s,%s) W(%s,%s)" "$(colorc 0)" "$(colorc 1)" "$(colorc 2)" "$(colorc 3)" "$(colorc 4)" "$(colorc 5)" "$(colorc 6)" "$(colorc 7)"
		if (( doclearchromaticity )); then
			replacebytes 25 00000000000000000000
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi

	if [[ ${theedid:70:4} != 0000 ]]; then
		(( dodump )) && printf "    Established timings: %s" "${theedid:70:4}"
		if (( doclearestablishedtimings )); then
			replacebytes 35 0000
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi

	if [[ ${theedid:74:2} != 00 ]]; then
		(( dodump )) && printf "    Manufacturer's timings: %s" "${theedid:74:2}"
		if (( doclearmanufacturerstimings )); then
			replacebytes 37 00
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi

	if [[ ${theedid:76:32} != 01010101010101010101010101010101 ]]; then
		(( dodump )) && printf "    Standard timings: %s" "${theedid:76:32}"
		if (( doclearstandardtimings )); then
			replacebytes 38 01010101010101010101010101010101
			(( dodump )) && printf " changed: unspecified"
		fi
		(( dodump )) && echo
	fi
	
	detailed_blocks 54 126 "$dodump" "$doreplacedescriptoroffset" "$deletedescriptoroffset" "$replacementdescriptor"
	
	local blockoffset=128
	while (( blockoffset*2 < ${#theedid} )); do

		(( debug )) && echo ": extension block $blockoffset" 1>&2
		local theblock=${theedid:$blockoffset*2:254}
		(( debug )) && echo ": extension theblock = $theblock" 1>&2
		local blocktag=${theblock:0:2}
		(( debug )) && echo ": blocktag = $blocktag" 1>&2
		if [[ $blocktag = 02 ]]; then
			(( debug )) && echo ": parsing CTA extension block" 1>&2

			#	00 edid tag 02
			#
			#	01 		1	CTA version
			#	02 		2	detailed descriptors offset
			#	03 		3	YCbCrSupportbyte
			#		
			#	04 00 		CTA data block #1 3 bit type (0-7), 5 bit length - 1 (1-32)
			#	05 01 		CTA data block #1 extended tag code if type is 7
			#
			#	detailedTimingDescriptorsOffset 18 byte descriptors
			#
			#	7F EDID checksum

			CTAversion=$((0x${theblock:2:2}))
			(( debug )) && echo ": CTAversion = $CTAversion" 1>&2
			local detailedTimingDescriptorsOffset=$((0x${theblock:4:2}))
			local afterctadescriptorblockoffset=127
			YCbCrSupportbyte=$((0x${theblock:6:2}))
			if (( CTAversion > 1 )); then
				(( dodump )) && echo "$blockoffset) CTA-861 extension block with new version $CTAversion"
				YCbCrSupport=$((( YCbCrSupportbyte >> 4) & 3))
				(( dodump )) &&
					case $YCbCrSupport in
						0) echo "    No YCbCr support" ;;
						1) echo "    YCbCr 4:2:2" ;;
						2) echo "    YCbCr 4:4:4" ;;
						3) echo "    YCbCr 4:4:4, YCbCr 4:2:2" ;;
					esac

				if (( doRGB )); then
					newYCbCrSupportbyte=$(((YCbCrSupportbyte & ~0x30) | (0 << 4) ))
					replacebytes $((blockoffset+3)) "$(printf "%02x" $newYCbCrSupportbyte)"
					(( dodump )) && echo '        changed: No YCbCr support'
				fi

				if (( do422 )); then
					newYCbCrSupportbyte=$(((YCbCrSupportbyte & ~0x30) | (3 << 4) ))
					replacebytes $((blockoffset+3)) "$(printf "%02x" $newYCbCrSupportbyte)"
					(( dodump )) && echo '        changed: YCbCr 4:4:4, YCbCr 4:2:2'
				fi

				BasicAudioSupport=$((( YCbCrSupportbyte >> 6) & 1))
				(( dodump )) &&
					case $BasicAudioSupport in
						1) echo "    Basic audio support" ;;
					esac
			else
				(( dodump )) && echo "$blockoffset) CTA-861 extension block with old version $CTAversion"
			fi

			local newctablock=""
			local lastctablockoffset=0
			local ctablocksAdded=0

			local newctadescriptor=""
			local lastctadescriptoroffset=0
			local ctadescriptorsAdded=0

			if (( CTAversion > 2 )); then
				# Loop CTA blocks
				
				local CTAdatablockoffset=4
				if (( doaddctablockoffset == -1 )); then
					doaddctablockoffset=$((blockoffset + CTAdatablockoffset))
				fi
				
				local overflow=0
				while (( CTAdatablockoffset <= detailedTimingDescriptorsOffset )); do

					if (( blockoffset + CTAdatablockoffset == doaddctablockoffset )); then
						(( debug )) && echo ": found CTA block $doaddctablockoffset" 1>&2
						# concatenate all the new blocks that will fit
						while (( currentnewctablock < ${#newctablocks[@]} )); do
							local CTAdatablock=${newctablocks[currentnewctablock+arrstart]}
							(( debug )) && echo ": testing $CTAdatablock" 1>&2
							if (( ${#CTAdatablock}/2 > 0x7b )); then
								echo "Error: CTA block is too large: ${CTAdatablock}" 1>&2
							else
								if (( 4 + (${#newctablock} + ${#CTAdatablock})/2 > 0x7f )); then
									(( debug )) && echo ": overflow" 1>&2
									overflow=1
									break
								fi
								newctablock+="${CTAdatablock}"
								((ctablocksAdded++))
								(( debug )) && echo ": $ctablocksAdded: concetenate result: $newctablock" 1>&2
							fi
							((currentnewctablock++))
						done
						newctablocks=("${newctablocks[@]:$currentnewctablock}")
						currentnewctablock=0
				
						if (( ctablocksAdded == 0 )); then
							# none fit here, try in the next block
							doaddctablockoffset=-1
						fi
					fi
					
					if (( CTAdatablockoffset >= detailedTimingDescriptorsOffset)); then
						break
					fi

					local CTAdatablocklength=$(((0x${theblock:$CTAdatablockoffset*2:2} & 0x1f) + 1))
					local CTAdatablock=${theblock:$CTAdatablockoffset*2:$CTAdatablocklength * 2}
					
					# blocks that won't fit are inserted into a list that will be added later
					if (( overflow || (4 + ${#newctablock}/2 + CTAdatablocklength > 0x7f) )); then
						overflow=1
						newctablocks+=("$CTAdatablock")
						if ((lastctablockoffset == 0)); then
							lastctablockoffset=$CTAdatablockoffset
						fi
					else
						newctablock+="${CTAdatablock}"
					fi
					((CTAdatablockoffset+=CTAdatablocklength))
				done
				if ((lastctablockoffset == 0)); then
					lastctablockoffset=$CTAdatablockoffset
				fi
			fi # CTAversion > 2

			if ((1)); then
				# Loop CTA descriptors

				local ctadescriptorblockoffset=$((detailedTimingDescriptorsOffset))
				if (( doaddctadescriptoroffset == -1 )); then
					doaddctadescriptoroffset=$((blockoffset + ctadescriptorblockoffset))
				fi

				local overflow=0
				while (( ctadescriptorblockoffset <= afterctadescriptorblockoffset )); do

					if (( blockoffset + ctadescriptorblockoffset == doaddctadescriptoroffset )); then
						(( debug )) && echo ": found CTA descriptor offset $doaddctadescriptoroffset" 1>&2
						# concatenate all the new blocks that will fit
						while (( currentnewctadescriptor < ${#newctadescriptors[@]} )); do
							local ctadescriptor=${newctadescriptors[currentnewctadescriptor+arrstart]}
							(( debug )) && echo ": testing $ctadescriptor" 1>&2
							if (( ${#ctadescriptor}/2 != 18 )); then
								echo "Error: CTA descriptor is wrong size (18 bytes expected): ${ctadescriptor}" 1>&2
							else
								if (( 4 + (${#newctablock} + ${#newctadescriptor} + ${#ctadescriptor})/2 > 0x7f )); then
									(( debug )) && echo ": overflow" 1>&2
									overflow=1
									break
								fi
								newctadescriptor+="${ctadescriptor}"
								((ctadescriptorsAdded++))
								(( debug )) && echo ": $ctadescriptorsAdded: concetenate result: $newctadescriptor" 1>&2
							fi
							((currentnewctadescriptor++))
						done
						newctadescriptors=("${newctadescriptors[@]:$currentnewctadescriptor}")
						currentnewctadescriptor=0
				
						if (( ctadescriptorsAdded == 0 )); then
							# none fit here, try in the next block
							doaddctadescriptoroffset=-1
						fi
					fi
					
					if (( ctadescriptorblockoffset + 18 > afterctadescriptorblockoffset )); then
						break
					fi

					local ctadescriptorlength=18
					local ctadescriptor=${theblock:$ctadescriptorblockoffset*2:$ctadescriptorlength * 2}

					# blocks that won't fit are inserted into a list that will be added later
					if (( overflow || (4 + (${#newctablock} + ${#newctadescriptor})/2 + ctadescriptorlength > 0x7f) )); then
						overflow=1
						case ${ctadescriptor} in
							000000000000000000000000000000000000) ;; # "Empty"
							000000100000000000000000000000000000) ;; # "Dummy block"
							*)
								newctadescriptors+=("$ctadescriptor")
								if ((lastctadescriptoroffset == 0)); then
									lastctadescriptoroffset=$ctadescriptorblockoffset
								fi
								;;
						esac
					else
						newctadescriptor+="${ctadescriptor}"
					fi
					((ctadescriptorblockoffset+=ctadescriptorlength))
				done
				if ((lastctadescriptoroffset == 0)); then
					lastctadescriptoroffset=$ctadescriptorblockoffset
				fi
			fi

			if (( ctablocksAdded || ctadescriptorsAdded )); then
				detailedTimingDescriptorsOffset=$(( 4 + ${#newctablock}/2 ))
				replacebytes $(( 2 + blockoffset )) "$( printf "%02x" "$detailedTimingDescriptorsOffset" )"
				replacebytes $(( 4 + blockoffset )) "${newctablock}${newctadescriptor}$(printf "%0*x" $((0x7b*2 - ${#newctablock} - ${#newctadescriptor})) 0)"
				theblock=${theedid:$blockoffset*2:254}
				if (( ${#newctablocks[@]} > 0 )); then
					doaddctablockoffset=-1
				fi
				if (( ${#newctadescriptors[@]} > 0 )); then
					doaddctadescriptoroffset=-1
				fi
			fi

			if (( CTAversion > 2 )); then
				# Process CTA blocks

				CTAdatablockoffset=4
				(( dodump && (CTAdatablockoffset < detailedTimingDescriptorsOffset) )) && echo "    CTA data blocks:"
				while (( CTAdatablockoffset < detailedTimingDescriptorsOffset )); do

					CTAdatablocklength=$(((0x${theblock:$CTAdatablockoffset*2:2} & 0x1f) + 1))
					CTAdatablock=${theblock:$CTAdatablockoffset*2:$CTAdatablocklength * 2}
					CTAtagcode=$((0x${CTAdatablock:0:2} >> 5))
					if (( CTAtagcode == 7 )); then
						CTAtagcode=$(printf "%x" $((0x${CTAdatablock:2:2} + 0x700)))
					fi

					if (( dodump )); then
						echo -n "        $((blockoffset + CTAdatablockoffset))) "
						case $CTAtagcode in
							0) printf "Reserved" ;;
							1) printf "Audio" ;;
							2) printf "Video" ;;
							3) printf "Vendor-specific" ;;
							4) printf "Speaker allocation" ;;
							5) printf "Display transfer characteristic" ;;
							6) printf "Reserved" ;;

							700) printf "Video capability" ;;
							701) printf "Vendor-specific video" ;;
							702) printf "VESA display device" ;;
							703) printf "VESA video timing block" ;;
							704) printf "Reserved for HDMI video" ;;
							705) printf "Colorimetry" ;;
							706) printf "HDR static metadata" ;;
							707) printf "HDR dynamic metadata" ;;

							70d) printf "Video format preference" ;;
							70e) printf "YCbCr 4:2:0 video" ;;
							70f) printf "YCbCr 4:2:0 capability map" ;;
							710) printf "Reserved for CTA miscellaneous audio fields" ;;
							711) printf "Vendor-specific audio" ;;
							712) printf "Reserved for HDMI audio" ;;
							713) printf "Room configuration" ;;
							714) printf "Speaker location" ;;

							720) printf "InfoFrames" ;;
							
							*)
								if (( 0x$CTAtagcode < 0x70d )); then
									printf "Reserved for video-related"
								elif (( 0x$CTAtagcode < 0x720 )); then
									printf "Reserved for audio-related"
								else
									printf "Reserved"
								fi
								printf " (e%s)" "${CTAtagcode: -2}"
								;;
						esac
						echo -n ": $CTAdatablock"
					fi

					local thepattern=".*:$CTAtagcode:.*"
					local willberemoved=0
					if (( blockoffset + CTAdatablockoffset == deletectablockoffset )); then
						willberemoved=1
						deletectablockoffset=0
					fi
					if [[ $ctablocktypetodelete =~ $thepattern ]]; then
						willberemoved=1
					fi

					case $CTAtagcode in
						1)
							(( dodump )) && echo
							HasAudio=1
							;;
						3)
							IEEEOUI=${CTAdatablock:6:2}${CTAdatablock:4:2}${CTAdatablock:2:2}
							(( dodump )) && echo -n " = $IEEEOUI:"
							case $IEEEOUI in
								000c03)
									(( dodump )) && echo " HDMI Licensing, LLC -> H14b VSDB"
									H14bByte=${CTAdatablock:12:2}
									if [[ -n $H14bByte ]]; then
										H14bByte=$((0x${H14bByte}))

										(( dodump )) && printf "                Supports AI - %s\n" "$( (( H14bByte & 0x80 )) && echo "Yes" || echo "No")"
										
										(( dodump )) &&
											case $(( (H14bByte >> 4) & 7 )) in
												0) echo "                Supports Deep Color - No" ;;
												1) echo "                Supports Deep Color - 10 bpc" ;;
												2) echo "                Supports Deep Color - 12 bpc" ;;
												3) echo "                Supports Deep Color - 10 bpc, 12 bpc" ;;
												4) echo "                Supports Deep Color - 16 bpc" ;;
												5) echo "                Supports Deep Color - 10 bpc, 16 bpc" ;;
												6) echo "                Supports Deep Color - 12 bpc, 16 bpc" ;;
												7) echo "                Supports Deep Color - 10 bpc, 12 bpc, 16 bpc" ;;
											esac
										if (( do8bpc )); then
											local newH14bByte=$(( H14bByte & ~0x70 ))
											replacebytes $((blockoffset+CTAdatablockoffset+6)) "$(printf "%02x" $newH14bByte)"
											(( dodump )) && echo "                    changed: Supports Deep Color - No"
										fi

										(( dodump )) && printf "                Supports Deep Color YCbCr 4:4:4 - %s\n" "$( (( H14bByte & 0x08 )) && echo "Yes" || echo "No")"
										if (( doRGB )); then
											local newH14bByte=$(( (H14bByte & ~0x08) | (0 << 3) )) # 0: No (RGB only), 1: Yes (YCbCr 4:4:4)
											replacebytes $((blockoffset+CTAdatablockoffset+6)) "$(printf "%02x" $newH14bByte)"
											(( dodump )) && echo "                    changed: Support YCbCr 4:4:4 - No"
										fi

										if (( do422 )); then
											local newH14bByte=$(( (H14bByte & ~0x08) | (1 << 3) )) # 0: No (RGB only), 1: Yes (YCbCr 4:4:4)
											replacebytes $((blockoffset+CTAdatablockoffset+6)) "$(printf "%02x" $newH14bByte)"
											(( dodump )) && echo "                    changed: Support YCbCr 4:4:4 - Yes"
										fi

										(( dodump )) && printf "                Supports DVI Dual-Link - %s\n" "$( (( H14bByte & 0x01 )) && echo "Yes" || echo "No")"
									fi
									;;
								c45dd8)
									(( dodump )) && echo " HDMI Forum -> HF-VSDB"
									HFByte=$((0x${CTAdatablock:14:2}))
									HF=$(( (HFByte >> 0) & 7 ))
									(( dodump )) &&
										case $HF in
											0) echo "                4:2:0 10/12/16 bpc - No" ;;
											1) echo "                4:2:0 10 bpc - Yes" ;;
											2) echo "                4:2:0 12 bpc - Yes" ;;
											3) echo "                4:2:0 10/12 bpc - Yes" ;;
											4) echo "                4:2:0 16 bpc - Yes" ;;
											5) echo "                4:2:0 10/16 bpc - Yes" ;;
											6) echo "                4:2:0 12/16 bpc - Yes" ;;
											7) echo "                4:2:0 10/12/16 bpc - Yes" ;;
										esac

									if (( doRGB )); then
										newHFByte=$(( (HFByte & ~0x07) | (0 << 0) ))
										replacebytes $((blockoffset+CTAdatablockoffset+7)) "$(printf "%02x" $newHFByte)"
										(( dodump )) &&  echo "                    changed: 4:2:0 10/12/16 bpc - No"
									fi

									if (( do422 )); then
										newHFByte=$(( (HFByte & ~0x07) | (7 << 0) ))
										replacebytes $((blockoffset+CTAdatablockoffset+7)) "$(printf "%02x" $newHFByte)"
										(( dodump )) &&  echo "                    changed: 4:2:0 10/12/16 bpc - Yes"
									fi
									;;
								*)
									(( dodump )) && echo " Unknown OUI"
									;;
							esac
							;;
						*)
							(( dodump )) && echo
							;;
					esac
					
					if (( willberemoved )); then
						((detailedTimingDescriptorsOffset-=CTAdatablocklength))
						replacebytes $((blockoffset+2)) "$(printf "%02x" "$detailedTimingDescriptorsOffset")"
						local nextctablockoffset=$((CTAdatablockoffset+CTAdatablocklength))
						replacebytes $((blockoffset+CTAdatablockoffset)) "${theedid:(blockoffset+nextctablockoffset)*2:(127-nextctablockoffset)*2}${CTAdatablock//?/0}"
						theblock=${theedid:$blockoffset*2:254}
						(( dodump )) &&  echo "                changed: deleted"
					else
						ctablocks+=("$CTAdatablock")
						((CTAdatablockoffset+=CTAdatablocklength))
						EndOfLastctablock=$((blockoffset + CTAdatablockoffset))
					fi
				done
				(( dodump && (ctablocksAdded > 0) )) && echo "        changed: added $ctablocksAdded"
				
				if ((CTAdatablockoffset < detailedTimingDescriptorsOffset || detailedTimingDescriptorsOffset + 18 > 0x7f )); then
					(( dodump )) && echo "        $((blockoffset + CTAdatablockoffset)))"
				fi
			fi
	
			# Process CTA descriptors
			
			detailed_blocks $((blockoffset+detailedTimingDescriptorsOffset)) $((blockoffset + 127)) "$dodump" "$doreplacedescriptoroffset" "$deletedescriptoroffset" "$replacementdescriptor"

			local ctadescriptorblockoffset=$((detailedTimingDescriptorsOffset))
			local ctadescriptorlength=18
			while (( ctadescriptorblockoffset + 18 <= afterctadescriptorblockoffset )); do
				local ctadescriptor=${theblock:$ctadescriptorblockoffset*2:$ctadescriptorlength * 2}
				case ${ctadescriptor} in
					000000000000000000000000000000000000) ;; # "Empty"
					000000100000000000000000000000000000) ;; # "Dummy block"
					*)
						ctadescriptors+=("$ctadescriptor")
						EndOfLastctadescriptor=$((blockoffset + ctadescriptorblockoffset + ctadescriptorlength))
						;;
				esac
				((ctadescriptorblockoffset+=ctadescriptorlength))
			done

			(( dodump && (ctadescriptorsAdded > 0) )) && echo "        changed: added $ctadescriptorsAdded"

		elif [[ $blocktag = 70 ]]; then
			(( debug )) && echo ": parsing DisplayID extension block" 1>&2

			#	00 edid tag 70
			#
			#	01 		1	DisplayID version
			#	02 		2	DisplayID len 0x79
			#	03 		3	DisplayID product type
			#	04 		4	DisplayID nextcount
			#		
			#	05 00 		DisplayID block #1
			#	06 01 		DisplayID block #1 revision
			#	07 02 		DisplayID block #1 length
			#	
			#	7E 		5	displayID checksum
			#
			#	7F EDID checksum

			DisplayIDversion=${theblock:2:1}.${theblock:3:1}

			# maximum length of DisplayID section in an EDID extension block is 121 = 0x79 bytes.
			# this is the length of all the DisplayID blocks
			DisplayIDlength=$((0x${theblock:4:2}))
			DisplayIDproducttype=$((0x${theblock:6:2}))
			#DisplayIDextcount=$((0x${theblock:8:2}))
			
			DisplayIDblockoffset=5
			if (( doadddisplayidblockoffset == -1 )); then
				doadddisplayidblockoffset=$((blockoffset + DisplayIDblockoffset))
			fi
			
			local newdisplayidblock=""
			local newDisplayIDblocklength=0
			local lastDisplayIDblockoffset=0
			local displayidblocksAdded=0

			local overflow=0
			while (( DisplayIDblockoffset < DisplayIDlength + 5 )); do

				if (( blockoffset + DisplayIDblockoffset == doadddisplayidblockoffset )); then
					(( debug )) && echo ": found DisplayID block $doadddisplayidblockoffset" 1>&2
					# concatenate all the new blocks that will fit
					while (( currentnewdisplayidblock < ${#newdisplayidblocks[@]} )); do
						local DisplayIDblock=${newdisplayidblocks[currentnewdisplayidblock+arrstart]}
						(( debug )) && echo ": testing $DisplayIDblock" 1>&2
						if (( ${#DisplayIDblock}/2 > 0x79 )); then
							echo "Error: DisplayID block is too large: ${DisplayIDblock}" 1>&2
						else
							if (( (${#newdisplayidblock} + ${#DisplayIDblock})/2 > 0x7e - DisplayIDblockoffset )); then
								(( debug )) && echo ": overflow" 1>&2
								overflow=1
								break
							fi
							newdisplayidblock+="${DisplayIDblock}"
							((displayidblocksAdded++))
							(( debug )) && echo ": $displayidblocksAdded: concetenate result: $newdisplayidblock" 1>&2
						fi
						((currentnewdisplayidblock++))
					done
					newdisplayidblocks=("${newdisplayidblocks[@]:$currentnewdisplayidblock}")
					currentnewdisplayidblock=0
					newDisplayIDblocklength=$((${#newdisplayidblock}/2))
					
					if (( displayidblocksAdded == 0 )); then
						# none fit here, try in the next block
						doadddisplayidblockoffset=-1
					fi
				fi

				# stop when the remaining bytes are 0
				local remains=${theblock:$DisplayIDblockoffset * 2:($DisplayIDlength + 5 - $DisplayIDblockoffset)*2}
				if [ -z "${remains//0/}" ]; then
					break
				fi

				local DisplayIDblocklength=$((0x${theblock:$DisplayIDblockoffset * 2 + 4:2} + 3))
				
				# blocks that won't fit are inserted into a list that will be added later
				if (( overflow || (DisplayIDblockoffset + DisplayIDblocklength + newDisplayIDblocklength > 0x7e) )); then
					overflow=1
					local DisplayIDblock=${theblock:$DisplayIDblockoffset*2:$DisplayIDblocklength * 2}
					newdisplayidblocks+=("$DisplayIDblock")
					if ((lastDisplayIDblockoffset == 0)); then
						lastDisplayIDblockoffset=$DisplayIDblockoffset
					fi
				fi
				((DisplayIDblockoffset+=DisplayIDblocklength))
			done
			if ((lastDisplayIDblockoffset == 0)); then
				lastDisplayIDblockoffset=$DisplayIDblockoffset
			fi

			(( dodump )) && printf "%s) DisplayID extension block: version %s, type %d\n" $blockoffset "$DisplayIDversion" $DisplayIDproducttype
			DisplayIDblockoffset=5
			
			while (( DisplayIDblockoffset < DisplayIDlength + 5 )); do
				
				if (( blockoffset + DisplayIDblockoffset == doadddisplayidblockoffset )); then
					replacebytes $((doadddisplayidblockoffset)) "$newdisplayidblock${theblock:$DisplayIDblockoffset*2:($lastDisplayIDblockoffset-$DisplayIDblockoffset)*2}"
					doadddisplayidblockoffset=-1
					
					((lastDisplayIDblockoffset+=newDisplayIDblocklength))
					if (( DisplayIDlength + 5 < lastDisplayIDblockoffset )); then
						DisplayIDlength=$((lastDisplayIDblockoffset - 5))
						replacebytes $((blockoffset+2)) "$(printf "%02x" $DisplayIDlength)"
					fi
					theblock=${theedid:$blockoffset*2:254}
				fi
				
				local DisplayIDblocklength=$((0x${theblock:$DisplayIDblockoffset * 2 + 4:2} + 3))
				(( dodump )) && echo -n "    $((blockoffset + DisplayIDblockoffset)))"
				local DisplayIDblock=${theblock:$DisplayIDblockoffset*2:$DisplayIDblocklength * 2}
				local DisplayIDtagcode=${DisplayIDblock:0:2}

				# stop when the remaining bytes are 0
				local remains=${theblock:$DisplayIDblockoffset * 2:($DisplayIDlength + 5 - $DisplayIDblockoffset)*2}
				if [ -z "${remains//0/}" ]; then
					(( dodump )) && echo
					break
				fi

				if (( dodump )); then
					printf " "
					case $DisplayIDtagcode in
						# DisplayID 1.3
						00) printf "Product identification" ;;
						01) printf "Display parameters" ;;
						02) printf "Color characteristics" ;;
						03) printf "Type 1 detailed timing" ;;
						04) printf "Type 2 detailed timing" ;;
						05) printf "Type 3 short timing" ;;
						06) printf "Type 4 DMT timing" ;;
						07) printf "VESA timings" ;;
						08) printf "CTA timings" ;;
						09) printf "Video timing range" ;;
						0a) printf "Product serial number" ;;
						0b) printf "General purpose ASCII string" ;;
						0c) printf "Display device data" ;;
						0d) printf "Interface power sequencing" ;;
						0e) printf "Transfer characterisitics" ;;
						0f) printf "Display interface" ;;
						10) printf "Stereo display interface" ;;
						12) printf "Tiled display topology" ;;
						# DisplayID 2.0
						20) printf "Product ID data" ;;
						21) printf "Display parameters data" ;;
						22) printf "Type 7 timing - detailed timing data" ;;
						23) printf "Type 8 timing - enumerated timing code data" ;;
						24) printf "Type 9 timing - formula-based timing data" ;;
						25) printf "Dynamic video timing range limits data" ;;
						26) printf "Display interface features data" ;;
						27) printf "Stereo display interface data" ;;
						28) printf "Tiled display topology data" ;;
						29) printf "ContainerID data" ;;
								# 2Ah .. 7Dh RESERVED for Additional VESA-defined Data Blocks
						7e) printf "2.0 Vendor-specific data" ;;
						7f) printf "1.3 Vendor-specific data" ;;
						81) printf "CTA DisplayID data" ;;
								# 82h .. FFh RESERVED
						*)
							if (( 0x$DisplayIDtagcode <= 0x1f )); then
								printf "Reserved for legacy"
							elif (( 0x$DisplayIDtagcode <= 0x7d )); then
								printf "Reserved for VESA"
							elif (( 0x$DisplayIDtagcode <= 7f )); then
								printf "Reserved"
							else
								printf "Reserved for external standards"
							fi
							printf " (%s)" "$DisplayIDtagcode"
							;;
					esac
					echo -n ": $DisplayIDblock"
				fi
				
				local willberemoved=0
				if (( blockoffset + DisplayIDblockoffset == deletedisplayidblockoffset )); then
					willberemoved=1
					deletedisplayidblockoffset=0
				fi
				if (( 0x$DisplayIDtagcode == displayidblocktypetodelete )); then
					willberemoved=1
				fi

				case $DisplayIDtagcode in
					03)
						local timing1offset=3
						(( dodump == 1 && DisplayIDblocklength > 23 )) && echo
						while ((timing1offset < DisplayIDblocklength )); do
							local type1timing=${DisplayIDblock:$timing1offset*2:40}
							if (( dodump )); then
								(( DisplayIDblocklength > 23 )) && echo -n "        $((blockoffset+DisplayIDblockoffset+timing1offset))) $type1timing"
							fi
							local type1timingtext=""
							type1timingtext="$(dumptype1timingdescriptor "$type1timing")"
							
							if (( willberemoved == 0 )); then
								thetimings+=("$type1timingtext")
								thetimingsoffsets+=("$(( blockoffset + DisplayIDblockoffset + timing1offset ))")
								thetimingshex+=("$type1timing")
							fi
							
							(( dodump )) && echo " = $type1timingtext"
							((timing1offset+=20))
						done
						;;
					12)
						HasTile=1
						(( dodump )) && printf " = "
						dumptileddisplaytopologyblock "$DisplayIDblock"
						(( dodump )) && echo
						;;
					
					26) (( dodump )) && printf " = "
						dumpdisplayinterfacefeaturesdata "$DisplayIDblock"
						(( dodump )) && echo
						if (( do8bpc || doRGB )); then
							# RGB: 6 8 10 12 14 16
							# 444: 6 8 10 12 14 16
							# 422:   8 10 12 14 16
							# 420:   8 10 12 14 16
							
							local validdepths=$((0x3f3f1f1f))
							if (( do8bpc )); then
								((validdepths &= 0x03030101))
							fi
							if (( doRGB )); then
								((validdepths &= 0xff000000))
							fi
							
							replacebytes $((blockoffset + DisplayIDblockoffset + 3)) "$( printf "%08x" $(( 0x${DisplayIDblock:6:8} & validdepths )) )"
							theblock=${theedid:$blockoffset*2:254}
							DisplayIDblock=${theblock:$DisplayIDblockoffset*2:$DisplayIDblocklength * 2}
							if (( dodump )); then
								printf "                                 changed: %s = " "$DisplayIDblock"
								dumpdisplayinterfacefeaturesdata "$DisplayIDblock"
								echo
							fi
						fi
						;;
					*)
						(( dodump )) && echo
						;;
				esac

				if (( willberemoved )); then
					(( debug )) && echo ":" replacebytes $((blockoffset + DisplayIDblockoffset)) "${theblock:($DisplayIDblockoffset + $DisplayIDblocklength)*2:($lastDisplayIDblockoffset - $DisplayIDblockoffset - $DisplayIDblocklength)*2}${DisplayIDblock//?/0}" 1>&2
					(( debug )) && echo ":" $DisplayIDblockoffset $DisplayIDblocklength "$lastDisplayIDblockoffset" "${DisplayIDblock//?/0}" 1>&2
					replacebytes $((blockoffset + DisplayIDblockoffset)) "${theblock:($DisplayIDblockoffset + $DisplayIDblocklength)*2:($lastDisplayIDblockoffset - $DisplayIDblockoffset - $DisplayIDblocklength)*2}${DisplayIDblock//?/0}"
					((lastDisplayIDblockoffset-=DisplayIDblocklength))
					theblock=${theedid:$blockoffset*2:254}
					(( dodump )) && echo "        changed: deleted"
				else
					DisplayIDblocks+=("$DisplayIDblock")
					((DisplayIDblockoffset+=DisplayIDblocklength))
					EndOfLastDisplayIDblock=$((blockoffset + DisplayIDblockoffset))
				fi
			done
			(( dodump && (displayidblocksAdded > 0) )) && echo "        changed: added $displayidblocksAdded"
		else
			(( dodump )) && echo "$blockoffset) Extension block: type:$blocktag: $theblock"
		fi
		((blockoffset+=128))

		if (( ((blockoffset*2 == ${#theedid}) || (0x${theedid:$blockoffset*2:2} != 2) ) && ((doaddctablockoffset == -1) && (${#newctablocks[@]} > 0) || (doaddctadescriptoroffset == -1) && (${#newctadescriptors[@]} > 0)) )); then
			addctaextensionblock "${CTAversion:=3}" "$YCbCrSupportbyte" "$blockoffset"
		fi
		
		if (( (blockoffset*2 == ${#theedid}) && (doadddisplayidblockoffset == -1) && (${#newdisplayidblocks[@]} > 0) )); then
			adddisplayidextensionblock "${DisplayIDversion:=1.3}" ${DisplayIDproducttype:=0}
		fi
		
	done
	(( dodump )) && echo "$blockoffset) End"


	# post processing

	local timingndx=0
	local tileTimingsCurrent=""
	for ((timingndx = 0 ; timingndx < ${#thetimings[@]} ; timingndx++)); do
		local thetiming="${thetimings[timingndx+arrstart]}"
		local thewidth=${thetiming%%x*}
		local theheight=${thetiming#*x}
		theheight=${theheight%%@*}
		local thetimingrefresh=${thetiming#*@}
		thetimingrefresh=${thetimingrefresh%%Hz*}
		thetimingrefresh=0000${thetimingrefresh/./}
		thetimingrefresh=${thetimingrefresh: -7}
		
		if (( thewidth > maxresH )); then
			maxresH=$thewidth
			maxresV=$theheight
		fi

		if (( HasTile )); then
			if [[ "$thetiming" =~ ${tileSizeH}x${tileSizeV}@([0-9.]+)Hz.* ]]; then
				tileTimingsCurrent+="$thetimingrefresh $thetiming\n"
			fi
		fi
	done

	if (( HasTile )); then
		if [[ -n $tileTimingsCurrent ]]; then
			tileTimings=$(echo "$tileTimingsCurrent" | sort -r)
			tileRefresh=$(( (10#${tileTimings%% *} + 50)/100)) # round to 1 decimal
			if (( tileRefresh % 10 )); then
				tileRefresh=$((tileRefresh / 10)).${tileRefresh: -1}
			else
				tileRefresh=$((tileRefresh / 10))
			fi
		fi
	fi
}


createdetailedtiming () {
	# currently supports only "Normal Display" with "Digital Separate Sync"
	local param=""
	for param in MHz hactive hfront hpulse hback vactive vfront vpulse vback hsync vsync hmm vmm hborder vborder; do
		eval "local $param=\"$1\""; (( $# )) && shift
	done
	local interlaced=0
	[[ -n ${vactive//[^i]} ]] && interlaced=1
	vactive=${vactive//[^0-9]}
	[[ "$hsync" = '+' ]] && hsync=1 || hsync=0
	[[ "$vsync" = '+' ]] && vsync=1 || vsync=0

	local MHzint=$(( (10#$(printf "0%s.000" $MHz | sed -E "s/^([0-9]*)\.([0-9])\.*([0-9])\.*([0-9]).*/\1\2\3\4/g") + 5) / 10))
	local hblank=$((hfront + hpulse + hback))
	local vblank=$((vfront + vpulse + vback))

	printf "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" \
		$((MHzint & 255)) $((MHzint >> 8)) \
		$((hactive & 255)) \
		$((hblank & 255)) \
		$(((hactive >> 8 << 4) + (hblank >> 8))) \
		$((vactive & 255)) \
		$((vblank & 255)) \
		$(((vactive >> 8 << 4) + (vblank >> 8))) \
		$((hfront & 255)) \
		$((hpulse & 255)) \
		$((((vfront & 15) << 4) + (vpulse & 15))) \
		$(((hfront >> 8 << 6) + (hpulse >> 8 << 4) + (vfront >> 4 << 2) + (vpulse >> 4))) \
		$((${hmm:=0} & 255)) \
		$((${vmm:=0} & 255)) \
		$(((${hmm:=0} >> 8 << 4) + (${vmm:=0} >> 8))) \
		${hborder:=0} \
		${vborder:=0} \
		$(((interlaced << 7) + 0x18 + (vsync << 2) + (hsync << 1)))
}


createtype1timingdescriptor () {
	# currently supports only "Normal Display" with "Digital Separate Sync"
	# no 3D, no interlaced
	local param=""
	for param in MHz hactive hfront hpulse hback vactive vfront vpulse vback hsync vsync preferred; do
		eval "local $param=\"$1\""; (( $# )) && shift
	done
	local interlaced=0
	[[ -n ${vactive//[^i]} ]] && interlaced=1
	vactive=${vactive//[^0-9]}
	[[ "$hsync" = '+' ]] && hsync=1 || hsync=0
	[[ "$vsync" = '+' ]] && vsync=1 || vsync=0

	local MHzint=$(((10#$(printf "0%s.000" $MHz | sed -E "s/^([0-9]*)\.([0-9])\.*([0-9])\.*([0-9]).*/\1\2\3\4/g") + 5) / 10))

	local hblank=$((hfront + hpulse + hback))
	local vblank=$((vfront + vpulse + vback))

	local aspect=8
	case $(((hactive * 10000 / vactive + 5)/10)) in
		1000) aspect=0 ;;
		1250) aspect=1 ;;
		1333) aspect=2 ;;
		1667) aspect=3 ;;
		1778) aspect=4 ;;
		1600) aspect=5 ;;
		2370) aspect=6 ;;
		1896) aspect=7 ;;
	esac
	
	((MHzint-=1))

	((hactive-=1))
	((hblank-=1))
	((hfront-=1))
	((hpulse-=1))

	((vactive-=1))
	((vblank-=1))
	((vfront-=1))
	((vpulse-=1))

	printf "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" \
		$((MHzint & 255)) $(((MHzint >> 8) & 255)) $((MHzint >> 16)) \
		$(((${preferred:=0} << 7) + (interlaced << 4) + aspect)) \
		$((hactive & 255)) $((hactive >> 8)) \
		$((hblank & 255)) $((hblank >> 8)) \
		$((hfront & 255)) $((((hfront >> 8) & 127) + (hsync << 7))) \
		$((hpulse & 255)) $((hpulse >> 8)) \
		$((vactive & 255)) $((vactive >> 8)) \
		$((vblank & 255)) $((vblank >> 8)) \
		$((vfront & 255)) $((((vfront >> 8) & 127) + (vsync << 7))) \
		$((vpulse & 255)) $((vpulse >> 8))
}


createtype1timingblock () {
	local type1timingblock=""
	while (( $# )); do
		type1timingblock+=$1
		shift
	done
	printf "0300%02x%s" $((${#type1timingblock}/2)) "$type1timingblock"
}



addchromasubsampling () {
	processedid do422 dodeletectablocktype 70f # = YCbCr 4:2:0 capability map
	repairchecksums
}


removechromasubsampling () {
	processedid doRGB dodeletectablocktype 70f # = YCbCr 4:2:0 capability map
	repairchecksums
}


set8bpcmax () {
	processedid do8bpc dodeletectablocktype 706 707 # = HDR static metadata, HDR dynamic metadata
	repairchecksums
}

deletectablock () {
	processedid dodeletectablock "$1"
	repairchecksums
}


deletectablocktype () {
	processedid dodeletectablocktype "$1"
	repairchecksums
}


addctablock () {
	processedid doaddctablock "$@"
	repairchecksums
}


deletedescriptor () {
	processedid dodeletedescriptor "$1"
	repairchecksums
}


addctadescriptor () {
	processedid doaddctadescriptor "$@"
	repairchecksums
}


replacedescriptor () {
	processedid doreplacedescriptor "$1" "$2"
	repairchecksums
}


cleardate () {
	processedid docleardate
	repairchecksums
}


clearserialnumber () {
	processedid doclearserialnumber
	repairchecksums
}


setpreferredisnative () {
	processedid dosetpreferredisnative "$1"
	repairchecksums
}


clearchromaticity () {
	processedid doclearchromaticity
	repairchecksums
}

clearestablishedtimings () {
	processedid doclearestablishedtimings
	repairchecksums
}


clearmanufacturerstimings () {
	processedid doclearmanufacturerstimings
	repairchecksums
}


clearstandardtimings () {
	processedid doclearstandardtimings
	repairchecksums
}


deletedisplayidblock () {
	processedid dodeletedisplayidblock "$1"
	repairchecksums
}


deletedisplayidblocktype () {
	processedid dodeletedisplayidblockblocktype "$1"
	repairchecksums
}


adddisplayidblock () {
	processedid doadddisplayidblock "$@"
	repairchecksums
}


dumpedid () {
	processedid dodump
}


dumpedidall () {
	local dostdout=0
	local thefolderpath="."
	while (( $# )); do
		case "$1" in
			"-s") dostdout=1 ;;
			*)	thefolderpath="$1" ;;
		esac
		shift
	done

	local saveedid="$theedid"
	local i=""
	for ((i = 1 ; i <= ${#edids[@]} ; i++)); do
		useedidnum "$i"
		if ((dostdout)); then
			echo "=========================================================================================="
			echo "$i)"
			echo "${paths[i+arrstart-1]}"
			echo "=================="
			dumpedid
		else
			dumpedid > "${thefolderpath:=.}/${thefilenamebase}_dumpedid.txt"
		fi
	done
	useedidstring "$saveedid"
}


createdummydescriptor () {
	echo -n "000000100000000000000000000000000000"
}


createemptydescriptor () {
	echo -n "000000000000000000000000000000000000"
}


#=========================================================================================
# Use EDID

clearedidinfo () {
	tileTimings=""
	tileSizeH=""
	tileSizeV=""
	tileRefresh=""
	maxresH=0
	maxresV=0
}

useedidstring () {
	clearedidinfo
	(( debug )) && echo ": useedidstring $1" 1>&2
	theedid="$1"
	processedid
}


useedidnum () {
	clearedidinfo
	theedid=${edids[arrstart - 1 + $1]}
	processedid
	thefilenamebase="${thefilenamebase}_$i"
}


#=========================================================================================
# Get EDID


clearedids () {
	edids=()
	paths=()
}
clearedids


applypatches () {
	thefilename="$1"
	sourcename="$2"
	
	if [[ -f "${thefilename}" ]]; then
		if /usr/libexec/PlistBuddy -c 'Print :edid-patches' "${thefilename}" > /dev/null 2>&1; then
			local index=0
			while [ -n "$(/usr/libexec/PlistBuddy -c "Print :edid-patches:$index:offset" "${thefilename}" 2> /dev/null)" ]; do
			        local theoffset=""
			        local thedata=""
				theoffset=$(/usr/libexec/PlistBuddy -c "Print :edid-patches:$index:offset" "${thefilename}")
				thedata=$(/usr/libexec/PlistBuddy -c "Print :edid-patches:$index:data" "${thefilename}" | xxd -p -c 99999)
				thedata=${thedata%0a} # remove extra linefeed that was added by PlistBuddy
				theedid=${theedid:0:$theoffset*2}${thedata}${theedid:$theoffset*2 + ${#thedata}}
				((index+=1))
			done
			if (( ${#theedid} % 256 == 0 )); then
				if [[ -n $sourcename ]]; then
					addedid "${thefilename}:edid-patches of ($sourcename)" "$theedid"
				else
					addedid "${thefilename}:edid-patches" "$theedid"
				fi
			else
				theedid=""
			fi
		fi
	fi
}


addedid () {
	local saveedid="$theedid"
	local thepath="$1"
	useedidstring "$2"

	local isnew=1
	local i=""
	for ((i = 0 ; i < ${#edids[@]} ; i++)); do
		if [[ $theedid = "${edids[i+arrstart]}" ]]; then
			if [[ ! "$(printf "_\n%s\n_" "${paths[i+arrstart]}")" =~ $(printf ".*\n%s\n.*" "${thepath}") ]]; then
				paths[i+arrstart]="$(printf "%s\n%s" "${paths[i+arrstart]}" "$thepath")"
			fi
			isnew=0
			break
		fi
	done
	
	if (( isnew )); then
		(( debug )) && echo ": isnew" 1>&2
		edids+=("$theedid")
		paths+=("$thepath")
		local newndx=${#edids[@]}
		
		local thefilename=""
		local thedir=""
		for thedir in "/System" ""; do
			local fulldir="$thedir/Library/Displays/Contents/Resources/Overrides"
			for thefilename in "$fulldir/$themanufacturefile" "$fulldir/$theproductfile"; do
				(( debug )) && echo ": checking $thefilename" 1>&2
				if [[ -f "${thefilename}" ]]; then
					loadoverridefile "${thefilename}"
					[[ -n $lastoverrideedid ]] && theedid=$lastoverrideedid
					applypatches "${thefilename}" "$newndx"
				fi
			done
			for thefilename in "$fulldir/${themanufacturefile}.mtdd" "$fulldir/${theproductfile}.mtdd"; do
				(( debug )) && echo ": checking $thefilename" 1>&2
				if [[ -f "${thefilename}" ]]; then
					loadmtddfile "${thefilename}"
				fi
			done
		done
	fi
	useedidstring "$saveedid"
}


loadoverridefile () {
	while (( $# )); do
		local thefilename=""
		thefilename="$1"
		shift
		# lastoverrideedid is not local
		lastoverrideedid=$(/usr/libexec/PlistBuddy -c 'Print :IODisplayEDID' "${thefilename}" 2> /dev/null | xxd -p -c 99999)
		lastoverrideedid=${lastoverrideedid%0a} # remove extra linefeed that was added by PlistBuddy
		[[ -n $lastoverrideedid ]] && addedid "${thefilename}:IODisplayEDID" "$lastoverrideedid"

		local theedid=""
		theedid=$(/usr/libexec/PlistBuddy -c 'Print :"SwitchResX backuped settings":IODisplayEDID' "${thefilename}" 2> /dev/null | xxd -p -c 99999)
		theedid=${theedid%0a} # remove extra linefeed that was added by PlistBuddy
		[[ -n $theedid ]] && addedid "${thefilename}:SwitchResX backuped settings:IODisplayEDID" "$theedid"
	done
}


loadmtddfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		local theedid=""
		theedid=$(/usr/libexec/PlistBuddy -c 'Print :display:overlay' "${thefilename}" 2> /dev/null | xxd -p -c 99999)
		theedid=${theedid%0a} # remove extra linefeed that was added by PlistBuddy
		[[ -n $theedid ]] && addedid "${thefilename}:overlay" "$theedid"
	done
}


loadswitchresxfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		local theedid=""
		theedid=$(sed -n -E -e $'/^ *<([0-9A-F \t]+)[ \t]*>/s//\\1/p' "${thefilename}" | xxd -r -p | xxd -p -c 99999)
		addedid "${thefilename}:switchresx" "$theedid"
	done
}


loadmamhexfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		local theedid=""
		theedid=$(sed -n -E -e "/^:[0-9A-F]{8}([0-9A-F]{64})[0-9A-F]{2}.?$/s//\1/p" "${thefilename}" | xxd -p -r | xxd -p -c 99999)
		addedid "${thefilename}:Monitor Asset Manager.hex" "$theedid"
	done
}


loadmaminffile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		local theedid=""
		theedid=$(sed -n -E -e '/^HKR,EDID_OVERRIDE,".+",0x01((,0x[0-9A-F]{2})*).?$/s//\1/;s/,0x//gp' "${thefilename}" | xxd -p -r | xxd -p -c 99999)
		addedid "${thefilename}:Monitor Asset Manager.hex" "$theedid"
	done
}


loadmamdatfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		local theedid=""
		theedid=$(sed -n -E -e '/^[0-9A-F]{2,4} \|(( [0-9A-F]{2})*).?$/s//\1/p' "${thefilename}" | xxd -r -p | xxd -p -c 99999)
		addedid "${thefilename}:Monitor Asset Manager.dat" "$theedid"
	done
}


numstrings=0
loadstring () {
	local theedid="$1"
	local sourcename="$2"
	theedid=$(echo ${theedid//0x/} | tr -d ' \n\r\t,$')
	if [[ -z $sourcename ]]; then
		((numstrings++))
		sourcename="string:$numstrings"
	fi
	addedid "$sourcename" "$(tr 'A-F' 'a-f' <<< "$theedid")"
}


loadcurrentedid () {
	loadstring "$theedid" "$1"
}


loadbinfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		addedid "$thefilename" "$(xxd -p -c 99999 < "$thefilename")"
	done
}


loadhexfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		addedid "$thefilename" "$(
			if [[ -z $(tr -d 'a-fA-F0-9 \n\t' < "$thefilename") ]]; then
				xxd -p -r < "$thefilename"
			else
				xxd -r < "$thefilename"
			fi | xxd -p -c 99999
		)"
	done
}


loadoneediditem () {
	local ediditem="$1"
	local thepath="${ediditem% = <*}"
	local theedid="${ediditem##* = <}"
	local theedid="${theedid%>}"
	(( debug )) && echo ":" addedid "${thepath}" "${theedid}" 1>&2
	addedid "${thepath}" "${theedid}"
}


loadagdcfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		IFS=$'\n'
		local ediditem=""
		for ediditem in $(
			perl -e '
				$thepath=""; while (<>) {
					if ( m|^(?:\[\d+\] )?IOService:(/.*)| ) { $thepath = $1 }
					if ( /^[#|]* ?EDID Dump (Port \d+) - Start( ##)?/ ) { $theport = $1; $edid = "" }
					if ( m|^(  )?/\*? ...: \*?/  ?(.*)| ) { $edid .= $2 }
					if ( /^(## )?EDID Dump (Port \d+) - End( ##)?/ and length $edid > 0 ) { $edid =~ s/0x(..)(, *)?/$1/g; print "'"${thefilename}"':" . $thepath . "/" . $theport . " = <" . $edid . ">\n" }
				}
			' < "${thefilename}"
		); do
			(( debug )) && echo ":" loadoneediditem "${ediditem}" 1>&2
			loadoneediditem "${ediditem}"
		done
	done
}


loadmamfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		IFS=$'\n'
		local ediditem=""
		for ediditem in $(
			perl -e '
				$thepath=""; while (<>) {
					if ( m|^(Monitor( #.*\S)?)\s*$| ) { $thepath = $1 }
					if ( /^Raw data.?$/ ) { $edid = "" }
					if ( m| *(([0-9A-F]{2},){31}[0-9A-F]{2},).?$| ) { $edid .= $1 }
					if ( m| *(([0-9A-F]{2},){31}[0-9A-F]{2})[^,]*$| ) { $edid .= $1 . ","; $edid =~ s/(..),/$1/g; print "'"${thefilename}"':" . $thepath . " = <" . lc $edid . ">\n" }
				}
			' < "${thefilename}"
		); do
			(( debug )) && echo ":" loadoneediditem "${ediditem}" 1>&2
			loadoneediditem "${ediditem}"
		done
	done
}


loadagdc () {
	local thefilename="$1"
	if [[ -z $thefilename ]]; then
		thefilename=$(mktemp /tmp/local_AGDCDiagnose.XXXXXX) || exit 1
	fi
	/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > "$thefilename" 2>&1
	loadagdcfile "$thefilename"
}


loadioregfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		IFS=$'\n'
		local ediditem=""
		for ediditem in $(
			perl -e '
				$thepath=""; while (<>) {
					if ( /^([ |]*)\+\-o (.+)  </ ) { $indent = (length $1) / 2; $name = $2; $thepath =~ s|^((/[^/]*){$indent}).*|$1/$name| }
					if ( /^[ |]*"([^"]+)" = <(00ffffffffffff00[0-9a-f]*)>/i ) { print "'"${thefilename}"'" . ":" . $thepath . "/" . $1 . " = <" . $2 . ">\n" }
				}
			' < "${thefilename}"
		); do
			loadoneediditem "${ediditem}"
		done
	done
}

loadallrezfile () {
	while (( $# )); do
		local thefilename="$1"
		shift
		IFS=$'\n'
		local ediditem=""
		for ediditem in $(
			perl -e '
				$agdcpath="";
				$thepath=""; while (<>) {
					if ( /^( *)(\w.*?) += \{$/ ) { $indent = (length $1) / 4; $name = $2 =~ s|/|•|gr; $thepath =~ s|^((/[^/]*){$indent}).*|$1/$name| }
					elsif ( /^( *)\}.*$/ ) { $indent = (length $1) / 4; $thepath =~ s|^((/[^/]*){$indent}).*|$1| }
					if ( /^ *(\w.*?) += (00ffffffffffff00[0-9a-f]*)/i ) { $var = $1; $edid = $2; print "'"${thefilename}"'" . ":" . ($thepath =~ s|•|/|gr) . "/" . $var . " = <" . $edid . ">\n" }
					if ( m|^(?:\[\d+\] )?IOService:(/.*)| ) { $agdcpath = $1 }
					if ( /^[#|]* ?EDID Dump (Port \d+) - Start( ##)?/ ) { $theport = $1; $edid = "" }
					if ( m|^(  )?/\*? ...: \*?/  ?(.*)| ) { $edid .= $2 }
					if ( /^(## )?EDID Dump (Port \d+) - End( ##)?/ and length $edid > 0 ) { $edid =~ s/0x(..)(, *)?/$1/g; print "'"${thefilename}"':" . $agdcpath . "/" . $theport . " = <" . $edid . ">\n" }
				}
			' < "${thefilename}"
		); do
			loadoneediditem "${ediditem}"
		done
	done
}


loadioreg () {
        local tmpfilename=""
	tmpfilename=$(mktemp /tmp/local_ioreg.XXXXXX) || exit 1
	ioreg -lw0 > "$tmpfilename"
	loadioregfile "$tmpfilename"
}


listedids () {
	local saveedid="$theedid"
	local i=""
	for ((i = 1 ; i <= ${#edids[@]} ; i++)); do
		useedidnum "$i"
	
		echo "$i)"
		echo "vendor:$thevendorid ($thevendorcode) product:$theproductid ID:${thevendorcode}$(printf "%04X" $theproductid)/$(printf "$theedid" | md5 | sed -E 's/(.{12}).*/\1/' | tr 'abcdef' 'ABCDEF')"
		echo "override product name:$theproductfile"
		echo "override date name:$themanufacturefile"
		echo "strings:$(echo -n "$theedid" | xxd -p -r | strings - | tr -s '\n\t ' ' ' | sed '/ *$/s///' )"
		echo "theedid=$theedid"
		echo "sources:"
		echo "${paths[i+arrstart-1]}"
		echo
	done
	useedidstring "$saveedid"
}


#=========================================================================================
# Files from EDID


edidbin () {
	echo -n "$theedid" | xxd -p -r
}


edidbinall () {
	local saveedid="$theedid"
	local thefolderpath="$1"
	local i=""
	for ((i = 1 ; i <= ${#edids[@]} ; i++)); do
		useedidnum "$i"
		edidbin > "${thefolderpath:=.}/${thefilenamebase}.bin"
	done
	useedidstring "$saveedid"
}


decode () {
        local tmpfilename=""
	tmpfilename=$(mktemp /tmp/edidbin.XXXXXX) || exit 1
	edidbin > "$tmpfilename"
	"$edid_decode" -cC --skip-sha "$tmpfilename" 2>&1
}


decodeall () {
	local dostdout=0
	local thefolderpath="."
	while (( $# )); do
		case "$1" in
			"-s") dostdout=1 ;;
			*)	thefolderpath="$1" ;;
		esac
		shift
	done

	local saveedid="$theedid"
	local i=""
	for ((i = 1 ; i <= ${#edids[@]} ; i++)); do
		useedidnum "$i"
		if ((dostdout)); then
			echo "=========================================================================================="
			echo "$i)"
			echo "${paths[i+arrstart-1]}"
			echo "=================="
			decode
		else
			decode > "${thefolderpath:=.}/${thefilenamebase}_edid-decode.txt"
		fi
	done
	useedidstring "$saveedid"
}


agdcdevicedump () {
	# Indent the Device Dump section of a AGDCDiagnose file.
	# Note that some DICT sizes seem to be greater than the number of lines included in the dump.
	local thefilename="$1"
	perl -e '
		sub dict {
			my $indent = $_[0];
			my $lines = $_[1];
			while ($lines-- != 0) {
				my $theline = "";
				do {
					$theline = <>;
				} until ($theline !~ /^$/);
				die if ($theline =~ /\-\-END Device Dump\-\-/);
				print $indent.$theline;
				dict($indent."\t", $1) if ($theline =~ /^.*[\t ]DICT[\t ]+(\d+)\n$/);
			}
		}
		while (<>) { if ( /\-\-BEGIN Device Dump\-\-/ ) { print "----------------\n"; eval { dict("", -1); } } }
	' < "$thefilename"
}


updateoverride () {
	local thefilename="$1"
	plutil -replace IODisplayEDID -data "$(echo -n "$theedid" | xxd -p -r | base64)" "${thefilename}"
	plutil -replace DisplayProductID -integer $((0x${theedid:22:2}${theedid:20:2})) "${thefilename}"
	plutil -replace DisplayVendorID -integer $((0x${theedid:16:4})) "${thefilename}"
}


makeoverride () {
	local noedid=0
	if [[ $1 == '-noedid' ]]; then
		noedid=1
		shift
	fi

	local thefilename="${theproductfile}"
	if [[ $1 == '-m' ]]; then
		thefilename="$themanufacturefile"
		shift
	fi
	if [[ -z $1 ]]; then
		[[ -d "${thevendordir}" ]] || mkdir "${thevendordir}"
	else
		thefilename="$1"
	fi

	[[ -f "${thefilename}" ]] && rm "${thefilename}"
	/usr/libexec/PlistBuddy \
		-c "Add :DisplayProductID integer ${theproductid}" \
		-c "Add :DisplayVendorID integer ${thevendorid}" \
		-c 'Add :IODisplayEDID data ""' \
		-c 'Add :DisplayPixelDimensions data ""' \
		"${thefilename}" > /dev/null
	plutil -replace 'IODisplayEDID' -data "$(echo -n "$theedid" | xxd -p -r | base64)" "${thefilename}"
	# the hex is big endian
	plutil -replace 'DisplayPixelDimensions' -data "$(printf "%08x%08x" $maxresH $maxresV | xxd -p -r | base64)" "${thefilename}"
	if (( noedid )); then
		plutil -remove 'IODisplayEDID' "${thefilename}"
	fi

#	// IOGraphicsLibInternal.h  flags for IOGFlags in override file
#	enum {
#		// disable any use of scaled modes,
#		kOvrFlagDisableScaling	= 0x00000001,
#		// remove driver modes,
#		kOvrFlagDisableNonScaled	= 0x00000002,
#		// disable scaled modes made up by the system (just use the override list)
#		kOvrFlagDisableGenerated	= 0x00000004
#	};
}


installoverride () {
	local thedir="/System"
	local dstfile="$theproductfile"
	local thefilename=""
	
	while (( $# )); do
		if [[ $1 == '-l' ]]; then
			thedir=""
		elif [[ $1 == '-m' ]]; then
			dstfile="$themanufacturefile"
		else
			thefilename="$1"
		fi
		shift
	done
	
	[[ -z $thefilename ]] && thefilename="${dstfile}"

	echo "# source file: ${thefilename}"

	mount | grep ' on / ' | grep -q 'read-only' && sudo mount -uw /
	local fulldir="$thedir/Library/Displays/Contents/Resources/Overrides"
	[[ -d "${fulldir}/${thevendordir}" ]] || sudo mkdir -p "${fulldir}/${thevendordir}"
	sudo cp "${thefilename}" "${fulldir}/${dstfile}"
	echo "# Installed file: ${fulldir}/${dstfile}"
	if [[ "$(basename "${dstfile}")" =~ DisplayProductID-.* ]]; then
		[[ -f ${fulldir}/$themanufacturefile ]] && echo "# Warning: alternative override exists at ${fulldir}/$themanufacturefile"
	else
		[[ -f ${fulldir}/$theproductfile ]] && echo "# Warning: alternative override exists at ${fulldir}/$theproductfile"
	fi
}


makemtdd () {
	local donew=0
	local thefilename=""
	while (( $# )); do
		case "$1" in
			"-n") donew=1 ;;
			*)	thefilename="$1" ;;
		esac
		shift
	done
	
	if [[ -z ${thefilename} ]]; then
		[[ -d "${thevendordir}" ]] || mkdir "${thevendordir}"
		thefilename="${theproductfile}.mtdd"
	fi

	[[ -f "${thefilename}" ]] && rm "${thefilename}"

	/usr/libexec/PlistBuddy \
		-c 'Add display dict' \
		-c 'Add :display:linkmode string multi-cable' \
		-c 'Add :display:overlay data ""' \
		-c "Add :display:streamcount integer $((tileCountH * tileCountV))" \
		-c "Add :display:tileinfo string ($tileCountH,$tileCountV)" \
		-c "Add :productid string $(printf "0x%04x" $theproductid)" \
		-c "Add :serial integer 1" \
		-c "Add :vendorid string $(printf "0x%04x" $thevendorid)" \
		-c "Add :version string 1.3" \
		"${thefilename}" > /dev/null

	if (( donew )); then
		plutil -insert 'display.backendtiming' -xml "<array>$(echo "$tileTimings" | perl -pe's/^[0-9]+ ([0-9]+)x([0-9]+)@([0-9.]+)Hz [0-9.]+kHz ([0-9]+)\.([0-9]+)MHz  h\(([0-9]+) ([0-9]+) ([0-9]+) ([-+])\)  v\(([0-9]+) ([0-9]+) ([0-9]+) ([-+])\).*/"<string>$1,$6,$7,".($1+$6+$7+$8)."x$2,$10,$11,".($2+$10+$11+$12)."\@$4${5}0000,$9$13<\/string>"/e')<string>*</string></array>" "${thefilename}"
		plutil -insert 'display.frontendtiming' -xml "<array>$(echo "$tileTimings" | perl -pe's/^[0-9]+ ([0-9]+)x([0-9]+)@([0-9.]+)Hz [0-9.]+kHz ([0-9]+)\.([0-9]+)MHz  h\(([0-9]+) ([0-9]+) ([0-9]+) ([-+])\)  v\(([0-9]+) ([0-9]+) ([0-9]+) ([-+])\).*/"<string>".($1*2).",".($6*2).",".($7*2).",".($1+$6+$7+$8)."x$2,$10,$11,".($2+$10+$11+$12)."\@".("$4${5}0000" * 2).",$9$13<\/string>"/e')</array>" "${thefilename}"
	else
		plutil -insert 'display.backendtiming' -string "${tileSizeH}x${tileSizeV}@${tileRefresh}" "${thefilename}"
		plutil -insert 'display.frontendtiming' -string "$((tileSizeH * 2))x${tileSizeV}@${tileRefresh}" "${thefilename}"
	fi
	plutil -replace 'display.overlay' -data "$(echo -n "$theedid" | xxd -p -r | base64)" "${thefilename}"
	if (( HasAudio )); then
		plutil -insert 'display.audio' -string '(1,1)' "${thefilename}"
	fi
	
	echo "# Created mtdd file: ${thefilename}"
}


makepatch () {
	local thefilename="$1"
	if [[ -z ${thefilename} ]]; then
		[[ -d "${thevendordir}" ]] || mkdir "${thevendordir}"
		thefilename="${theproductfile}"
	fi

	[[ -f "${thefilename}" ]] && rm "${thefilename}"

	/usr/libexec/PlistBuddy \
		-c "Add :DisplayProductID integer ${theproductid}" \
		-c "Add :DisplayVendorID integer ${thevendorid}" \
		-c 'Add edid-patches array' \
		"${thefilename}" > /dev/null

		local i=""
		for ((i = 0 ; i < ${#patches[@]} ; i++)); do
			local thepatch="${patches[i+arrstart]}"
			local offset=$((${thepatch%:*}))
			local data=${thepatch#*:}
			plutil -insert "edid-patches.$i" -xml "<dict>
	<key>offset</key>
	<integer>$offset</integer>
			<key>data</key>
			<data>$(echo -n "$data" | xxd -p -r | base64)</data>
</dict>" "${thefilename}"
		done
	
		echo "# Created patch file: ${thefilename}"
}


makemtddall () {
	local saveedid="$theedid"
	local thefolderpath="$1"
	local i=""
	for ((i = 1 ; i <= ${#edids[@]} ; i++)); do
		useedidnum "$i"
		[[ -d "${thefolderpath:=.}/${thevendordir}" ]] || mkdir "${thefolderpath}/${thevendordir}"
		makemtdd "${thefolderpath}/$theproductfile".mtdd
	done
	useedidstring "$saveedid"
}


translateoui () {
	local oui=$1
	if [[ $oui =~ ([0-9]+)-([0-9]+)-([0-9]+) ]]; then
		oui="$(eval "$(echo -n "$oui" | sed -E '/([0-9]+)-([0-9]+)-([0-9]+)/s//printf "%02X%02X%02X" \1 \2 \3/')")"
	else
		oui=${oui//-/}
		oui=${oui//0x/}
		oui=$(printf "%06X" $((0x$oui)))
	fi
	
	local thetype=""
	for thetype in oui cid; do
		[[ -f ~/${thetype}.txt ]] || curl -s "http://standards-oui.ieee.org/${thetype}/${thetype}.txt" > ~/${thetype}.txt
		local thetranslate=""
		thetranslate="$(sed -nE '/^'"$oui"'[ ]+\(base 16\)*(.*)/s//\1/p' ~/${thetype}.txt | tr -d '\t\r')"
		[[ -n $thetranslate ]] && echo "$thetype: 0x$oui = $thetranslate"
	done
}


translatevendor () {
	local thevendorid=$1
	local vendorascii=""
	local pnppattern="^[A-Za-z]{3}$"
	if [[ $thevendorid =~ $pnppattern ]]; then
		thevendorid=$(printf "%s" "$thevendorid" | xxd -p)
		thevendorid=$(( (0x${thevendorid:0:2} & 31) << 10 + (0x${thevendorid:2:2} & 31) << 5 + (0x${thevendorid:4:2} & 31) ))
	else
		thevendorid=$((thevendorid))
	fi
	vendorascii=$(printf "%06x" $((((thevendorid&0x7c00)<<6)+((thevendorid&0x3e0)<<3)+(thevendorid&0x1f)+0x404040)) | xxd -p -r)
	if [[ ! -f ~/pnp_id_list.txt ]]; then
		curl -s "https://uefi.org/uefi-pnp-export" | \
		tidy -wrap 0 -raw -utf8 -q | \
		perl -0777 -nE '
			s!(?:&nbsp;)*(</td>)!\1!g;
			s!&amp;!&!g;
			while (
				m!
					^<tr\ class=\"(?:odd|even)">\n
					<td>(.*)</td>\n
					<td>(...)</td>\n
					<td>(../../....)</td>\n
					</tr>
				!xmg
			) { 
				print $3 . " " . $2 . " " . $1 . "\n"
			}
		' | \
		sort -f -k 3 -k 2 -k 1 > ~/pnp_id_list.txt
	fi
	
	printf "0x%04x = %s = %s\n" $thevendorid "$vendorascii" "$(sed -nE '/[0-9/]+ '"$vendorascii"' (.*)/s//\1/p' ~/pnp_id_list.txt)"
	
	# $(sed -nE '/^'$oui'[ ]+\(base 16\)*(.*)/s//\1/p' ~/oui.txt | tr -d '\t\r')
}


#=========================================================================================

edidhelp () {
	cat << edidhelp_done
Commands:
	Get EDID
		loadagdc [dstfilepath]
		loadioreg
		loadstring hexstring [sourcename]
		loadcurrentedid [sourcename]
		loadbinfile filepath...
		loadhexfile filepath... # reverses xxd
		loadagdcfile filepath...
		loadioregfile filepath...
		loadoverridefile filepath...
		loadmtddfile filepath...
		loadswitchresxfile filepath...
		loadmamfile filepath... # Monitor Asset Manager.txt
		loadmamhexfile filepath... # Monitor Asset Manager.hex
		loadmaminffile filepath... # Monitor Asset Manager.inf
		loadmamdatfile filepath... # Monitor Asset Manager.dat

		listedids
		clearedids

	Use EDID
		useedidnum numberfromlist
		useedidstring lowercasehexstring

	Modify EDID
		repairchecksums
		
		replacebytes bytepos lowercasehexstring [numbytestoreplace]

		deleteextensionblock blocknumber
		deleteextensionblocktype blocktype(decimal or 0xhex)
		adddisplayidextensionblock version producttype
		addctaextensionblock version [YCbCrSupportbyte offset]

		addchromasubsampling
		removechromasubsampling
		set8bpcmax
		cleardate
		clearserialnumber
		setpreferredisnative preferredvalue(0/1)
		clearchromaticity
		clearestablishedtimings
		clearmanufacturerstimings
		clearstandardtimings

		deletectablock offset
		deletectablocktype ctablocktype(1, 2, ..., 6, 700, 701, ..., 70f, 710, ..., hex for extended)
 		addctablock offset newctablock... # -1 = insert before first CTA block; 0 = insert after last CTA block

		deletedescriptor offset
 		addctadescriptor offset newctadescriptor... # -1 = insert before first CTA block; 0 = insert after last CTA block

		createdetailedtiming MHz hactive hfront hpulse hback vactive[i=interlaced] vfront vpulse vback hsync(+/-) vsync(+/-) [hmm] [vmm] [hborder] [vborder]
		createdummydescriptor
		createemptydescriptor
		replacedescriptor offset replacementdescriptor

		createtype1timingdescriptor MHz hactive hfront hpulse hback vactive[i=interlaced] vfront vpulse vback hsync(+/-) vsync(+/-) [preferred(1/0)]
		createtype1timingblock descriptors...
		dumptype1timingdescriptor 20_byte_descriptor
		deletedisplayidblock offset
		deletedisplayidblocktype displayidblocktype(decimal or 0xhex)
 		adddisplayidblock offset newdisplayidblock... # -1 = insert before first DisplayID block; 0 = insert after last DisplayID block
 		
 		applypatches filepath [sourcename]
		
	Files from EDID
		makemtdd [-n] [filepath]
			The edid needs to be manually edited.
				clearserialnumber
				cleardate
				#clearchromaticity
				#clearestablishedtimings
				#clearstandardtimings
				#clearmanufacturerstimings
				#removechromasubsampling
				deletedisplayidblocktype 3 # remove type 1 DisplayID timings
				deletedisplayidblocktype 0x12 # remove tile topology
				# Add the deleted type 1 DisplayID timings, except replace the tile timing (backend timing) with a full size timing (frontend timing).
				# Frontend timing in this example doubles the MHz and horizontal numbers of the backend timing.
				adddisplayidblock 0 \$(createtype1timingblock 9aa00104ff0ea0002f8021006f083e0003000500 \$(createtype1timingdescriptor 1264.02 3840 96 64 20 2160 2 4 20 + - 1 ))
		makepatch [filepath]
			Creates an override file with edid-patches array from shell array variable called patches. e.g. patches=("94:0818900a" "304:7f00080000000000000000")

		makemtddall [folderpath]
		makeoverride [-noedid] [-m | dstfilepath]
		updateoverride filepath
		installoverride [-l] [-m] [srcfilepath]
		decode
		decodeall [-s | folderpath]
		edidbin
		edidbinall [folderpath]
		dumpedid
		dumpedidall [-s | folderpath]
		agdcdevicedump filepath
	
	Miscellaneous functions
		translateoui oui # AGDCDiagnose DisplayPort registers and EDIDs may have an oui.
		translatevendor pnp # a 15 bit value or a 3 character ASCII code.

	Variables
		dodump # Set to 1 to dump the EDID while changes are made to the EDID.
		debug # Set to 1 to output debugging info (uses stderr)
		DisplayIDblocks # An array of DisplayID blocks that are used in the EDID. Save these using something like saveDisplayIDblocks=(\$DisplayIDblocks) before modifying the EDID.
		ctablocks # An array of CTA data blocks that are used in the EDID. Save these using something like savectablocks=(\$ctablocks) before modifying the EDID.
		ctadescriptors # An array of CTA descriptors that are used in the EDID. Save these using something like savectadescriptors=(\$ctadescriptors) before modifying the EDID.
		thetimings # a list of detailed timings (printf "%s\\n" "\${thetimings[@]}")
		theproductfile # the name of an override file in the form of DisplayVendorID-%x/DisplayProductID-%x
		themanufacturefile # the name of an override file in the form of DisplayVendorID-%x/DisplayYearManufacture-%d-DisplayWeekManufacture-%d
		...

	Help
		edidhelp
edidhelp_done
}

#edidhelp

#=========================================================================================

I suppose you can't override the EDID if it won't load properly. Does SwitchResX show a display?
Can you attach zipped output from AllRez? It has code to read EDID.
What macOS version are you using?

I was using Catalina when I damaged it, now I can boot from El Capitan (which has Remote Desktop enabled). If you're curious about edid, it's now
ioreg -lw0 -r -c "IODisplayConnect" -d 2 +-o display0 <class IODisplayConnect, id 0x10000068e, registered, matched, active, busy 0 (0 ms), retain 6> | { | } | +-o AppleBacklightDisplay <class AppleBacklightDisplay, id 0x10000068f, registered, matched, active, busy 0 (0 ms), retain 9> { "IOClass" = "AppleBacklightDisplay" "CFBundleIdentifier" = "com.apple.iokit.IOGraphicsFamily" "IOProviderClass" = "IODisplayConnect" "DisplayProductID" = 40100 "IODisplayEDID" = <be0000ffffffff000610a49c0000000016130103802115780ae585a3544f9c260e505400000001010101010101010101010101010101ab22a0a050841a30302036004bcf10000019000000010006103000000000000000000a20000000fe004c544e31353442543038000a20000000fc00436f6c6f72204c43440a20202000ac> "IODisplayPrefsKey" = "IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@0/display0/AppleBacklightDisplay-610-9ca4" "IODisplayGUID" = 436849163854938112 "IOProbeScore" = 3000 "IODisplayParameters" = {"commit"={"reg"=0},"dsyp"={"min"=0,"max"=2,"value"=2},"fade-time3"={"min"=0,"max"=10000,"value"=500},"brightness"={"max"=1024,"min"=0,"value"=769},"brightness-fade"={"min"=0,"max"=1023,"value"=0},"fade-time2"={"min"=0,"max"=10000,"value"=4000},"fade-time1"={"min"=0,"max"=10000,"value"=500},"usable-linear-brightness"={"min"=452,"max"=1808,"value"=1162},"fade-style"={"min"=0,"max"=10,"value"=0},"linear-brightness"={"min"=0,"max"=1808,"value"=1162}} "IOPowerManagement" = {"DevicePowerState"=3,"CapabilityFlags"=49152,"CurrentPowerState"=3,"MaxPowerState"=3} "IOMatchCategory" = "IODefaultMatchCategory" "IODisplayConnectFlags" = <00080000> "DisplayVendorID" = 1552 "DisplayParameterHandlerUsesCharPtr" = Yes "DisplaySerialNumber" = 0 }
So, it's a wrong header.
Right now I've soldered two wires to the pull-up resistor next to LVDS connector, and my logic analyzer proved the problem: I can see the communication. So now I don't have an i2c programmer at hand (I'm about to order one), and I'm not sure if my programming intervention will be safe for SN74LV4066A, which switches the signal from the PCh(U1800) or that U1800 itself?
Right now, because of those wires, I cannot install and run AllRez.
But even if I cope with overriding EDID, I won't be able to launch from my Catalina disk (which doesn't have Remote Desktop)?

It looks like a valid EDID except the first 3 bytes. The checksum is correct when the first 3 bytes are corrected.

macOS has built-in screen sharing but it needs to be enabled in the Sharing preferences panel before it can be used. Then you can screen share from a different Mac. I think the built in screen sharing may also work as VNC?

If you can't do screen sharing, then you can try connecting an external display.

Another option is to boot into Target Disk Mode but I don't know if that works without the built-in display? When the Mac is in Target Disk Mode, you can connect it to another Mac to use it as a hard drive which you can boot from.

Another option is to remove the hard drive and use it to boot a different Mac.

The display LTN154BT08 or APP9CA4 (vendor:Apple product:9ca4) appears to be this one or similar:
https://www.panelook.com/LTN154BT08-R06_Samsung_15.4_LCM_overview_17497.html

Thanks, I knew all that. I can't connect the external display because of disabled (because faulty) dGPU.
Solved the problem by solderin thin wires directly to the panel cable connector and flashing the EDID.