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Output Resolution

Posted: Thu Jan 10, 2019 8:37 am
by vsavu
How can we change the output resolution in raspbian?

xrandr only shows the current resolution (1080p when connected to a 4k monitor).
config.txt on the first partition does not set the resolution (can it?)

Re: Output Resolution

Posted: Thu Jan 10, 2019 10:04 am
by MattMunro
Hi,
This currently needs to be changed in "/etc/modprob.d/stmfb.conf", there's currently a patch in the works to allow config.txt to change it however.
Thanks,
Matt
edit: changed address to be correct.

Re: Output Resolution

Posted: Thu Jan 10, 2019 12:52 pm
by vsavu
Did you mean "/etc/modprob.d/stmfb.conf"?

Re: Output Resolution

Posted: Thu Jan 10, 2019 2:17 pm
by MattMunro
Hi,
Yes, sorry.
-Matt

Re: Output Resolution

Posted: Thu Feb 07, 2019 5:32 pm
by irisg_guy
Hi Guys,
What exactly needs to be changes in this file to get 4K

"/etc/modprob.d/stmfb.conf"

Re: Output Resolution

Posted: Thu Feb 07, 2019 5:49 pm
by nick.beck
Hi,

I don't have a board to hand to check this exactly, but in /etc/modprobe.d/stmfb change the following line:

options stmfb display0=1280x720-32@50:64m:128m:ntsc:yuv:yuv \

to the following for 4K 50Hz output when you restart the board:

options stmfb display0=3840x2160-32@50:64m:128m:ntsc:yuv:yuv \

Re: Output Resolution

Posted: Fri Feb 08, 2019 6:26 am
by irisg_guy
Thanks Nick... I will test it later.

Re: Output Resolution

Posted: Fri Feb 08, 2019 10:05 am
by irisg_guy
I changed that line - rebooted the board but the output is still 1080p... See file below

Any ideas?


# Generated by sdk2-build-master/modprobe.d/stmfb.conf template

# Tutorial:
# display0=1280x720-32@50:24320k:128m:ntsc:yuv:yuv is remaining the main display
# display0 is defined to set main output:
# Example of usage:
# display0=1280x720-32@50:24320k:128m:ntsc:yuv:yuv
# If board is supporting AUX display we should set for example:
# display1=720x576-16@50i:3m:0:pal:cvbs is remaining for AUX display when AUX_EN=1 in the automatic generation
# display1=720x576-16@50i:3m:0:pal:cvbs
# Depending on standards used you need to select
# For EU standard: @50 hz, ntsc mode and height 480
# For USA standard: @59 hz, pal and height 576
# /usr/bin/stfbset -f /dev/fb1 -a 0 -M 0x10101060; is defined to configure AUX output setting for transparency and Mixer background
# Example of usage:
# /usr/bin/stfbset -f /dev/fb1 -a 0 -M 0x10101060;

alias fb0 stmfb

options stmfb display0=3840x2160-32@50:64m:128m:ntsc:yuv:yuv \
display1=720x576-16@50i:3m:0:pal:cvbs

###########
# LOADING #
###########

# Load stmfb
install stmfb \
/sbin/modprobe coredisplay; \
/sbin/modprobe --ignore-install stmfb; \
/usr/bin/stfbset -a 0 -M 0x10101060; \
/usr/bin/stfbset -f /dev/fb1 -a 0 -M 0x10101060;

#############
# UNLOADING #
#############

# Unload stmfb
remove stmfb \
/sbin/modprobe -r --ignore-remove stmfb; \
/sbin/modprobe -r coredisplay

Re: Output Resolution

Posted: Fri Feb 08, 2019 1:30 pm
by MattMunro
Hi,
I'm currently looking it this, would it be possible to get the output from you running "fbset" on the board? This should output its current settings.
If the monitor doesn't support 4k it shouldn't display anything rather than displaying 1080, but is the monitor 4k capable?
I'll update you if I find anything out.
Thanks,
Matt

Re: Output Resolution

Posted: Fri Feb 08, 2019 1:57 pm
by irisg_guy
Hi Matt,
Thanks for your help.... It is a 4k monitor.

I have tested the directly and it works fine.

Regards,
Louis