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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 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:

VIC code.
is the actual HDMI VIC code.
DisplayID Video Timing Modes Types I, II, VI and VII. The number denotes that this is the Nth DTD in the EDID.

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

OPTIONS

Prints the help message.
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
Check if the EDID conforms to the standards. Warnings and failures are reported at the end.
Check if the EDID conforms to the standards. Warnings and failures are reported as they happen.
Report the native timings at the end. There may be multiple native 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).
Report the preferred timings at the end. There may be multiple native 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).
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.
Report all video timings in a short format.
Report all video timings in a long format.
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.
Report all long video timings in the video mode format as defined in fb.modes(5).
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.
Skip the initial hex dump of the EDID.
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.
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.
Show the SHA hash and the last commit date.

NOTES

Not all fields are decoded, or decoded completely. Some fields' decoding may appear to corrupt the output (for example, detailed string sections have their contents printed literally). 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