Using an 8:3 aspect ratio display with Android

dimitarstanev · April 2, 2023, 9:18am

Which system do you use? Android, Ubuntu, OOWOW or others?

Android

Which version of system do you use? Khadas official images, self built images, or others?

Khadas official Android 11 image

Please describe your issue below:

I am trying to make a VIM1S board work with a 8:3 1920x720 display I have. The display model is HSD103KPW2. When I connect it to the board it works and displays the image in fullscreen but it seems to think the native resolution of the display is 1920x1080 (wrong). As a result, everything is skewed and appears wider than it should be.

I already tried changing the resolution via ADB, but without success. If I set 1920x720, additional black borders appear on top and bottom. Also, I don’t see 1920x720 as an option in Khadas settings > Display, just others such as 1080p and 720p.

I saw in other posts that there is a workaround to build my own Android source, but sadly I’m on macOS and it doesn’t seem to be supported as of 2021. Is there any way I could make this work properly? Or maybe some update in the future will address it?

I really didn’t think this was going to be a problem, and I really need this display and to be running Android for my use case. Help will be greatly appreciated!

xiong.zhang · April 3, 2023, 1:27am

@dimitarstanev Hello, I checked that the resolution of 1920x720 is not added in our firmware source code, we can add a new 1920x720HDMI resolution, but there are no display parameters for this resolution, so we need the EDID information of the display
Please use the adb command to get the EDID information and send it to us

adb shell
cat /sys/class/amhdmitx/amhdmitx0/rawedid

Refer to the picture below

Or do you have the manual document of the monitor, you can also share it to me to see if there is any relevant information displayed

dimitarstanev · April 4, 2023, 6:56am

Hi @xiong.zhang, thanks for the help!

Here’s the EDID of the display:

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

xiong.zhang · April 4, 2023, 7:14am

Hello, according to the EDID you sent, the analysis result is as follows, and there is no information about the resolution of the monitor supporting 1920x720.

edid-decode (hex):

00 ff ff ff ff ff ff 00 49 f7 00 00 00 00 00 00
19 1a 01 03 80 00 00 00 0a d7 a5 a2 59 4a 96 24
14 50 54 af ce 00 d1 c0 b3 00 81 00 81 80 81 40
81 c0 01 01 01 01 d1 c0 b3 00 81 00 81 80 81 40
81 c0 01 01 01 01 66 21 50 b0 51 00 1b 30 40 70
36 00 3f 43 21 00 00 1e 00 00 00 fd 00 32 4c 1e
50 10 00 0a 20 20 20 20 20 20 00 00 00 fc 00 41
41 41 0a 20 20 20 20 20 20 20 20 20 01 00 01 45

23 74 4f 10 9f 14 05 04 13 12 16 11 15 03 07 02
06 01 23 09 0f 03 83 01 00 00 66 03 0c 00 10 00
80 01 1d 00 bc 52 d0 1e 20 b8 28 55 40 c4 8e 21
00 00 1e 01 1d 80 d0 72 1c 16 20 10 2c 25 80 c4
8e 21 00 00 9e 8c 0a d0 8a 20 e0 2d 10 10 3e 96
00 13 8e 21 00 00 18 8c 0a d0 90 20 40 31 20 0c
40 55 00 13 8e 21 00 00 18 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 9d 00 05

----------------

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:
    Manufacturer: ROW
    Model: 0
    Made in: week 25 of 2016
  Basic Display Parameters & Features:
    Digital display
    Image size is variable
    Gamma: 1.00
    RGB color display
    First detailed timing is the preferred timing
  Color Characteristics:
    Red  : 0.6357, 0.3486
    Green: 0.2900, 0.5888
    Blue : 0.1425, 0.0800
    White: 0.3134, 0.3291
  Established Timings I & II:
    IBM     :   720x400    70.082 Hz   9:5    31.467 kHz  28.320 MHz
    DMT 0x04:   640x480    59.940 Hz   4:3    31.469 kHz  25.175 MHz
    DMT 0x05:   640x480    72.809 Hz   4:3    37.861 kHz  31.500 MHz
    DMT 0x06:   640x480    75.000 Hz   4:3    37.500 kHz  31.500 MHz
    DMT 0x08:   800x600    56.250 Hz   4:3    35.156 kHz  36.000 MHz
    DMT 0x09:   800x600    60.317 Hz   4:3    37.879 kHz  40.000 MHz
    DMT 0x0a:   800x600    72.188 Hz   4:3    48.077 kHz  50.000 MHz
    DMT 0x0b:   800x600    75.000 Hz   4:3    46.875 kHz  49.500 MHz
    DMT 0x10:  1024x768    60.004 Hz   4:3    48.363 kHz  65.000 MHz
    DMT 0x11:  1024x768    70.069 Hz   4:3    56.476 kHz  75.000 MHz
    DMT 0x12:  1024x768    75.029 Hz   4:3    60.023 kHz  78.750 MHz
  Standard Timings:
    DMT 0x52:  1920x1080   60.000 Hz  16:9    67.500 kHz 148.500 MHz
    DMT 0x3a:  1680x1050   59.954 Hz  16:10   65.290 kHz 146.250 MHz
    DMT 0x1c:  1280x800    59.810 Hz  16:10   49.702 kHz  83.500 MHz
    DMT 0x23:  1280x1024   60.020 Hz   5:4    63.981 kHz 108.000 MHz
    DMT 0x20:  1280x960    60.000 Hz   4:3    60.000 kHz 108.000 MHz
    DMT 0x55:  1280x720    60.000 Hz  16:9    45.000 kHz  74.250 MHz
  Detailed Timing Descriptors:
    DTD 1:  2227x2048   91.316 Hz 2227:2048 198.796 kHz 493.610 MHz (analog composite, sync-on-green, interleaved right even, 1 mm x 257 mm)
                 Hfront  897 Hsync  64 Hback -705 Hpol N Hborder 1
                 Vfront    8 Vsync   1 Vback 120 Vpol N Vborder 102
    DTD 2:   337x1840   75.185 Hz 337:1840 143.153 kHz 451.360 MHz (analog composite, sync-on-green, 33 mm x 0 mm)
                 Hfront  310 Hsync   0 Hback 2506 Hpol N Hborder 30
                 Vfront    3 Vsync  63 Vback  -2 Vpol N
                   50 b0 51 00 1b 30 40 70 36 00 3f 43 21 00 00 1e 00 00 'P.Q..0@p6.?C!.....'
    DTD 3:  1024x286   426.825 Hz 512:143 156.218 kHz 647.680 MHz (analog composite, sync-on-green, 544 mm x 32 mm)
                 Hfront    0 Hsync 522 Hback 2600 Hpol N Hborder 32
                 Vfront    2 Vsync   0 Vback  78 Vpol N
                   00 fd 00 32 4c 1e 50 10 00 0a 20 20 20 20 20 20 00 00 '...2L.P...      ..'
    DTD 4:  1024x577   817.109 Hz 1024:577 479.643 kHz 645.120 MHz (analog composite, sync-on-green, 544 mm x 32 mm)
                 Hfront   32 Hsync 544 Hback -255 Hpol N Hborder 32
                 Vfront    2 Vsync   0 Vback   8 Vpol N Vborder 1
                   00 fc 00 41 41 41 0a 20 20 20 20 20 20 20 20 20 01 00 '...AAA.         ..'
  Extension blocks: 1
Checksum: 0x45

----------------

Block 1, Unknown EDID Extension Block 0x23:
  23 74 4f 10 9f 14 05 04 13 12 16 11 15 03 07 02 '#tO.............'
  06 01 23 09 0f 03 83 01 00 00 66 03 0c 00 10 00 '..#.......f.....'
  80 01 1d 00 bc 52 d0 1e 20 b8 28 55 40 c4 8e 21 '.....R.. .(U@..!'
  00 00 1e 01 1d 80 d0 72 1c 16 20 10 2c 25 80 c4 '.......r.. .,%..'
  8e 21 00 00 9e 8c 0a d0 8a 20 e0 2d 10 10 3e 96 '.!....... .-..>.'
  00 13 8e 21 00 00 18 8c 0a d0 90 20 40 31 20 0c '...!....... @1 .'
  40 55 00 13 8e 21 00 00 18 00 00 00 00 00 00 00 '@U...!..........'
  00 00 00 00 00 00 00 00 00 00 00 00 00 9d 00 05 '................'
Checksum: 0x05

According to what you described, you can take a picture of abnormal display to see

dimitarstanev · April 4, 2023, 7:33am

So it would look like the display was maybe adapted from a 1080p and does not report its own native resolution as supported? Bummer… Or it could be from the driver board itself, since the display only has a LVDS and one other ribbon interface.

Here’s how it looks like (you can clearly see the skewing effect in the image):

xiong.zhang · April 4, 2023, 7:50am

In this way, you use adb to modify the resolution of the UI to see the above effect

adb shell
wm szie 1920x720

dimitarstanev · April 4, 2023, 8:08am

Yes, I’ve already tried that and also all sorts of resolution changer apps (root and non-root). The result is this:

xiong.zhang · April 4, 2023, 8:33am

Or do you have other devices or computers that can display on this monitor?

dimitarstanev · April 4, 2023, 9:35am

Yes, I managed to make it work on a PC running Windows (NVidia graphics) with a “custom resolution” in the NVIDIA control panel.

I suppose these generic displays are not very high quality and this is the reason the native resolution is not reported in the EDID. I will be returning the display as it clearly does not work properly.

Anyway, thank you very much for the help and stay safe!

xiong.zhang · April 4, 2023, 9:42am

You are here to buy this, so do you want to ask the seller about the specifications of this monitor or specific monitor information?

aeozyalcin · December 27, 2023, 6:09am

@xiong.zhang can you offer guidance on how I can get a custom display EDID to work in the Android image on VIM1S?

xiong.zhang · December 27, 2023, 6:23am

Hello, the submissions related to HDMI in the following library: add vesa resolutions support are all, just add the corresponding data.

aeozyalcin · December 28, 2023, 4:23am

Thank you! The display I am trying to get working (I have a separate thread I will tag you in if you want to look at it) uses detailed timing rather than established timing to do 1600x600. I saw that the commits you pointed me to implement the new resolutions using established timings. Any hints for me?

xiong.zhang · December 28, 2023, 6:08am

You can just add the relevant information about the resolution that needs to be added in the commit you submitted, which are some parameters of the monitor. You can get the EDID of the monitor and I will analyze it for you.

cat /sys/class/amhdmitx/amhdmitx0/rawedid

aeozyalcin · December 28, 2023, 8:04pm

Thank you! I posted the rawedid on the other thread I created about this particular display.

aeozyalcin · February 2, 2024, 7:11am

@xiong.zhang happy new year! Just checking to see if you saw my last message. Thank you!