How to add and enable 2K display resolution for your monitor

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Status: DRAFT
armbian/armbian-2k_resolution.md
Jan 08, 2019
Armbian

tl;dr

this was all in vain since the Orange Pi Plus 2 i was trying to configure didn’t support outputting 2K resolution.. But the method of how to add custom resolution is still valid.

# create mode
xrandr --newmode "2560x1440_60.00"  312.25  2560 2752 3024 3488  1440 1443 1448 1493 -Hsync +Vsync

# add mode
xrandr --addmode default 2560x1440_60.00

# set mode for current display
xrandr --output default --mode 2560x1440_60.00

Get a Modeline using cvt or gtf

cvt calculates VESA CVT mode lines

gtf 2560 1440 60 -x

# 2560x1440 @ 60.00 Hz (GTF) hsync: 89.40 kHz; pclk: 311.83 MHz
Modeline "2560x1440_60.00"  311.83  2560 2744 3024 3488  1440 1441 1444 1490  -HSync +Vsync

gtf calculates VESA GTF mode lines

cvt 2560 1440 60

# 2560x1440 59.96 Hz (CVT 3.69M9) hsync: 89.52 kHz; pclk: 312.25 MHz
Modeline "2560x1440_60.00"  312.25  2560 2752 3024 3488  1440 1443 1448 1493 -hsync +vsync

CVT is a newer (i.e., less ancient) standard. For a LCD panel it shouldn’t matter. The timings are significant only for CRT displays; and even for CRT displays the two sets of parameters should produce just about the same picture.

Create, add and enable a custom resolution mode with xrandr

xrandr is a utility that is used to set the screen size, orientation and display outputs etc.

The --gamma (--gamma <r>:<g>:<b>) value was added to --output because it kept giving the error:

xrandr: Failed to get size of gamma for output default

The value for gamma was found using xgamma

# xgamma
-> Red  1.000, Green  1.000, Blue  1.000

Forces to use a 1024x768 mode on an output called VGA:

xrandr --newmode "1024x768" 63.50  1024 1072 1176 1328  768  771
775 798 -hsync +vsync
xrandr --addmode VGA 1024x768
xrandr --output VGA --mode 1024x768

Add HD-Ready resolution (1280 x 720 - 720p)

xrandr --newmode "1280x720_60"   74.50  1280 1344 1472 1664  720 723 728 748 -hsync +vsync

xrandr --addmode default 1280x720_60

xrandr --output default --mode 1280x720_60 --gamma 1.000:1.000:1.000

On Armbian, if you are getting errors relaed to output, remember that there is only one HDMI port on the Orange Pi plus and the output is called default.

xrandr --fb 1280x720
xrandr: Failed to get size of gamma for output default
xrandr: specified screen 1280x720 not large enough for output default (1920x1080+0+0)

Troubleshooting

  • Reducing the frequency from 60Hz might work. Try 40Hz or 33Hz
  • Find all monitors with xrandr --listmonitors
  • Find current resolution details with xrandr -q

Following are thoughts when i was getting overscan on my TV.. it had nothing to do with the confgurations though, fixed in the end by chnaging TV settings for picture

  • Somewhere along the way i added a monitor profile for Asus 24” VX24AH in /etc/X11/xorg.conf.d and that seems to have messed up the dimensions Nope.
  • I’ll probably have to add a new monitor profile for the Sony Bravia 32” (KLV-32BX350) that i intend on using.. Nope. The issue was with TV’s settings..