I've connected a HDTV with HDMI on my Radeon 4670, using the open source ati driver. However there is "overscan" which cuts off a bit of each edge of the screen, about the size of the gnome-panel. How can I fix this so it displays the full resolution?
The issue was with the TV, not Ubuntu.
- Samsung TV - go to Menu / Picture / Picture Options / Size / Screen Fit (instead of 16:9).
- LG TV - go to Settings / Picture / Aspect Ratio / Just Scan (instead of 16:9)
- Sony TV - hit Home button, go to Settings / Screen / Display Area / Full Pixel
- Sharp TV - hit View Mode button, select "Dot by Dot" or "Full screen"
As the above comments are saying, the problem is most likely due to the TV and not the driver.
However, if you have a Sharp Aquos TV, "Dot by Dot" mode might not be available in the menu as Pakman mentioned; I couldn't find an option for enabling "Dot by Dot" mode anywhere.
Instead, I solved the problem by discovering that my remote has a dedicated "Wide Mode" button for this setting, which looks kind of like this:
|<>|. Press it to toggle from Stretch to Dot by Dot mode.
Fixing HDMI overscan on a Samsung TV
I connect my laptop to the HDMI input of my Samsung TV. Due to overscan, The TV annoyingly puts part of the image outside the visible screen, even though the resolution is correctly set to 1080p. Here is a solution:
- Press Source on your remote
- Move down to your HDMI source and press Tools
- Select Edit name Scroll down to PC and select that one
Your screen goes blank for a second – and mission accomplished: the overscan is disabled.
I Have struggled with this problem for longer than I care to say! This may help if you have a NVidia graphics card, and Ubuntu 14.04.
Go to the Ubuntu software center, search for NVidia drivers and download "Nvidia X Server Settings".
Once downloaded, click on the Nvidia icon, and select x server display configuration.
Once there, simply slide the underscan slider until the desired size is achieved.
New TVs are set to allow overscan, so the driver will often do that very overscan that is available when set to a desktop resolution.
So, the driver for the video card - might - have an overscan setting to resolve this if lucky, or as Hew found out you might be able to set the TV to display the incoming signal without overscan.
Try the video display driver first, then if no luck, try your TV settings. It is best to correct in the driver setting first, instead of setting a fixed display.
I was attempting to solve this problem this afternoon. A Sharp TV would not let me change selection from "stretch" to "dot by dot". It gave me a message:
No input selection available
A solution that served my purposes (not losing part of the screen) was to switch to the lower resolution of 1360 x 768 instead of 1920 x 1080.
Since I just wanted to run emacs on the TV, losing some resolution was not a big deal.
This is kindof a dumb workaround, but since no-one else seems to mention it, I figured this answer would contribute.