EDID-DECODE(1)			 User Commands			EDID-DECODE(1)

NAME
       edid-decode - Decode EDID data in human-readable format

SYNOPSIS
       edid-decode <options> [in [out]]

DESCRIPTION
       edid-decode decodes EDID monitor description data in human-readable
       format.	If [in] is not given, or [in] is '-', then the EDID will be
       read from standard input. If [out] is given then the EDID that was read
       from [in] is written to [out] or to standard output if [out] is '-'. By
       default the output is written as a hex dump when writing to standard
       output or a raw EDID if written to a file.

       If [out] is given then edid-decode only does the conversion, it will
       skip the decoding step.

       Input files may be raw binaries or ASCII text.  ASCII input is scanned
       for hex dumps; heuristics are included to search for hexdumps in
       edid-decode(1) output (as long as the initial hex dump was included),
       xrandr(1) property output and Xorg(1) log file formats, otherwise the
       data is treated as a raw hexdump.  EDID blocks for connected monitors
       can be found in /sys/class/drm/*/edid on modern Linux systems with
       kernel modesetting support.

       All timings are shown in a short format, for example:

	   VIC	16:  1920x1080	 60.000 Hz  16:9    67.500 kHz 148.500 MHz
       (native)
	   VIC	 5:  1920x1080i	 60.000 Hz  16:9    33.750 kHz	74.250 MHz
	   VIC	39:  1920x1080i	 50.000 Hz  16:9    31.250 kHz	72.000 MHz

       Each format starts with a timings type prefix, the resolution, an
       optional interlaced indicator ('i'), the frame rate (field rate for
       interlaced formats), the picture aspect ratio, the horizontal
       frequency, the pixelclock frequency and optionally additional flags
       between parenthesis.

       Note that for interlaced formats the frame height is given, not the
       field height. So each field in a 1920x1080i format has 540 lines.

       Detailed timings have another 2-3 lines of data:

	   VIC	16:  1920x1080	 60.000 Hz  16:9    67.500 kHz 148.500 MHz
       (native)
			  Hfront   88 Hsync  44 Hback 148 Hpol P
			  Vfront    4 Vsync   5 Vback  36 Vpol P
	   VIC	 5:  1920x1080i	 60.000 Hz  16:9    33.750 kHz	74.250 MHz
			  Hfront   88 Hsync  44 Hback 148 Hpol P
			  Vfront    2 Vsync   5 Vback  15 Vpol P Vfront +0.5
       Odd Field
			  Vfront    2 Vsync   5 Vback  15 Vpol P Vback	+0.5
       Even Field
	   VIC	39:  1920x1080i	 50.000 Hz  16:9    31.250 kHz	72.000 MHz
			  Hfront   32 Hsync 168 Hback 184 Hpol P
			  Vfront   23 Vsync   5 Vback  57 Vpol N Both Fields

       These describe the horizontal and vertical front porch, sync, backporch
       and sync polarity values. For interlaced formats there are two lines
       for the vertical information: one for the Odd Field (aka Field 1) and
       one for the Even Field (aka Field 2). The vertical front porch of the
       Odd Field is actually 2.5 (hence the 'Vfront +0.5' at the end of the
       line), and the back porch of the Even Field is actually 15.5 (hence the
       'Vback  +0.5' at the end of the line).

       There is a special 'VIC 39' interlaced format where both fields have
       the same vertical timings, in that case this is marked with 'Both
       Fields'.

       The following timing types can be shown:


	      DMT #: Discrete Monitor Timing (see DMT 1.3 standard). The
	      number is the DMT ID in hexadecimal.

	      CVT: Coordinated Video Timings (formula-based, see CVT 1.2
	      standard)

	      GTF: Generalized Timing Formula (formula-based, see GTF 1.1
	      standard)

	      IBM: Old IBM Timings

	      Apple: Old Apple Timings

	      VIC #: Video Identification Code (see CTA-861 standard). The
	      number is the actual
		     VIC code.

	      HDMI VIC #: HDMI-specific Video Identification Code (see HDMI
	      2.1 standard). The number
		     is the actual HDMI VIC code.

	      DTD #: Detailed Timings Descriptor (see EDID standard). Also
	      used for
		     DisplayID Video Timing Modes Types I, II, VI, VII, VIII
		     and X. The number denotes that this is the Nth DTD in the
		     Base Block and CTA Extension Blocks.

	      VTDB #: 20-byte DTD or 6- or 7-byte CVT descriptor in a CTA
	      Extension Block.
		     The number denotes that this is the Nth such timing in
		     the CTA Extension Blocks.

	      RID #@#: A CTA-861.6 Video Format Descriptor with the given
	      Resolution ID (first
		     number) at the given framerate (second number).

       By default DTDs are shown in the long format while others are just
       shown in the short format. With the option --short-timings all timings
       are shown in short format only. With the option --long-timings all
       timings are shown in long format.

       Alternate formats for long timings can be chosen via the --xmodeline or
       --fbmode options.


STANDARDS
       The following EDID standards are supported by edid-decode:

	      EDID 1.3: VESA Enhanced Extended Display Identication Data
	      Standard, Release A, Revision 1

	      EDID 1.4: VESA Enhanced Extended Display Identication Data
	      Standard, Release A, Revision 2

	      DisplayID 1.3: VESA Display Identification Data (DisplayID)
	      Standard, Version 1.3

	      DisplayID 2.1a: VESA DisplayID Standard, Version 2.1a

	      DI-EXT: VESA Display Information Extension Block Standard,
	      Release A

	      LS-EXT: VESA Enhanced EDID Localized String Extension Standard,
	      Release A

	      VTB-EXT: VESA Video Timing Block Extension Data Standard,
	      Release A

	      DTCDB: VESA Display Transfer Characteristics Data Block
	      Standard, Version 1.0

	      DDDB: VESA Display Device Data Block (DDDB) Standard, Version 1

	      HDMI 1.4b: High-Definition Multimedia Interface, Version 1.4b

	      HDMI 2.1b: High-Definition Multimedia Interface, Version 2.1b

	      HDCP 1.4: High-bandwidth Digital Content Protection System,
	      Revision 1.4

	      HDCP 2.3: High-bandwidth Digital Content Protection System,
	      Mapping HDCP to HDMI, Revision 2.3

	      CTA-861-I: A DTV Profile for Uncompressed High Speed Digital
	      Interfaces

	      CTA-861.7: Improvements to CTA-861-I

	      SPWG Notebook Panel Specification, Version 3.5

	      EPI Embedded Panel Interface, Revision 1.0

	      Microsoft EDID extension for head-mounted and specialized
	      monitors, Version 3


       The following related standards are also used by edid-decode:

	      DMT 1.3: VESA and Industry Standards and Guidelines for Computer
	      Display Monitor Timing (DMT), Version 1.0, Rev. 13

	      CVT 2.1: VESA Coordinated Video Timings (CVT) Standard, Version
	      2.1

	      CVT 1.2: VESA Coordinated Video Timings (CVT) Standard, Version
	      1.2

	      CVT 1.2: VESA CVT v1.2 Errata E2

	      GTF 1.1: VESA Generalized Timing Formula Standard, Version: 1.1

	      HDA 1.0a: High Definition Audio Specification, Version 1.0a


OPTIONS
       -h, --help
	      Prints the help message.

       -o, --output-format <fmt>
	      If [out] is specified, then write the EDID in format <fmt>.

	      The output format can be one of:
	      hex: hex numbers in ascii text (default for stdout)
	      raw: binary data (default unless writing to stdout)
	      carray: c-program struct
	      xml: XML data

       -c, --check
	      Check if the EDID conforms to the standards. Warnings and
	      failures are reported at the end.

       -C, --check-inline
	      Check if the EDID conforms to the standards. Warnings and
	      failures are reported as they happen.

       -n, --native-resolution
	      Report the native resolution at the end. There may be multiple
	      native resolution reports depending on whether the Source only
	      parses Block 0 (e.g. DVI outputs) or Block 0 and the CTA-861
	      Extension Blocks (HDMI), or just the DisplayID Extension Blocks
	      (typical for DisplayPort). If all blocks contain the same native
	      resolution, then only that resolution is reported. For older
	      displays there may be two separate native resolutions:
	      progressive and interlaced.

       -p, --preferred-timings
	      Report the preferred timings at the end. There may be multiple
	      preferred timing reports depending on whether the Source only
	      parses Block 0 (e.g. DVI outputs), or Block 0 and the CTA-861
	      Extension Blocks (HDMI), or Block 0 and the DisplayID Extension
	      Blocks (typical for DisplayPort).

       -I, --infoframe <file>
	      Parse the given InfoFrame file. This option can be used multiple
	      times to parse multiple InfoFrames. If the EDID of the display
	      to which these InfoFrames are transmitted is also given, then
	      the conformity checks will take that EDID into account.

	      If the first byte in the InfoFrame is 0x80 or higher, then it is
	      assumed to be an InfoFrame that starts with the HDMI header and
	      has a checksum, as per the HDMI Specification. Otherwise it is
	      assumed to be a regular CTA-861 InfoFrame without a checksum.

	      Note: this is still work-in-progress, specifically for the AVI
	      and HDMI InfoFrames.

       -E, --eld <file>
	      Parse the given EDID-Like Data (ELD) file. This option can be
	      used multiple times to parse multiple ELD files. Read data from
	      stdin if '-' was passed as a filename.  If the EDID of the
	      display to which these ELD files are generated is also given,
	      then the conformity checks will take that EDID into account.

	      On Linux systems ELD can be extracted via the amixer command
	      (copy all hex after the 'values='):
		$ amixer -c 0 controls | grep ELD
		numid=6,iface=PCM,name='ELD',device=3
		numid=12,iface=PCM,name='ELD',device=7
		numid=18,iface=PCM,name='ELD',device=8
		numid=24,iface=PCM,name='ELD',device=9
		$ amixer -c 0 cget iface=PCM,name=ELD,device=3
		numid=6,iface=PCM,name='ELD',device=3
		  ; type=BYTES,access=r--v----,values=95
		  :
	      values=0x10,0x00,0x08,0x00,0x6d,0x10,0x00,0x01,0x00,0x02,0x00,0x00,0x00,0x00,
		  0x00,0x00,0x30,0xae,0xf1,0x61,0x4c,0x45,0x4e,0x20,0x54,0x33,0x32,0x68,0x2d,0x32,
		  0x30,0x0a,0x20,0x09,0x7f,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00


       --diagonal <inches>
	      Specify the diagonal of the display in inches. This will enable
	      additional checks for the image size, checking if it corresponds
	      to the diagonal. This assumes square pixels.

       -P, --physical-address
	      Just report the HDMI Source Physical Address and nothing else.
	      Reports f.f.f.f if the EDID could not be parsed, or if there was
	      no CTA-861 Vendor-Specific Data Block with OUI 00-0C-03.
	      Otherwise it reports the Source Physical Address as provided in
	      that Data Block. This can be used as input to HDMI CEC utilities
	      such as the linux cec-ctl(1) utility.

       -S, --short-timings
	      Report all video timings in a short format.

       -L, --long-timings
	      Report all video timings in a long format.

       -N, --ntsc
	      Report the video timings with values suitable for NTSC-based
	      video.  E.g., this will show refresh rates of 29.97 Hz instead
	      of 30 Hz.	 This is only done for timings with refresh rates that
	      are a multiple of 6.

       -X, --xmodeline
	      Report all long video timings in the ModeLine format as defined
	      in xorg.conf(5).	This ModeLine can be used in the xorg.conf
	      file or passed to xrandr(1) with the xrandr --newmode option.

       -F, --fbmode
	      Report all long video timings in the video mode format as
	      defined in fb.modes(5).

       -V, --v4l2-timings
	      Report all long video timings in the video mode format as
	      defined in the linux header v4l2-dv-timings.h for use with the
	      V4L2 VIDIOC_S_DV_TIMINGS ioctl.

       -s, --skip-hex-dump
	      Skip the initial hex dump of the EDID.

       -H, --only-hex-dump
	      Only show the hex dump of the EDID, then exit.

       --skip-sha
	      Don't show the SHA hash. Normally edid-decode will show the SHA,
	      i.e. the hash of the git commit used to compile edid-decode.
	      This uniquely identifies the version of edid-decode that is used
	      to generate the warnings and failures. But it will also change
	      the output of edid-decode for every new commit in the git
	      repository, even if nothing else changed in the edid-decode
	      output.  Use this option to avoid including the SHA in the edid-
	      decode output.

       -u, --utf8
	      Convert embedded EDID strings to UTF-8, using Code Page 437 for
	      the base block and ISO 8859-1 for the DisplayID block.

       --hide-serial-numbers
	      Hide any serial numbers in the human readable output by '...'.
	      Note that they are still easily extracted from the EDID hex dump
	      at the start.

       --replace-unique-ids
	      Replaces any unique IDs in the EDID by fixed values. Serial
	      numbers will be replaced by '123456', Container IDs by all
	      zeroes and the 'Made in' date by the year 2000. This will also
	      update any checksums in the EDID and update the EDID hex dump at
	      the start of the output. Note that since this will update
	      checksums, any checksum errors present in the original EDID will
	      no longer be detected.

	      Serial numbers can appear in the Base Block, CTA-861 Extension
	      Blocks, DisplayID Extension Blocks and Localized String
	      Extension Blocks.	 Container IDs can appear in the DisplayID and
	      CTA-861 Extension Blocks.

	      The 'Made in' date appears in the Base Block.

       --version
	      Show the SHA hash and the last commit date.


I2C/DDC OPTIONS
       The following options read the DDC bus directly, provided the DDC bus
       is exposed by linux to /dev/i2c-X as an i2c adapter device.

       This can be used to read the EDID and HDCP information directly from
       the sink and parse it.

       -a, --i2c-adapter <dev>
	      Use the <dev> device to access the DDC lines.  If <dev> starts
	      with a digit, then /dev/i2c-<dev> is used.

       --i2c-edid
	      Read and parse the EDID from the i2c adapter.

       --i2c-hdcp
	      Read and parse the HDCP data from the i2c adapter.

       --i2c-hdcp-ri <t>
	      Every <t> seconds read and report the HDCP Ri value from the i2c
	      adapter.

       --i2c-test-reliability [duration=<secs>][,sleep=<msecs>]
	      Read the EDID continuously for <secs> seconds (default is 0,
	      meaning forever), with a sleep of <msecs> milliseconds (default
	      value is 50 ms) in between each read. Report a FAIL if there are
	      mismatches between EDIDs. This tests the i2c communication
	      towards the display.


TIMING OPTIONS
       The following options report the timings for DMT, VIC and HDMI VIC
       codes and calculate the timings for CVT or GTF timings, based on the
       given parameters.  The EDID will not be shown, although it can be used
       with the --gtf option in order to read the secondary curve parameters.

       --std <byte1>,<byte2>
	      Show the standard timing represented by these two bytes.

       --dmt <dmt>
	      Show the timings for the DMT with the given DMT ID.

       --vic <vic>
	      Show the timings for this VIC.

       --hdmi-vic <hdmivic>
	      Show the timings for this HDMI VIC.

       --cvt w=<width>,h=<height>,fps=<fps>[,rb=<rb>][,interlaced][,overscan]
	      [,alt][,hblank=<hblank>][,vblank=<vblank>][,early-vsync]
	      Calculate the CVT timings for the given format.

	      <width> is the width in pixels, <height> is the frame (not
	      field!) height in lines.
	      <fps> is frames per second for progressive timings and fields
	      per second for interlaced timings.
	      <rb> can be 0 (no reduced blanking, default), or 1-3 for the
	      reduced blanking version.
	      If interlaced is given, then this is an interlaced format.
	      If overscan is given, then this is an overscanned format. I.e.,
	      margins are required.
	      If alt is given and <rb>=2, then report the timings optimized
	      for video: 1000 / 1001 * <fps>.
	      If alt is given and <rb>=3, then the horizontal blanking is 160
	      instead of 80 pixels.
	      If hblank is given and <rb>=3, then the horizontal blanking is
	      <hblank> pixels (range of 80-200 and divisible by 8), overriding
	      alt.
	      If vblank is given and <rb>=3, then the vertical blanking time
	      is <vblank> microseconds (460 minimum, values > 705 might not be
	      supported by all RBv3 timings compliant source devices.
	      If early-vsync is given and <rb>=3, then select an early vsync
	      timing.

       --gtf
       w=<width>,h=<height>[,fps=<fps>][,horfreq=<horfreq>][,pixclk=<pixclk>]
	      [,interlaced][,overscan][,secondary][,C=<c>][,M=<m>][,K=<k>][,J=<j>]
	      Calculate the GTF timings for the given format.

	      <width> is the width in pixels, <height> is the frame (not
	      field!) height in lines.
	      <fps> is frames per second for progressive timings and fields
	      per second for interlaced timings.
	      <horfreq> is the horizontal frequency in kHz.
	      <pixclk> is the pixel clock frequency in MHz.  Only one of fps,
	      horfreq or pixclk must be given.
	      If interlaced is given, then this is an interlaced format.
	      If overscan is given, then this is an overscanned format. I.e.,
	      margins are required.
	      If secondary is given, then the secondary GTF is used for
	      reduced blanking, where <c>, <m>, <k> and <j> are parameters for
	      the secondary curve.  If none of the secondary curve parameters
	      were set, and an EDID file is passed as command line option,
	      then the secondary curve parameters are read from that EDID.
	      The default secondary curve parameters are 40 for <c>, 600 for
	      <m>, 128 for <k> and 20 for <j>.	These values correspond to the
	      normal curve that GTF uses.

       --ovt (rid=<rid>|w=<width>,h=<height>),fps=<fps>
	      Calculate the OVT timings for the given format.  Either specify
	      a <rid> or specify <width> and <height>.	<fps> is frames per
	      second.

       --list-established-timings
	      List all known Established Timings.

       --list-dmts
	      List all known DMTs.

       --list-vics
	      List all known VICs.

       --list-hdmi-vics
	      List all known HDMI VICs.

       --list-rids
	      List all known CTA-861 RIDs.

       --list-rid-timings <rid>
	      List all timings for the specified <rid> or all known RIDs if
	      <rid> is 0.


NOTES
       Not all fields are decoded, or decoded completely.  edid-decode does
       attempt to validate its input against the relevant standards, but its
       opinions have not been double-checked with the relevant standards
       bodies, so they may be wrong.  Do not rely on the output format, as it
       will likely change in future versions of the tool as additional fields
       and extensions are added.

SEE ALSO
       Xorg(1), xrandr(1), cec-ctl(1), xorg.conf(5), fb.modes(5)

AUTHORS
       edid-decode was written by Adam Jackson, with contributions from Eric
       Anholt, Damien Lespiau, Hans Verkuil and others.

       Bug reports or questions about this utility should be sent to the
       linux-media@vger.kernel.org mailinglist.

v4l-utils 1.30.1		 November 2024			EDID-DECODE(1)