macgomes
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How can i fix settings of over-scan on PI4

Tue Sep 03, 2019 10:12 am

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Last edited by macgomes on Tue Sep 03, 2019 8:25 pm, edited 2 times in total.

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FTrevorGowen
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Re: How can i fix settings of over-scan on PI4

Tue Sep 03, 2019 3:38 pm

macgomes wrote: Hello everyone,,,
I have a Philips LCD TV that I am using the PI4 on, and it keeps on over-scanning. I tried many outdated solutions such as the config.txt, and PI4 screen configuration, But nothing is working. I know you are smart, so can you please help me.
I am new to the PI community, so please be more clear with your solutions,
thank you!
Currently** (unless things have changed very recently) overscan/underscan settings in config.txt are not (cannot yet) be "passed through" to the DRM VC4 V3D driver so the quickest way to enable such is to disable that driver - see this section of config.txtr:

Code: Select all

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
# dtoverlay=vc4-fkms-v3d
max_framebuffers=2
Trev.
** AIUI it's work in progress w.r.t. how Buster handles edids etc. and passes settings to DRM (eventually) and there are other threads here that discuss the issue and progress so far (almost there ...).
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

6by9
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Re: How can i fix settings of over-scan on PI4

Tue Sep 03, 2019 4:46 pm

The kernel can now do it, but the firmware isn't passing it through automatically.

Edit /boot/cmdline.txt.
Add to the end (do NOT add any line breaks)

Code: Select all

video=HDMI-A-1:[email protected],margin_left=48,margin_right=48,margin_top=64,margin_bottom=64
with the resolution modified to match whatever it is that your monitor wants, and the margins set appropriately.

NB The kernel chooses to scale all the planes, rather than resize the frame buffer or modes to reduce the size by the amount of overscan applied. Things will be a little blurrier than ideal.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

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FTrevorGowen
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Re: How can i fix settings of over-scan on PI4

Tue Sep 03, 2019 8:57 pm

6by9 wrote:
Tue Sep 03, 2019 4:46 pm
The kernel can now do it, but the firmware isn't passing it through automatically.

Edit /boot/cmdline.txt.
Add to the end (do NOT add any line breaks)

Code: Select all

video=HDMI-A-1:[email protected],margin_left=48,margin_right=48,margin_top=64,margin_bottom=64
with the resolution modified to match whatever it is that your monitor wants, and the margins set appropriately.

NB The kernel chooses to scale all the planes, rather than resize the frame buffer or modes to reduce the size by the amount of overscan applied. Things will be a little blurrier than ideal.
Thanks for the update - time to compare both methods with my "tricky T.V." now I guess (and post some screenshots/photo's in my webpages ...?)
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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FTrevorGowen
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Re: How can i fix settings of over-scan on PI4

Sat Sep 07, 2019 1:14 pm

FTrevorGowen wrote:
Tue Sep 03, 2019 8:57 pm
... time to compare both methods with my "tricky T.V." now I guess (and post some screenshots/photo's in my webpages ...?)
Trev.
FWIW, here they are: http://www.cpmspectrepi.uk/raspberry_pi ... erP4B.html
NB: The "non-FKMS" overscan offsets are applied to the default overscan settings for CEA modes** - hence the negative numbers.
Trev.
** See the docs. here (Generic display options section): https://www.raspberrypi.org/documentati ... t/video.md
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

sublethalhippo
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Re: How can i fix settings of over-scan on PI4

Wed Sep 18, 2019 9:36 pm

Just made an account to point out that none of these solutions worked for me. I'm about ready to light it on fire. Rpi 2, 3, 3b+ never had any issues not being able to fix the underscan but it is so bad on the Rpi 4 that I can barely see the taskbar. All I wanted was more ram for having more than 1 tab open in the browser, but apparently that was too much to ask while also getting it to fit the TV. I will be downgrading back to a 3b+ now.

/boot/config.txt changes don't work
/boot/cmdline.txt changes don't work
using raspi-config and going to advanced settings to fix overscan doesn't work.
I didn't even know, until I booted into HDMI safe mode, that there's an icon apparently telling me there's some battery discharge issue next to the clock?

Honestly I'm just really disappointed in this product. I really wish I would've played with it more the week I got it so I could've returned it. As of right now it is not usable and not this post nor any others on Google have solved the problem.

No my TV does not have options to correct it.
No it is not old. It is an insignia TV from Best Buy, less than 2 years old.

6by9
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Re: How can i fix settings of over-scan on PI4

Thu Sep 19, 2019 6:31 am

Overscan settings should now all be configured automatically by the firmware in the same way as before.

I'm not sure when the last drop into apt was - there were talks of updating, earlier this week, but I'm not sure if it happened. Its certainly I. The rpi-update repos.

And please watch the language - this is a family friendly forum, so profanities are not welcome.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
I'm not interested in doing contracts for bespoke functionality - please don't ask.

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