My display is a TV with resolution of 1366x768 @60 Hz. It has HDMI input option as well as PC input option. I prefer HDMI input but I'm not getting the appropriate image of RPI 4B with 4GB with HDMI. I borrowed a monitor and found that display is excellent without me doing any configuration from the RPI 4B. I'm a noob and could not set it correctly on my tv with built in screen configuration tool of RPI 4B. When I set 1366X768 resolution my TV first shows a message 'unsupported' but after about a minute the display comes on the screen which is not the best. I ran tvservice and got the following best score by GREP: HDMI:EDID Best score mode is now DMT (81) 1366x768p @60Hz with pixel clock 85 Mhz (score 5188835). I'm confused about DMT and CEA as I read somewhere that DMT is intended for monitors while mine is a TV. Even if DMT is the right option I need step by step guidance on how to set my TV display to DMT 81. Please help. (I've very little knowledge of linux commands but I'll be able to follow a detailed guidance).
You could try 720p mode as you have a Pi 4:
Full config details are here on the RPF site.
Add the following lines into /boot/config.txt
and restart the computer.
Edit: To use dmt add:
and restart the computer
I did a little research and ran the following commands (without quotes of course) in Terminal.
"/opt/vc/bin/tvservice -m CEA"
"/opt/vc/bin/tvservice -m DMT"
I also ran the following commands:
"/opt/vc/bin/tvservice -d edid.dat"
As I wanted sound through HDMI, I preferred Group CEA and Mode 16 which appears as native. Next I took out the micro sd card and with a text editor uncommented and edited (in my android phone as my Windows PC is out of order) the relevant entry to change it to hdmi_group 1 and hdmi_mode 16 in the config.txt file. The following is the entry I uncommented and edited.
uncomment to force a specific HDMI mode (this will force VGA)
My TV still shows a unsupported message at first but switches to 1920x1080 display after about a minute. I'll welcome further suggestions in this regard!
Here are the outputs I got from Terminal from the first two commands:
pi@raspberrypi:~ $ /opt/vc/bin/tvservice -m CEA
Group CEA has 16 modes:
mode 1: 640x480 @ 60Hz 4:3, clock:25MHz progressive mode 2: 720x480 @ 60Hz 4:3, clock:27MHz progressive mode 3: 720x480 @ 60Hz 16:9, clock:27MHz progressive mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive mode 5: 1920x1080 @ 60Hz 16:9, clock:74MHz interlaced mode 6: 720x480 @ 60Hz 4:3, clock:27MHz x2 interlaced mode 7: 720x480 @ 60Hz 16:9, clock:27MHz x2 interlaced
(native) mode 16: 1920x1080 @ 60Hz 16:9, clock:148MHz progressive
mode 17: 720x576 @ 50Hz 4:3, clock:27MHz progressive mode 18: 720x576 @ 50Hz 16:9, clock:27MHz progressive mode 19: 1280x720 @ 50Hz 16:9, clock:74MHz progressive mode 20: 1920x1080 @ 50Hz 16:9, clock:74MHz interlaced mode 21: 720x576 @ 50Hz 4:3, clock:27MHz x2 interlaced mode 22: 720x576 @ 50Hz 16:9, clock:27MHz x2 interlaced mode 31: 1920x1080 @ 50Hz 16:9, clock:148MHz progressive mode 32: 1920x1080 @ 24Hz 16:9, clock:74MHz progressive
pi@raspberrypi:~ $ /opt/vc/bin/tvservice -m DMT
Group DMT has 7 modes:
(prefer) mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive
mode 8: 800x600 @ 56Hz 4:3, clock:36MHz progressive mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive mode 22: 1280x768 @ 60Hz 15:9, clock:68MHz progressive mode 81: 1366x768 @ 60Hz 16:9, clock:85MHz progressive mode 85: 1280x720 @ 60Hz 16:9, clock:74MHz progressive