Provided by: edid-decode_0.1~git20220315.cb74358c2896-1_amd64 
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 2.1: VESA DisplayID Standard, Version 2.1
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 2.1: 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 Interfaces
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 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 2.0: 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 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).
--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.
--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 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. For complete history and the latest version, see
http://git.linuxtv.org/cgit.cgi/edid-decode.git
edid-decode(1)