Extended Display Identification Data

Extended Display Identification Data (EDID) and Enhanced EDID (E-EDID) are metadata formats for display devices to describe their capabilities to a video source (e.g., graphics card or set-top box). The data format is defined by a standard published by the Video Electronics Standards Association (VESA).

The EDID data structure includes manufacturer name and serial number, product type, phosphor or filter type (as chromaticity data), timings supported by the display, display size, luminance data and (for digital displays only) pixel mapping data.

DisplayID is a VESA standard targeted to replace EDID and E-EDID extensions with a uniform format suited for both PC monitor and consumer electronics devices.

Background

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EDID structure (base block) versions range from v1.0 to v1.4; all these define upwards-compatible 128-byte structures. Version 2.0 defined a new 256-byte structure but it has been deprecated and replaced by E-EDID which supports multiple extension blocks.[citation needed] HDMI versions 1.0–1.3c use E-EDID v1.3.[1]

Before Display Data Channel (DDC) and EDID were defined, there was no standard way for a graphics card to know what kind of display device it was connected to. Some VGA connectors in personal computers provided a basic form of identification by connecting one, two or three pins to ground, but this coding was not standardized.

This problem is solved by EDID and DDC, as it enables the display to send information to the graphics card it is connected to. The transmission of EDID information usually uses the Display Data Channel protocol, specifically DDC2B, which is based on I²C-bus (DDC1 used a different serial format which never gained popularity). The data is transmitted via the cable connecting the display and the graphics card; VGA, DVI, DisplayPort and HDMI are supported.[citation needed]

The EDID is often stored in the monitor in the firmware chip called serial EEPROM (electrically erasable programmable read-only memory) and is accessible via the I²C-bus at address 0x50. The EDID PROM can often be read by the host PC even if the display itself is turned off.

Many software packages can read and display the EDID information, such as read-edid[2] for Linux and DOS, PowerStrip[3] for Microsoft Windows and the X.Org Server for Linux and BSD unix. Mac OS X natively reads EDID information and programs such as SwitchResX[4] or DisplayConfigX[5] can display the information as well as use it to define custom resolutions.

E-EDID was introduced at the same time as E-DDC, which supports multiple extensions blocks and deprecated EDID version 2.0 structure (it can be incorporated in E-EDID as an optional extension block). Data fields for preferred timing, range limits, and monitor name are required in E-EDID. E-EDID also adds support for the Dual GTF curve concept and partially changed the encoding of aspect ratio within the standard timings.

With the use of extensions, E-EDID structure can be extended up to 32 KiB, because the E-DDC added the capability to address multiple (up to 128) 256 byte segments.

EDID Extensions assigned by VESA

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  • Timing Extension (00)
  • Additional Timing Data Block (CTA EDID Timing Extension) (02)
  • Video Timing Block Extension (VTB-EXT) (10)
  • EDID 2.0 Extension (20)
  • Display Information Extension (DI-EXT) (40)
  • Localized String Extension (LS-EXT) (50)
  • Microdisplay Interface Extension (MI-EXT) (60)
  • Display ID Extension (70)
  • Display Transfer Characteristics Data Block (DTCDB) (A7, AF, BF)
  • Block Map (F0)
  • Display Device Data Block (DDDB) (FF): contains information such as subpixel layout[6]
  • Extension defined by monitor manufacturer (FF): According to LS-EXT, actual contents varies from manufacturer. However, the value is later used by DDDB.

Revision history

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  • August 1994, DDC standard version 1 – introduce EDID v1.0.
  • April 1996, EDID standard version 2 – introduce EDID v1.1.
  • November 1997, EDID standard version 3 – introduce EDID v1.2 and EDID v2.0.
  • September 1999, E-EDID Standard Release A – introduce EDID v1.3 and E-EDID v1.0, which supports multiple extensions blocks.
  • February 2000, E-EDID Standard Release A - introduce E-EDID v1.3 (used in HDMI), based on EDID v1.3. EDID v2.0 deprecated.
  • September 2006, E-EDID Standard Release A – introduce E-EDID v1.4, based on EDID v1.4.

Limitations

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Some graphics card drivers have historically coped poorly with the EDID, using only its standard timing descriptors rather than its Detailed Timing Descriptors (DTDs). Even in cases where the DTDs were read, the drivers are/were still often limited by the standard timing descriptor limitation that the horizontal/vertical resolutions must be evenly divisible by 8. This means that many graphics cards cannot express the native resolutions of the most common widescreen flat-panel displays and liquid-crystal display TVs. The number of vertical pixels is calculated from the horizontal resolution and the selected aspect ratio. To be fully expressible, the size of widescreen display must thus be a multiple of 16×9 pixels. For 1366×768 pixel Wide XGA panels the nearest resolution expressible in the EDID standard timing descriptor syntax is 1360×765 pixels, typically leading to 3-pixel-thin black bars. Specifying 1368 pixels as the screen width would yield an unnatural screen height of 769.5 pixels.

Many Wide XGA panels do not advertise their native resolution in the standard timing descriptors, instead offering only a resolution of 1280×768. Some panels advertise a resolution only slightly smaller than the native, such as 1360×765. For these panels to be able to show a pixel perfect image, the EDID data must be ignored by the display driver or the driver must correctly interpret the DTD and be able to resolve resolutions whose size is not divisible by 8. Special programs are available to override the standard timing descriptors from EDID data. Even this is not always possible, as some vendors' graphics drivers (notably those of Intel) require specific registry hacks to implement custom resolutions, which can make it very difficult to use the screen's native resolution.[7]

EDID 1.4 data format

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Structure, version 1.4

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EDID structure, version 1.4[8][9]
Bytes Description
0–19 Header information
0–7 Fixed header pattern: 00 FF FF FF FF FF FF 00
8–9 Manufacturer ID. This is a legacy Plug and Play ID assigned by UEFI forum, which is a big-endian 16-bit value made up of three 5-bit letters: 00001, A; 00010, B; ...; 11010, Z. E.g.: 24 4d, 0 01001 00010 01101, "IBM"; "PHL" (Philips).
Bit 15 0 = reserved
Bits 14–10 First letter of manufacturer ID (byte 8, bits 6–2)
Bits 9–5 Second letter of manufacturer ID (byte 8, bit 1 through byte 9 bit 5)
Bits 4–0 Third letter of manufacturer ID (byte 9 bits 4–0)
10–11 Manufacturer product code. 16-bit hex number, little-endian. For Example, "PHL" + "C0CF".
12–15 Serial number. 32 bits, little-endian.
16 Week of manufacture; or FF model year flag. Week numbering is not consistent between manufacturers.
17 Year of manufacture, or year of model, if model year flag is set. Year = datavalue + 1990.
18 EDID version, usually 01 (for 1.3 and 1.4)
19 EDID revision, usually 03 (for 1.3) or 04 (for 1.4)
20–24 Basic display parameters
20 Video input parameters bitmap
Bit 7 = 1 Digital input. If set, the following bit definitions apply:
Bits 6–4 Bit depth:

000 = undefined
001 = 6
010 = 8
011 = 10
100 = 12
101 = 14
110 = 16 bits per color
111 = reserved

Bits 3–0 Video interface:

0000 = undefined
0001 = DVI
0010 = HDMIa
0011 = HDMIb
0100 = MDDI
0101 = DisplayPort

Bit 7 = 0 Analog input. If clear, the following bit definitions apply:
Bits 6–5 Video white and sync levels, relative to blank:

00 = +0.7/−0.3 V
01 = +0.714/−0.286 V
10 = +1.0/−0.4 V
11 = +0.7/0 V (EVC)

Bit 4 Blank-to-black setup (pedestal) expected
Bit 3 Separate sync supported
Bit 2 Composite sync (on HSync) supported
Bit 1 Sync on green supported
Bit 0 VSync pulse must be serrated when composite or sync-on-green is used.
21 Horizontal screen size, in centimetres (range 1–255). If vertical screen size is 0, landscape aspect ratio (range 1.00–3.54), datavalue = (AR×100) − 99 (example: 16:9, 79; 4:3, 34.)
22 Vertical screen size, in centimetres. If horizontal screen size is 0, portrait aspect ratio (range 0.28–0.99), datavalue = (100/AR) − 99 (example: 9:16, 79; 3:4, 34.) If both bytes are 0, screen size and aspect ratio are undefined (e.g. projector)
23 Display gamma, factory default (range 1.00–3.54), datavalue = (gamma×100) − 100 = (gamma − 1)×100. If 255, gamma is defined by DI-EXT block.
24 Supported features bitmap
Bit 7 DPMS standby supported
Bit 6 DPMS suspend supported
Bit 5 DPMS active-off supported
Bits 4–3 Display type (digital):

00 = RGB 4:4:4
01 = RGB 4:4:4 + YCrCb 4:4:4
10 = RGB 4:4:4 + YCrCb 4:2:2
11 = RGB 4:4:4 + YCrCb 4:4:4 + YCrCb 4:2:2

Display type (analog):

00 = monochrome or grayscale
01 = RGB color
10 = non-RGB color
11 = undefined

Bit 2 Standard sRGB colour space. Bytes 25–34 must contain sRGB standard values.
Bit 1 Preferred timing mode specified in descriptor block 1. For EDID 1.3+ the preferred timing mode is always in the first Detailed Timing Descriptor. In that case, this bit specifies whether the preferred timing mode includes native pixel format and refresh rate.
Bit 0 Continuous timings with GTF or CVT
25–34 Chromaticity coordinates.
10-bit 2° CIE 1931 xy coordinates for red, green, blue, and white point
25 Red and green least-significant bits (2−9, 2−10)
Bits 7–6 Red x value least-significant 2 bits
Bits 5–4 Red y value least-significant 2 bits
Bits 3–2 Green x value least-significant 2 bits
Bits 1–0 Green y value least-significant 2 bits
26 Blue and white least-significant 2 bits
27 Red x value most significant 8 bits (2−1, ..., 2−8). 0–255 encodes fractional 0–0.996 (255/256); 0–0.999 (1023/1024) with lsbits
28 Red y value most significant 8 bits
29–30 Green x and y value most significant 8 bits
31–32 Blue x and y value most significant 8 bits
33–34 Default white point x and y value most significant 8 bits
35–37 Established timing bitmap. Supported bitmap for (formerly) very common timing modes.
35 Bit 7 720×400 @ 70 Hz (VGA)
Bit 6 720×400 @ 88 Hz (XGA)
Bit 5 640×480 @ 60 Hz (VGA)
Bit 4 640×480 @ 67 Hz (Apple Macintosh II)
Bit 3 640×480 @ 72 Hz
Bit 2 640×480 @ 75 Hz
Bit 1 800×600 @ 56 Hz
Bit 0 800×600 @ 60 Hz
36 Bit 7 800×600 @ 72 Hz
Bit 6 800×600 @ 75 Hz
Bit 5 832×624 @ 75 Hz (Apple Macintosh II)
Bit 4 1024×768 @ 87 Hz, interlaced (1024×768i)
Bit 3 1024×768 @ 60 Hz
Bit 2 1024×768 @ 70 Hz
Bit 1 1024×768 @ 75 Hz
Bit 0 1280×1024 @ 75 Hz
37 Bit 7 1152x870 @ 75 Hz (Apple Macintosh II)
Bits 6–0 Other manufacturer-specific display modes
38–53 Standard timing information. Up to 8 2-byte fields describing standard display modes.
Unused fields are filled with 01 01 hex. The following definitions apply in each record:
38 Standard timing 1: X resolution, 00 = reserved; otherwise, (datavalue + 31) × 8 (256–2288 pixels).
39 Bits 7–6 Standard timing 1: Image aspect ratio:

00 = 16:10
01 = 4:3
10 = 5:4
11 = 16:9
(Versions prior to 1.3 defined 00 as 1:1.)

Bits 5–0 Vertical frequency, datavalue + 60 (60–123 Hz)
40-41 Standard timing 2
42-43 Standard timing 3
44-45 Standard timing 4
46-47 Standard timing 5
48-49 Standard timing 6
50-51 Standard timing 7
52-53 Standard timing 8
54–125 Display timing descriptor followed by display/monitor descriptors
54–71 Preferred timing descriptor 18 byte detailed timing descriptors or display descriptors
72–89 Descriptor 2
90–107 Descriptor 3
108–125 Descriptor 4
126-127 Extension flag and checksum
126 Number of extensions to follow. 0 if no extensions.
127 Checksum. Sum of all 128 bytes should equal 0 (mod 256).

Detailed Timing Descriptor

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EDID Detailed Timing Descriptor[8]
Bytes Description
0–1 Pixel clock. 00 = reserved; otherwise in 10 kHz units (0.01–655.35 MHz, little-endian).
2 Horizontal active pixels 8 lsbits (0–255)
3 Horizontal blanking pixels 8 lsbits (0–255) End of active to start of next active.
4 Bits 7–4 Horizontal active pixels 4 msbits (0–15)
Bits 3–0 Horizontal blanking pixels 4 msbits (0–15)
5 Vertical active lines 8 lsbits (0–255)
6 Vertical blanking lines 8 lsbits (0–255)
7 Bits 7–4 Vertical active lines 4 msbits (0–15)
Bits 3–0 Vertical blanking lines 4 msbits (0–15)
8 Horizontal front porch (sync offset) pixels 8 lsbits (0–255) From blanking start
9 Horizontal sync pulse width pixels 8 lsbits (0–255)
10 Bits 7–4 Vertical front porch (sync offset) lines 4 lsbits (0–15)
Bits 3–0 Vertical sync pulse width lines 4 lsbits (0–15)
11 Bits 7–6 Horizontal front porch (sync offset) pixels 2 msbits (0–3)
Bits 5–4 Horizontal sync pulse width pixels 2 msbits (0–3)
Bits 3–2 Vertical front porch (sync offset) lines 2 msbits (0–3)
Bits 1–0 Vertical sync pulse width lines 2 msbits (0–3)
12 Horizontal image size, mm, 8 lsbits (0–255 mm, 161 in)
13 Vertical image size, mm, 8 lsbits (0–255 mm, 161 in)
14 Bits 7–4 Horizontal image size, mm, 4 msbits (0–15)
Bits 3–0 Vertical image size, mm, 4 msbits (0–15)
15 Horizontal border pixels (one side; total is twice this) (0–255)
16 Vertical border lines (one side; total is twice this) (0–255)
17 Features bitmap
Bit 7 Signal Interface Type:

0 = non-interlaced;
1 = interlaced.

Bits 6–5 Stereo mode (combine bits 6–5 with bit 0):

00 x = none, bit 0 is "don't care";
01 0 = field sequential, right during stereo sync;
10 0 = field sequential, left during stereo sync;
01 1 = 2-way interleaved, right image on even lines;
10 1 = 2-way interleaved, left image on even lines;
11 0 = 4-way interleaved;
11 1 = side-by-side interleaved.

Bit 4 = 0 Analog sync.
If set, the following bit definitions apply:
Bit 3 Sync type:

0 = analog composite;
1 = bipolar analog composite.

Bit 2 Serration:

0 = without serrations;
1 = with serrations (H-sync during V-sync).

Bit 1 Sync on red and blue lines additionally to green

0 = sync on green signal only;
1 = sync on all three (RGB) video signals.

Bits 4–3 = 10 Digital sync., composite (on HSync).
If set, the following bit definitions apply:
Bit 2 Serration

0 = without serration;
1 = with serration (H-sync during V-sync).

Bit 1 Horizontal sync polarity:

0 = negative;
1 = positive.

Bits 4–3 = 11 Digital sync., separate
If set, the following bit definitions apply:
Bit 2 Vertical sync polarity:

0 = negative;
1 = positive.

Bit 1 Horizontal sync polarity:

0 = negative;
1 = positive.

Bit 0 Stereo mode (combines with bits 6–5)

When used for another descriptor, the pixel clock and some other bytes are set to 0:

Monitor Descriptors

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EDID Monitor Descriptors[8]
Bytes Description
0–1 0 = Monitor Descriptor (cf. Detailed Timing Descriptor).
2 0 = reserved
3 Descriptor type. FA–FF currently defined. 00–0F reserved for vendors.
4 0 = reserved, except for Display Range Limits Descriptor.
5–17 Defined by descriptor type. If text, code page 437 text, terminated (if less than 13 bytes) with LF and padded with SP.

Currently defined descriptor types are:

  • FF: Monitor serial number (ASCII text)
  • FE: Unspecified text (ASCII text)
  • FD: Monitor range limits. 6- or 13-byte (with additional timing) binary descriptor.
  • FC: Monitor name (ASCII text), for example "PHL 223V5".
  • FB: Additional white point data. 2× 5-byte descriptors, padded with 0A 20 20.
  • FA: Additional standard timing identifiers. 6× 2-byte descriptors, padded with 0A.
  • F9: Display Color Management (DCM).
  • F8: CVT 3-Byte Timing Codes.
  • F7: Additional standard timing 3.
  • 10: Dummy identifier.
  • 00–0F: Manufacturer reserved descriptors.

Display Range Limits

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Descriptor

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EDID Display Range Limits Descriptor[8]
Bytes Description
0–1 00 00 = Display Descriptor
2 00 = reserved
3 FD = Display Range Limits Descriptor
4 Offsets for display range limits
Bits 7–4 00 = reserved
Bits 3–2 Horizontal rate offsets:

00 = none;
10 = +255 kHz for max. rate;
11 = +255 kHz for max. and min. rates.

Bits 1–0 Vertical rate offsets:

00 = none;
10 = +255 Hz for max. rate;
11 = +255 Hz for max. and min. rates.

5 Minimum vertical field rate (1–255 Hz; 256–510 Hz, if offset).
6 Maximum
7 Minimum horizontal line rate (1–255 kHz; 256–510 kHz, if offset).
8 Maximum
9 Maximum pixel clock rate, rounded up to 10 MHz multiple (10–2550 MHz).
10 Extended timing information type:

00 = Default GTF (when basic display parameters byte 24, bit 0 is set).
01 = No timing information.
02 = Secondary GTF supported, parameters as follows.
04 = CVT (when basic display parameters byte 24, bit 0 is set), parameters as follows.

11–17 Video timing parameters (if byte 10 is 00 or 01, padded with 0A 20 20 20 20 20 20).

With GTF secondary curve

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EDID Display Range Limits with GTF Secondary curve[8]
Bytes Description
10 02
11 00 = reserved
12 Start frequency for secondary curve, divided by 2 kHz (0–510 kHz)
13 GTF C value, multiplied by 2 (0–127.5)
14–15 GTF M value (0–65535, little-endian)
16 GTF K value (0–255)
17 GTF J value, multiplied by 2 (0–127.5)

With CVT support

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EDID Display Range Limits with CVT support[8]
Bytes Description
10 04
11 Bits 7–4 CVT major version (1–15)
Bits 3–0 CVT minor version (0–15)
12 Bits 7–2 Additional clock precision in 0.25 MHz increments
(to be subtracted from byte 9 maximum pixel clock rate)
Bits 1–0 Maximum active pixels per line, 2-bit msb
13 Maximum active pixels per line, 8-bit lsb (no limit if 0)
14 Aspect ratio bitmap
Bit 7 4∶3
Bit 6 16∶9
Bit 5 16∶10
Bit 4 5∶4
Bit 3 15∶9
Bits 2–0 000 = reserved
15 Bits 7–5 Aspect ratio preference:

000 = 4∶3
001 = 16∶9
010 = 16∶10
011 = 5∶4
100 = 15∶9

Bit 4 CVT-RB reduced blanking (preferred)
Bit 3 CVT standard blanking
Bits 2–0 000 = reserved
16 Scaling support bitmap
Bit 7 Horizontal shrink
Bit 6 Horizontal stretch
Bit 5 Vertical shrink
Bit 4 Vertical stretch
Bits 3–0 0000 = reserved
17 Preferred vertical refresh rate (1–255)

Additional white point descriptor

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EDID additional white point descriptor[8]
Bytes Description
0–4 00 00 00 FB 00
5 White point index number (1–255). Usually 1; 0 indicates descriptor not used.
6 White point CIE xy coordinates least-significant bits (like EDID byte 26)
Bits 7–4 000 = reserved
Bits 3–2 White point x value least-significant 2 bits
Bits 1–0 White point y value least-significant 2 bits
7 White point x value most significant 8 bits (like EDID byte 27)
8 White point y value most significant 8 bits (like EDID byte 28)
9 datavalue = (gamma − 1)×100 (1.0–3.54, like EDID byte 23)
10–14 Second descriptor. Index number starts with 2; if 0 = unused
15–17 Unused, padded with 0A 20 20.

Color management data descriptor

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EDID color management data descriptor[8]
Bytes Description
0–4 00 00 00 F9 00
5 Version: 03
6 Red a3 lsb
7 Red a3 msb
8 Red a2 lsb
9 Red a2 msb
10 Green a3 lsb
11 Green a3 msb
12 Green a2 lsb
13 Green a2 msb
14 Blue a3 lsb
15 Blue a3 msb
16 Blue a2 lsb
17 Blue a2 msb

CVT 3-byte timing codes descriptor

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EDID CVT 3-byte timing codes descriptor[8]
Bytes Description
0–4 00 00 00 F8 00
5 Version: 01
6-8 CVT timing descriptor #1
6 Addressable lines per field 8-bit lsb
7 Bits 7–4 Addressable lines per field 4-bit msb
Bits 3–2 Aspect ratio:

00 = 4∶3
01 = 16∶9
10 = 16∶10
11 = 15∶9

Bits 1–0 00 = reserved
8 Bit 7 0 = reserved
Bits 6–5 Preferred vertical rate:

00: 50 Hz
01: 60 Hz
10: 75 Hz
11: 85 Hz

Vertical rate bitmap
Bit 4 50 Hz CVT
Bit 3 60 Hz CVT
Bit 2 75 Hz CVT
Bit 1 85 Hz CVT
Bit 0 60 Hz CVT reduced blanking
9–11 CVT timing descriptor #2
12–14 CVT timing descriptor #3
15–17 CVT timing descriptor #4


Additional standard timings

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EDID Additional standard timings 3[8]
Bytes Description
0–4 00 00 00 F7 00
5 Version: 10
6 Bit 7 640×350 @ 85 Hz
Bit 6 640×400
Bit 5 720×400
Bit 4 640×480
Bit 3 848×480 @ 60 Hz
Bit 2 800×600 @ 85 Hz
Bit 1 1024×768
Bit 0 1152×864
7 Bit 7 1280×768 @ 60 Hz (CVT-RB)
Bit 6 @ 60 Hz
Bit 5 @ 75 Hz
Bit 4 @ 85 Hz
Bit 3 1280×960 @ 60 Hz
Bit 2 @ 85 Hz
Bit 1 1280×1024 @ 60 Hz
Bit 0 @ 85 Hz
8 Bit 7 1360×768 @ 60 Hz (CVT-RB)
Bit 6 1280×768 @ 60 Hz
Bit 5 1440×900 @ 60 Hz (CVT-RB)
Bit 4 @ 75 Hz
Bit 3 @ 85 Hz
Bit 2 1400×1050 @ 60 Hz (CVT-RB)
Bit 1 @ 60 Hz
Bit 0 @ 75 Hz
9 Bit 7 @ 85 Hz
Bit 6 1680×1050 @ 60 Hz (CVT-RB)
Bit 5 @ 60 Hz
Bit 4 @ 75 Hz
Bit 3 @ 85 Hz
Bit 2 1600×1200 @ 60 Hz
Bit 1 @ 65 Hz
Bit 0 @ 70 Hz
10 Bit 7 @ 75 Hz
Bit 6 @ 85 Hz
Bit 5 1792×1344 @ 60 Hz
Bit 4 @ 75 Hz
Bit 3 1856×1392 @ 60 Hz
Bit 2 @ 75 Hz
Bit 1 1920×1200 @ 60 Hz (CVT-RB)
Bit 0 @ 60 Hz
11 Bit 7 @ 75 Hz
Bit 6 @ 85 Hz
Bit 5 1920×1440 @ 60 Hz
Bit 4 @ 75 Hz
Bits 3–0 0000 = reserved
12–17 Unused, must be 0.

CTA EDID Timing Extension Block

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The CTA EDID Extension was first introduced in EIA/CEA-861.

CTA-861 Standard

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The ANSI/CTA-861 industry standard, which according to CTA is now their "Most Popular Standard",[10] has since been updated several times, most notably with the 861-B revision (published in May 2002, which added version 3 of the extension, adding Short Video Descriptors and advanced audio capability/configuration information), 861-D (published in July 2006 and containing updates to the audio segments), 861-E in March 2008,[11] 861-F, which was published on June 4, 2013,[12] 861-H in December 2020,[13] and, most recently, 861-I, which was published in February 2023.[14] Coinciding with the publication of CEA-861-F in 2013, Brian Markwalter, senior vice president, research and standards, stated: "The new edition includes a number of noteworthy enhancements, including support for several new Ultra HD and widescreen video formats and additional colorimetry schemes.”[15]

Version CTA-861-G,[16] originally published in November 2016, was made available for free in November 2017, along with updated versions -E and -F, after some necessary changes due to a trademark complaint. All CTA standards are free to everyone since May 2018.[17][18]

The most recent full version is CTA-861-I,[19] published in February 2023, available for free after registration. It combines the previous version, CTA-861-H,[20] from January 2021 with an amendment, CTA-861.6,[21] published in February 2022 and includes a new formula to calculate Video Timing Formats, OVT.[22] Other changes include a new annex to elaborate on the audio speaker room configuration system that was introduced with the 861.2 amendment, and some general clarifications and formatting cleanup.

An amendment to CTA-861-I, CTA-861.7,[23] was published in June 2024. It contains updates to CTA 3D Audio, and clarifications on Content Type Indication, and on 4:2:0 support for VTDBs and VFDBs. It also introduces a new Product ID Data Block, to replace the Manufacturer PNP ID in the first block of the EDID, since the UEFI is phasing out assigning new PNP IDs.

CTA Extension Block

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Version 1 of the extension block (as defined in CEA−861) allowed the specification of video timings only through the use of 18-byte Detailed Timing Descriptors (DTD) (as detailed in EDID 1.3 data format above). DTD timings are listed in order of preference in the CEA EDID Timing Extension.

Version 2 (as defined in 861-A) added the capability to designate a number of DTDs as "native" (i.e., matching the resolution of the display) and also included some "basic discovery" functionality for whether the display device contains support for "basic audio", YCBCR pixel formats, and underscan.

Version 3 (from the 861-B spec onward) allows two different ways to specify digital video timing formats: As in Version 1 & 2 by the use of 18-byte DTDs, or by the use of the Short Video Descriptor (SVD) (see below). HDMI 1.0–1.3c uses this[which?] version.

Version 3 also defines a format for a collection of data blocks, which in turn can contain a number of individual descriptors. This Data Block Collection (DBC) initially had four types of Data Blocks (DBs): Video Data Blocks containing the aforementioned Short Video Descriptor (SVD), Audio Data Blocks containing Short Audio Descriptors (SAD), Speaker Allocation Data Blocks containing information about the speaker configuration of the display device, and Vendor Specific Data Blocks which can contain information specific to a given vendor's use. Subsequent versions of CTA-861 defined additional data blocks.

CTA Extension data format

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Byte Description
0 Extension tag (which kind of extension block this is); 02 for CTA EDID
1 Revision number (version number); 03 for version 3
2 Byte number (decimal) within this block where the 18-byte DTDs begin. If no non-DTD data is present in this extension block, the value should be set to 04 (the byte after next). If set to 00, there are no DTDs present in this block and no non-DTD data.
3 With version 2 and up: number of Native DTDs present, other information. Reserved with earlier versions.
Bit 7 1 if display supports underscan, 0 if not
Bit 6 1 if display supports basic audio, 0 if not
Bit 5 1 if display supports YCBCR 4∶4∶4, 0 if not
Bit 4 1 if display supports YCBCR 4∶2∶2, 0 if not
Bit 3–0 Total number of native formats in the DTDs included in this block
4–126 With version 3 and up: Data Block Collection, starting at byte 4, ending immediately before the byte specified in byte 2. If byte 2 is 04, the collection is of zero length (i.e. not present). If byte 2 is 00, no DTDs are present and the DBC takes up the entire remaining EDID block ahead of the checksum. Reserved with earlier versions.
18-byte descriptors, starting at the byte specified in byte 2 (if non-zero). Consecutive descriptors are present while the bytes 0–1 of each are not 00 00.
Padding, from the absence of an 18-byte descriptor onwards; must be 00.
127 Checksum. Value such that the one-byte sum of all 128 bytes is 00.

The Data Block Collection contains one or more data blocks detailing video, audio, and speaker placement information about the display. The blocks can be placed in any order, and the initial byte of each block defines both its type and its length:

Data block header
Byte Description
0 Bit 7–5 Block Type Tag
  • 001 1: Audio (ADB, containing SADs)
  • 010 2: Video (VDB, containing SVDs)
  • 011 3: Vendor Specific (VSDB)
  • 100 4: Speaker Allocation (SADB)
  • 101 5: VESA Display Transfer Characteristic (VESA DTCDB)
  • 110 6: Video Format (VFDB, containing VFDs)
  • 111 7: Use Extended Tag
Bit 4–0 Total number of bytes in this block following this byte.

If the Tag code is 7, an Extended Tag Code is present in the first payload byte of the data block, and the second payload byte represents the first payload byte of the extended data block.

Extended Block Type Tag
Byte Description
1 Bit 7–0 Extended Block Type Tag
  • 00000000 0: Video Capability (VCDB)
  • 00000001 1: Vendor Specific Video (VSVDB)
  • 00000010 2: VESA Display Device (VESA DDDB)
  • 00000011 3: reserved for VESA
  • 00000100 4: reserved for HDMI
  • 00000101 5: Colorimetry (CDB)
  • 00000110 6: HDR Static Metadata (HDR SMDB)
  • 00000111 7: HDR Dynamic Metadata (HDR DMDB)
  • 00001000 8: Native Video Resolution (NVRDB)
  • 9-12: reserved for video
  • 00001101 13: Video Format Preference (VFPDB)
  • 00001110 14: YCBCR 4:2:0 Video (Y420VDB)
  • 00001111 15: YCBCR 4:2:0 Capability Map (Y420CMDB)
  • 00010000 16: reserved for CTA (CTA MAF)
  • 00010001 17: Vendor Specific Audio (VSADB)
  • 00010010 18: HDMI Audio (HDMI ADB)
  • 00010011 19: Room Configuration (RCDB)
  • 00010100 20: Speaker Location (SLDB, containing SLDs)
  • 21-31: reserved for audio
  • 00100000 32: InfoFrame (IFDB)
  • 00100001 33: reserved
  • 00100010 34: Type VII video timing (T7VTDB)
  • 00100011 35: Type VIII video timing (T8VTDB)
  • 36-41: reserved
  • 00101010 42: Type X video timing (T10VTDB)
  • 42-119: reserved
  • 01111000 120: HDMI Forum EDID Extension Override (HF-EEODB)
  • 01111001 121: HDMI Forum Sink Capbility (HF-SCDB)
  • 01111010 122: HDMI Forum Source-Based Tone Mapping (HF-SBTMDB)
  • 123-127: reserved for HDMI
  • else: reserved

Once one data block has ended, the next byte is assumed to be the beginning of the next data block. This is the case until the byte (designated in byte 2, above) where the DTDs are known to begin.

CTA Data Blocks

[edit]

As noted, several data blocks are defined by the extension.

Video Data Blocks

[edit]

The Video Data Blocks will contain one or more 1-byte Short Video Descriptors (SVDs).

Byte Description
0 Data block header
1 Bit 7 1 to designate that this should be considered a "native" resolution, 0 for non-native. Used for 7-bit VICs 1 – 64 only, otherwise this is the MSB for the 8-bit VIC.
Bit 6–0 VIC: Index value to a table of standard resolutions/timings from EIA/CEA-861:
EIA/CEA-861 predefined standard resolutions and timings
[edit]
EIA/CEA-861 standard resolutions and timings
VIC Short name Aspect ratio Clock Active Total Field rate (Hz)
DAR PAR Pixel (MHz) V (Hz) H (kHz) H V H V
1 DMT0659 4∶3 1∶1 25.175 59.94 31.469 640 480 800 525 60
2 480p 4∶3 8∶9 27 59.94 31.469 720 480 858 525 60
3 480pH 16∶9 32∶27 27 59.94 31.469 720 480 858 525 60
4 720p 16∶9 1∶1 74.25 60 45.0 1280 720 1650 750 60
5 1080i 16∶9 1∶1 74.25 60 33.75 1920 540 2200 562.5 60
6 480i 4∶3 8∶9 27 59.94 15.734 1440 240 1716 262.5 60
7 480iH 16∶9 32∶27 27 59.94 15.734 1440 240 1716 262.5 60
8 240p 4∶3 4∶9 27 59.826 15.734 1440 240 1716 262.5 60
9 240pH 16∶9 16∶27 27 59.826 15.734 1440 240 1716 262.5 60
10 480i4x 4∶3 2:9-20:9 54 59.94 15.734 2880 240 3432 262.5 60
11 480i4xH 16∶9 8:27-80:27 54 59.94 15.734 2880 240 3432 262.5 60
12 240p4x 4∶3 1:9-10:9 54 60 15.734 2880 240 3432 262.5 60
13 240p4xH 16∶9 4:27-40:27 54 60 15.734 2880 240 3432 262.5 60
14 480p2x 4∶3 4:9, 8∶9 54 59.94 31.469 1440 480 1716 525 60
15 480p2xH 16∶9 16:27, 32∶27 54 59.94 31.469 1440 480 1716 525 60
16 1080p 16∶9 1∶1 148.5 60 67.5 1920 1080 2200 1125 60
17 576p 4∶3 16∶15 27 50 31.25 720 576 864 625 50
18 576pH 16∶9 64∶45 27 50 31.25 720 576 864 625 50
19 720p50 16∶9 1∶1 74.25 50 37.5 1280 720 1980 750 50
20 1080i25 16∶9 1∶1 74.25 50 28.125 1920 540 2640 562.5 50
21 576i 4∶3 16∶15 27 50 15.625 1440 288 1728 312.5 50
22 576iH 16∶9 64∶45 27 50 15.625 1440 288 1728 312.5 50
23 288p 4∶3 8∶15 27 50 15.625 1440 288 1728 313 50
24 288pH 16∶9 32∶45 27 50 15.625 1440 288 1728 313 50
25 576i4x 4∶3 2:15-20:15 54 50 15.625 2880 288 3456 312.5 50
26 576i4xH 16∶9 16:45-160:45 54 50 15.625 2880 288 3456 312.5 50
27 288p4x 4∶3 1:15-10:15 54 50 15.625 2880 288 3456 313 50
28 288p4xH 16∶9 8:45-80:45 54 50 15.625 2880 288 3456 313 50
29 576p2x 4∶3 8:15, 16∶15 54 50 31.25 1440 576 1728 625 50
30 576p2xH 16∶9 32:45, 64∶45 54 50 31.25 1440 576 1728 625 50
31 1080p50 16∶9 1∶1 148.5 50 56.25 1920 1080 2640 1125 50
32 1080p24 16∶9 1∶1 74.25 23.98/24 27 1920 1080 2750 1125 Low
33 1080p25 16∶9 1∶1 74.25 25 28.125 1920 1080 2640 1125 Low
34 1080p30 16∶9 1∶1 74.25 29.97/30 33.75 1920 1080 2200 1125 Low
35 480p4x 4∶3 2:9, 4:9, 8∶9 108 59.94 31.469 2880 240 3432 262.5 60
36 480p4xH 16∶9 8:27, 16:27, 32∶27 108 59.94 31.469 2880 240 3432 262.5 60
37 576p4x 4∶3 4:15, 8:15, 16∶15 108 50 31.25 2880 576 3456 625 50
38 576p4xH 16∶9 16:45, 32:45, 64∶45 108 50 31.25 2880 576 3456 625 50
39 1080i25 16∶9 1∶1 72 50 31.25 1920 540 2304 625 50
40 1080i50 16∶9 1∶1 148.5 100 56.25 1920 540 2640 562.5 100
41 720p100 16∶9 1∶1 148.5 100 45.0 1280 720 1980 750 100
42 576p100 4∶3 16∶15 54 100 62.5 720 576 864 625 100
43 576p100H 16∶9 64∶45 54 100 62.5 720 576 864 625 100
44 576i50 4∶3 16∶15 54 100 31.25 1440 576 1728 625 100
45 576i50H 16∶9 64∶45 54 100 31.25 1440 576 1728 625 100
46 1080i60 16∶9 1∶1 148.5 119.88/120 67.5 1920 540 2200 562.5 120
47 720p120 16∶9 1∶1 148.5 119.88/120 90.0 1280 720 1650 750 120
48 480p119 4∶3 8∶9 54 119.88/120 62.937 720 480 858 525 120
49 480p119H 16∶9 32∶27 54 119.88/120 62.937 720 480 858 525 120
50 480i59 4∶3 16∶15 54 119.88/120 31.469 1440 480 1716 525 120
51 480i59H 16∶9 64∶45 54 119.88/120 31.469 1440 480 1716 525 120
52 576p200 4∶3 16∶15 108 200 125.0 720 576 864 625 200
53 576p200H 16∶9 64∶45 108 200 125.0 720 576 864 625 200
54 576i100 4∶3 16∶15 108 200 62.5 1440 288 1728 312.5 200
55 576i100H 16∶9 64∶45 108 200 62.5 1440 288 1728 312.5 200
56 480p239 4∶3 8∶9 108 239.76 125.874 720 480 858 525 240
57 480p239H 16∶9 32∶27 108 239.76 125.874 720 480 858 525 240
58 480i119 4∶3 8∶9 108 239.76 62.937 1440 240 1716 262.5 240
59 480i119H 16∶9 32∶27 108 239.76 62.937 1440 240 1716 262.5 240
60 720p24 16∶9 1∶1 59.4 23.98/24 18.0 1280 720 3300 750 Low
61 720p25 16∶9 1∶1 74.25 25 18.75 1280 720 3960 750 Low
62 720p30 16∶9 1∶1 74.25 29.97/30 22.5 1280 720 3300 750 Low
63 1080p120 16∶9 1∶1 297 119.88/120 135.0 1920 1080 2200 1125 120
64 1080p100 16∶9 1∶1 297 100 112.5 1920 1080 2640 1125 100
65 720p24 64∶27 4∶3 59.4 23.98/24 18.0 1280 720 3300 750 Low
66 720p25 64∶27 4∶3 74.25 25 18.75 1280 720 3960 750 Low
67 720p30 64∶27 4∶3 74.25 29.97/30 22.5 1280 720 3300 750 Low
68 720p50 64∶27 4∶3 74.25 50 37.5 1280 720 1980 750 50
69 720p 64∶27 4∶3 74.25 60 45.0 1650 750 1650 750 60
70 720p100 64∶27 4∶3 148.5 100 75.0 1280 720 1980 750 100
71 720p120 64∶27 4∶3 148.5 119.88/120 90.0 1280 720 1650 750 120
72 1080p24 64∶27 4∶3 74.25 23.98/24 27 1920 1080 2750 1125 Low
73 1080p25 64∶27 4∶3 74.25 25 28.125 1920 1080 2640 1125 Low
74 1080p30 64∶27 4∶3 74.25 29.97/30 33.75 1920 1080 2200 1125 Low
75 1080p50 64∶27 4∶3 148.5 50 56.25 1920 1080 2640 1125 50
76 1080p 64∶27 4∶3 148.5 60 67.5 1920 1080 2200 1125 60
77 1080p100 64∶27 4∶3 297.0 100 112.5 1920 1080 2640 1125 100
78 1080p120 64∶27 4∶3 297.0 119.88/120 135.0 1920 1080 2200 1125 120
79 720p2x24 64∶27 64∶63 59.4 23.98/24 18.0 1680 720 3300 750 Low
80 720p2x25 64∶27 64∶63 59.4 25 18.75 1680 720 3168 750 Low
81 720p2x30 64∶27 64∶63 59.4 29.97/30 22.5 1680 720 2640 750 Low
82 720p2x50 64∶27 64∶63 82.5 50 37.5 1680 720 2200 750 50
83 720p2x 64∶27 64∶63 99 60 45.0 1680 720 2200 750 60
84 720p2x100 64∶27 64∶63 165 100 82.5 1680 720 2000 825 100
85 720p2x120 64∶27 64∶63 198 119.88/120 99.0 1680 720 2000 825 120
86 1080p2x24 64∶27 1∶1 99 23.98/24 26.4 2560 1080 3750 1100 Low
87 1080p2x25 64∶27 1∶1 90 25 28.125 2560 1080 3200 1125 Low
88 1080p2x30 64∶27 1∶1 118.8 29.97/30 33.75 2560 1080 3520 1125 Low
89 1080p2x50 64∶27 1∶1 185.625 50 56.25 2560 1080 3000 1125 50
90 1080p2x 64∶27 1∶1 198 60 66.0 2560 1080 3000 1100 60
91 1080p2x100 64∶27 1∶1 371.25 100 125.0 2560 1080 2970 1250 100
92 1080p2x120 64∶27 1∶1 495 119.88/120 150.0 2560 1080 3300 1250 120
93 2160p24 16∶9 1∶1 297 23.98/24 54 3840 2160 5500 2250 Low
94 2160p25 16∶9 1∶1 297 25 56.25 3840 2160 5280 2250 Low
95 2160p30 16∶9 1∶1 297 29.97/30 67.5 3840 2160 4400 2250 Low
96 2160p50 16∶9 1∶1 594 50 112.5 3840 2160 5280 2250 50
97 2160p60 16∶9 1∶1 594 60 135.0 3840 2160 4400 2250 60
98 2160p24 256∶135 1∶1 297 23.98/24 67.5 4096 2160 5500 2250 Low
99 2160p25 256∶135 1∶1 297 25 112.5 4096 2160 5280 2250 Low
100 2160p30 256∶135 1∶1 297 29.97/30 135.0 4096 2160 4400 2250 Low
101 2160p50 256∶135 1∶1 594 50 112.5 4096 2160 5280 2250 50
102 2160p 256∶135 1∶1 594 60 135.0 4096 2160 4400 2250 60
103 2160p24 64∶27 4∶3 297 23.98/24 67.5 3840 2160 5500 2250 Low
104 2160p25 64∶27 4∶3 297 25 112.5 3840 2160 5280 2250 Low
105 2160p30 64∶27 4∶3 297 29.97/30 135.0 3840 2160 4400 2250 Low
106 2160p50 64∶27 4∶3 594 50 112.5 3840 2160 5280 2250 50
107 2160p 64∶27 4∶3 594 60 135.0 3840 2160 4400 2250 60
108 720p48 16∶9 1∶1 90 47.96/48 36.0 1280 720 2500 750 Low
109 720p48 64∶27 4∶3 90 47.96/48 36.0 1280 720 2500 750 Low
110 720p2x48 64∶27 64∶63 99 47.96/48 36.0 1680 720 2750 825 Low
111 1080p48 16∶9 1∶1 148.5 47.96/48 54 1920 1080 2750 1125 Low
112 1080p48 64∶27 4∶3 148.5 47.96/48 54 1920 1080 2750 1125 Low
113 1080p2x48 64∶27 1∶1 198 47.96/48 52.8 2560 1080 3750 1100 Low
114 2160p48 16∶9 1∶1 594 47.96/48 108 3840 2160 5500 2250 Low
115 2160p48 256∶135 1∶1 594 47.96/48 108 4096 2160 5500 2250 Low
116 2160p48 64∶27 4∶3 594 47.96/48 108 3840 2160 5500 2250 Low
117 2160p100 16∶9 1∶1 1188 100 225.0 3840 2160 5280 2250 100
118 2160p120 16∶9 1∶1 1188 119.88/120 270.0 3840 2160 4400 2250 120
119 2160p100 64∶27 4∶3 1188 100 225.0 3840 2160 5280 2250 100
120 2160p120 64∶27 4∶3 1188 119.88/120 270.0 3840 2160 4400 2250 120
121 2160p2x24 64∶27 1∶1 396 23.98/24 52.8 5120 2160 7500 2200 Low
122 2160p2x25 64∶27 1∶1 396 25 55.0 5120 2160 7200 2200 Low
123 2160p2x30 64∶27 1∶1 396 29.97/30 66.0 5120 2160 6000 2200 Low
124 2160p2x48 64∶27 1∶1 742.5 47.96/48 118.8 5120 2160 6250 2450 Low
125 2160p2x50 64∶27 1∶1 742.5 50 112.5 5120 2160 6600 2250 50
126 2160p2x 64∶27 1∶1 742.5 60 135.0 5120 2160 5500 2250 60
127 2160p2x100 64∶27 1∶1 1485 100 225.0 5120 2160 6600 2250 100
128—192 reserved, value range is used in SVD to indicate native timing for numbers 1—64.
193 2160p2x120 64∶27 1∶1 1485.0 119.88/120 270 5120 2160 5500 2250 120
194 4320p24 16∶9 1∶1 1188.0 23.98/24 108 7680 4320 11000 4500 Low
195 4320p25 16∶9 1∶1 1188.0 25 110 7680 4320 10800 4400 Low
196 4320p30 16∶9 1∶1 1188.0 29.97/30 132 7680 4320 9000 4400 Low
197 4320p48 16∶9 1∶1 2376.0 47.96/48 216 7680 4320 11000 4500 Low
198 4320p50 16∶9 1∶1 2376.0 50 220 7680 4320 10800 4400 50
199 4320p 16∶9 1∶1 2376.0 60 264 7680 4320 9000 4400 60
200 4320p100 16∶9 1∶1 4752.0 100 450 7680 4320 10560 4500 100
201 4320p120 16∶9 1∶1 4752.0 119.88/120 540 7680 4320 8800 4500 120
202 4320p24 64∶27 4∶3 1188.0 23.98/24 108 7680 4320 11000 4500 Low
203 4320p25 64∶27 4∶3 1188.0 25 110 7680 4320 10800 4400 Low
204 4320p30 64∶27 4∶3 1188.0 29.97/30 132 7680 4320 9000 4400 Low
205 4320p48 64∶27 4∶3 2376.0 47.96/48 216 7680 4320 11000 4500 Low
206 4320p50 64∶27 4∶3 2376.0 50 220 7680 4320 10800 4400 50
207 4320p 64∶27 4∶3 2376.0 60 264 7680 4320 9000 4400 60
208 4320p100 64∶27 4∶3 4752.0 100 450 7680 4320 10560 4500 100
209 4320p120 64∶27 4∶3 4752.0 119.88/120 540 7680 4320 8800 4500 120
210 4320p2x24 64∶27 1∶1 1485.0 23.98/24 118.8 10240 4320 12500 4950 Low
211 4320p2x25 64∶27 1∶1 1485.0 25 110 10240 4320 13500 4400 Low
212 4320p2x30 64∶27 1∶1 1485.0 29.97/30 135 10240 4320 11000 4500 Low
213 4320p2x48 64∶27 1∶1 2970.0 47.96/48 237.6 10240 4320 12500 4950 Low
214 4320p2x50 64∶27 1∶1 2970.0 50 220 10240 4320 13500 4400 50
215 4320p2x 64∶27 1∶1 2970.0 60 270 10240 4320 11000 4400 60
216 4320p2x100 64∶27 1∶1 5940.0 100 450 10240 4320 13200 4500 100
217 4320p2x120 64∶27 1∶1 5940.0 119.88/120 540 10240 4320 11000 4500 120
218 2160p100 256∶135 1∶1 1188.0 100 225 4096 2160 5280 2250 100
219 2160p120 256∶135 1∶1 1188.0 119.88/120 270 4096 2160 4400 2250 120

Notes: Parentheses indicate instances where pixels are repeated to meet the minimum speed requirements of the interface. For example, in the 720x240p case, the pixels on each line are double-clocked. In the (2880)x480i case, the number of pixels on each line, and thus the number of times that they are repeated, is variable, and is sent to the DTV monitor by the source device.

Increased Hactive expressions include “2x” and “4x” indicate two and four times the reference resolution, respectively.

Video modes with vertical refresh frequency being a multiple of 6 Hz (i.e. 24, 30, 60, 120, and 240 Hz) are considered to be the same timing as equivalent NTSC modes where vertical refresh is adjusted by a factor of 1000/1001. As VESA DMT specifies 0.5% pixel clock tolerance, which 5 times more than the required change, pixel clocks can be adjusted to maintain NTSC compatibility; typically, 240p, 480p, and 480i modes are adjusted, while 576p, 576i and HDTV formats are not.

  • The EIA/CEA-861 and 861-A standards included only numbers 1–7 and numbers 17–22 (only in -A) above (but not as short video descriptors which were introduced in EIA/CEA-861-B) and are considered primary video format timings.
  • The EIA/CEA-861-B standard has the first 34 short video descriptors above. It is used by HDMI 1.0–1.2a.
  • The EIA/CEA-861-C and -D standards have the first 59 short video descriptors above. EIA/CEA-861-D is used by HDMI 1.3–1.3c.
  • The EIA/CEA-861-E standard has the first 64 short video descriptors above. It is used by HDMI 1.4–1.4b.
  • The CTA-861-F standard has the first 107 short video descriptors above. It is used by HDMI 2.0–2.0b.
  • The CTA-861-G standard has the full list of 154 (1–127, 193–219) short video descriptors above. It is used by HDMI 2.1.

Audio Data Blocks

[edit]

The Audio Data Blocks contain one or more 3-byte Short Audio Descriptors (SADs). Each SAD details audio format, channel number, and bitrate/resolution capabilities of the display as follows:

Short Audio Descriptor
Byte Description
0 Data block header
1 Format and number of channels:
Bit 7 Reserved, 0
Bit 6–3 Audio format code
Bit 2–0 Number of channels minus 1
  • 000 1 channel
  • 001 2 channels
  • 010 3 channels
  • 011 4 channels
  • 100 5 channels
  • 101 6 channels
  • 110 7 channels
  • 111 8 channels
2 Sampling frequencies (kHz) supported:
Bit 7 Reserved, 0
Bit 6 192
Bit 5 176
Bit 4 96
Bit 3 88
Bit 2 48
Bit 1 44.1
Bit 0 32
3 Bitrate / format dependent:
For codec 1, LPCM:
Bits 7–3 Reserved
Bit 2 24-bit depth
Bit 1 20-bit depth
Bit 0 16-bit depth
For audio format codecs 2–8, the maximum supported bitrate in bit/s, divided by 8000.
For audio format codecs 9–14, format dependent value.
For audio format codec 15 (Extension):
Bit 7–3 Audio format extended code
Bits 2–0 format dependent value

Vendor Specific Data Block

[edit]

A Vendor Specific Data Block (if any) contains as its first three bytes the vendor's IEEE 24-bit registration number,[24] least significant byte first. The remainder of the Vendor Specific Data Block is the "data payload", which can be anything the vendor considers worthy of inclusion in this EDID extension block. For example, IEEE registration number 00 0C 03 means this is a "HDMI Licensing, LLC" specific data block (contains HDMI 1.4 info), C4 5D D8 means this is a "HDMI Forum" specific data block (contains HDMI 2.0 info), 00 D0 46 means this is "DOLBY LABORATORIES, INC." (contains Dolby Vision info) and 90 84 8b is "HDR10+ Technologies, LLC" (contains HDR10+ info as part of HDMI 2.1 Amendment A1 standard[25]). It starts with a two byte source physical address, least significant byte first. The source physical address provides the CEC physical address for upstream CEC devices. HDMI 1.3a specifies some requirements for the data payload.

Vendor Specific Data Block for "HDMI Licensing LLC"
Byte Description
0 Data block header
1–3 IEEE Registration Identifier (little endian)
4–5 Components of Source Physical Address[26]
6 (optional) 1, supported; 0, unsupported:
Bit 7 A function that needs info from ACP or ISRC packets
Bit 6 16-bit-per-channel deep color (48-bit)
Bit 5 12-bit-per-channel deep color (36-bit)
Bit 4 10-bit-per-channel deep color (30-bit)
Bit 3 4∶4∶4 in deep color modes
Bit 2 Reserved, 0
Bit 1 Reserved, 0
Bit 0 DVI Dual Link Operation
7 (optional) Maximum TMDS frequency. 0, unspecified; else, Max_TMDS_Frequency / 5 MHz
8 (optional) Latency fields indicators 1, present; 0, absent:
Bit 7 Latency fields
Bit 6 Interlaced latency fields. Absent if latency fields are absent.
Bits 5–0 Reserved, 0
9 Video latency optional; if indicated, value = 1 + ms/2 with a max. of 251 meaning 500 ms
10 Audio latency
(video delay for progressive sources)
11 Interlaced video latency
12 Interlaced audio latency
(video delay for interlaced sources)
13+ Additional bytes may be present, but the HDMI spec. says they shall be 00.

Speaker Allocation Data Block

[edit]

If a Speaker Allocation Data Block is present, it will consist of three bytes. The first and second bytes contain information about which speakers (or speaker pairs) are present in the display device:

Speaker Allocation Data Block
Byte Description
0 Data block header
1 1, present; 0, absent:
Bit 7 Front left/right wide (FLw/FRw)
Bit 6 Deprecated, was Rear left/right center (RLC/RRC)
Bit 5 Front left/right center (FLc/FRc)
Bit 4 Back center (BC)
Bit 3 Back left/right (BL/BR)
Bit 2 Front center (FC)
Bit 1 Low-frequency effects (LFE)
Bit 0 Front left/right (FL/FR)
2
Bit 7 Deprecated, was Top side left/right (TpSiL/TpSiR)
Bit 6 Deprecated, was Side left/right (SiL/SiR)
Bit 5 Deprecated, was Top back center (TpBC)
Bit 4 Deprecated, was Low-frequency effects 2 (LFE2)
Bit 3 Left surround/right surround (LS/RS)
Bit 2 Top front center (TpFC)
Bit 1 Top center (TpC)
Bit 0 Top front left/right (TpFL/TpFR)
3 Bits 7-3 Reserved, 0
Bit 2 Deprecated, was Bottom front left/right (BtFL/BtFR)
Bit 1 Deprecated, was Bottom front center (BtFC)
Bit 0 Deprecated, was Top back left/right (TpBL/TpBR)

Some speaker flags have been deprecated in the SADB, but are still available in the RCDB's SPM. These speakers could not be indicated with a CA value in the Audio InfoFrame, and can only be used with Delivery According to the Speaker Mask, which corresponds to the RCDB only.

Room Configuration Data Block

[edit]

The Room Configuration Data Block and Speaker Location Data Blocks describe the speaker setup using room coordinates.

Room Configuration Data Block
Byte Description
0 Data block header
Bits 7-5 111=7, block type tag
Bits 4-0 Length of payload data that follows this block, in bytes
1 13 = extended tag code
3 Configuration
Bit 7 Display data is valid
Bit 6 Speaker count is valid
Bit 5 Speaker location descriptors (SLD) are present
Bits 4-0 Speaker count (1-32)
4 Speaker presence mask 1 (SPM1): 1, present; 0, absent
Bit 7 Front left/right wide (FLw/FRw)
Bit 6 Deprecated, was Rear left/right center (RLC/RRC)
Bit 5 Front left/right center (FLc/FRc)
Bit 4 Back center (BC)
Bit 3 Back left/right (BL/BR)
Bit 2 Front center (FC)
Bit 1 Low-frequency effects 1 (LFE1)
Bit 0 Front left/right (FL/FR)
5 Speaker presence mask 2 (SPM2): 1, present; 0, absent
Bit 7 Top side left/right (TpSiL/TpSiR)
Bit 6 Side left/right (SiL/SiR)
Bit 5 Top back center (TpBC)
Bit 4 Low-frequency effects 2 (LFE2)
Bit 3 Left/right surround (LS/RS)
Bit 2 Top front center (TpFC)
Bit 1 Top center (TpC)
Bit 0 Top front left/right (TpFL/TpFR)
6 Speaker presence mask 3 (SPM3): 1, present; 0, absent
Bits 7-4 Reserved, 0
Bit 3 Deprecated, was Top left/right surround (TpLS/TpRS)
Bit 2 Bottom front left/right (BtFL/BtFR)
Bit 1 Bottom front center (BtFC)
Bit 0 Top back left/right (TpBL/TpBR)
7-9 Maximum distance from the primary listening position to the farthest speakers along X, Y, Z axes, if speaker location descriptors (SLD) blocks are present; otherwise 00 = undefined
10-13 Distance from the primary listening position to the center of display along X, Y, Z axes; 00 = undefined when display data flag is not set

References

[edit]
  1. ^ "High-Definition Multimedia Interface Specification Version 1.3a" (PDF). 10 November 2006. Archived from the original (PDF) on 5 March 2016. Retrieved 2017-04-01.
  2. ^ "read-edid". Polypux.org. Archived from the original on 2010-12-11. Retrieved 2017-04-01.
  3. ^ "Utilities | PowerStrip". EnTech Taiwan. 2012-03-25. Archived from the original on 2011-03-08. Retrieved 2017-04-01.
  4. ^ "SwitchResX - The Most Versatile Tool For Controlling Screen Resolutions On Your Mac". Madrau.com. Archived from the original on 2009-02-08. Retrieved 2017-04-01.
  5. ^ Harald Schweder (2003-02-11). "DisplayConfigX". 3dexpress.de. Archived from the original on 2011-07-18. Retrieved 2017-04-01.
  6. ^ "VESA Display Device Data Block (DDDB) Standard" (PDF). github.io. 25 September 2006. Archived (PDF) from the original on 2021-04-17.
  7. ^ Brezenski (2009-08-07). "Custom Resolutions on Intel Graphics". Software.intel.com. Archived from the original on 2011-03-15. Retrieved 2009-11-04.
  8. ^ a b c d e f g h i j VESA E-EDID Standard, Release A, Revision 2. September 25, 2006 Archived November 11, 2020, at the Wayback Machine;
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  26. ^ see section 8.7 of HDMI 1.3a
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