edid-decode(1) General Commands Manual 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 for-
mat. 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 de-
fault the output is written as a hex dump when writing to standard out-
put 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 ker-
nel 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 (na-
tive)
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 op-
tional interlaced indicator ('i'), the frame rate (field rate for inter-
laced formats), the picture aspect ratio, the horizontal frequency, the
pixelclock frequency and optionally additional flags between parenthe-
sis.
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 (na-
tive)
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 stan-
dard)
GTF: Generalized Timing Formula (formula-based, see GTF 1.1 stan-
dard)
IBM: Old IBM Timings
Apple: Old Apple Timings
VIC #: Video Identification Code (see CTA-861 standard). The num-
ber 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 Ex-
tension 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 Reso-
lution 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 Stan-
dard, Release A, Revision 1
EDID 1.4: VESA Enhanced Extended Display Identication Data Stan-
dard, Release A, Revision 2
DisplayID 1.3: VESA Display Identification Data (DisplayID) Stan-
dard, Version 1.3
DisplayID 2.1: VESA DisplayID Standard, Version 2.1
DI-EXT: VESA Display Information Extension Block Standard, Re-
lease 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 2.1: High-Definition Multimedia Interface, Version 2.1
HDMI 2.1: Amendment A1 to HDMI Specification Version 2.1
CTA-861-H: A DTV Profile for Uncompressed High Speed Digital In-
terfaces
CTA-861.6: Improvements on Audio and Video Signaling
SPWG Notebook Panel Specification, Version 3.5
EPI Embedded Panel Interface, Revision 1.0
Microsoft EDID extension for head-mounted and specialized moni-
tors, 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 2.0: VESA Coordinated Video Timings (CVT) Standard, Version
2.0
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
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 fail-
ures are reported at the end.
-C, --check-inline
Check if the EDID conforms to the standards. Warnings and fail-
ures 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 Ex-
tension 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 dis-
plays 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 Ex-
tension Blocks (HDMI), or Block 0 and the DisplayID Extension
Blocks (typical for DisplayPort).
--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. Other-
wise 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 VID-
IOC_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.
--hide-serial-numbers
Replace any serial numbers in the human readable output by '...'.
Note that they are still easily extracted from the EDID hex dump
at the start.
--version
Show the SHA hash and the last commit date.
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 pa-
rameters. 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 re-
duced 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=<pix-
clk>]
[,interlaced][,overscan][,sec-
ondary][,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 sec-
ondary 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 sec-
ond.
--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 at-
tempt to validate its input against the relevant standards, but its
opinions have not been double-checked with the relevant standards bod-
ies, 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. For complete history
and the latest version, see http://git.linuxtv.org/cgit.cgi/edid-de-
code.git
edid-decode(1)
Generated by dwww version 1.16 on Sat Oct 3 05:59:31 CEST 2026.