Hi everyone

I have an old 32" Sony Bravia KDL-32S2530 from about 2007. It's a 1080i/720p set with a panel size quoted as 1366x768 and I've always had issues connecting PCs to the HDMI inputs. The manual recommends connecting computers via VGA but we're almost into 2017 I don't fancy doing that anymore.

The old Windows XP Zotac Ion HTPC (connected by VGA) is finally getting the boot and is being replaced by a Gigabyte Brix, running Xubuntu. I'm a Linux server guy so all this Xorg/desktop fudging is new to me - Xubuntu on laptops just works and I can get on with some work

It boots fine although the BIOS menu is a bit scrambled and it whinges about "no suitable video mode found... booting in blind mode" but eventually XFCE/Unity appears, in perfectly crisp detail.

The issue I have is that the desktop is positioned about 20px off the top left of the visible area of the panel.
All the advice I've read over the past few days has suggested disabling "overscan" on the TV or adjusting the picture scale/alignment in the TV settings. Unfortunately this TV does not have those functions.

I have the desktop resolution set to 1280x720 because the text is much more readable than in 1080i.

The full output from xrandr --verbose can be seen here... http://pastebin.com/eY3NyAhr

So far I have managed to get the top-left of the screen aligned perfectly using...
But I've obviously lost the shifted pixels off the right and bottom sides of the display. What's the best way to solve this?

I have tried using the xrandr --fb option and subtracting (2*30)+(2*18) from 1280x720 and rounding to a multiple of +-8...
And I just get a black border to the right and bottom so my calculations are wrong for the --fb option. But it feels like I'm close.
I'm not sure where the 1344x756 comes from.

Anyone got any suggestions?

For years I have had a Raspberry Pi + openelec running perfectly on this HDMI input, Linux-based, so I know it can work. But I'm sure Openelec/Kodi is using something very different to draw to the screen. In Openelec I was able to manually adjust the screen offset and save the settings to the Pi's config.txt. I booted up Raspbian to check the modeline/xrandr output but it's completely different... http://pastebin.com/SdM0aQvP

Thanks, B

I have had the same problem with a damnable Polaroid HDTV that similarly has no option to eliminate overscan on the HDMI input (not when it detects the input is either 1080p or 720p, but it does allow dot-for-dot modes for other resolutions, damn it!).

I didn't have luck getting the transform stuff to do what I wanted. If I recall, I got about as far as you've already gotten. I gave up on it.

Instead, my solution was to leave the xrandr HDMI output the default, and use the XFCE4 settings to tell it to position windows within the visible box. This means there's still a border of invisible pixels all around the screen, but windows are not positioned in that area. It's a bit annoying that the mouse pointer can freely wander off into the invisible borders, but it's not too bad.

Go to Settings -> Workspaces -> Margins. Huh? Workspaces? Why is this under the "Workspaces" setting rather than Window Manager or Window Manager Tweaks? Heck if I know. Whatever. That's where the Margins settings is. Go there, and fiddle with it, and enjoy.

But before messing with the Margins, first drag your Panel(s) into the visible area. Open up the Panel settings, if necessary, to uncheck "Lock Panel". Then fish for the drag bars at the corners of the screen. Once you've dragged the panel(s) just into the visible area, then you can adjust the Margins with a maximized window to get everything to just barely fit.

Check this out: https://www.mythtv.org/wiki/Working_with_Modelines

I had read through that page so many times and dismissed it as far too difficult to get a custom mode working. But bingo!!!

With the help of a script to sleep 10 and reset to a preferred mode after each attempt, and checking into git as I got better results... I now have a display that fits within the screen. I am amazed and never thought it would be possible!

The key was "Getting rid of overscan and centering the image" and this in the previous paragraph...
Once I got the left side on I managed to bring the top down by moving and scaling. A black bar appeared at the bottom for a while but managed to tweak gradually to get it into position.

It ended up being 1218x685.
Thank you so much Emerson!

The only issue I have is that the HDMI output from the Brix goes into my surround sound receiver (Yamaha RX-V667) as a passthrough. All is good until I turn on the receiver and the picture is blanked with the receiver reporting 576p. Turning off the receiver and the picture does not return until I reset the Brix.

This happens even straight from boot, just using a preferred mode through xrandr, without any of my adjustments. It seems there is something about Brix/Xubuntu HDMI output signal that the receiver fundamentally doesn't like.

Are there any other HDMI settings I need to tweak anywhere?
Keeping the signal open or performing a handshake on link change etc?

EDIT: Is it worth trying with the output of...
which I believe would give me a validated/compliant modeline?

I was hoping the Brix could replace my HTPC (well, Skype/web kiosk) and my rPi+Openelec for entertainment so I'd quite like to get the receiver passthrough working if I can.

Thank you for all your help so far - I never thought I would even get here!

Cheers, B

This is the area where open source OS are quite lacking and effort is not worth spending. I simply reboot to Windows.

You can try xrandr --auto to refresh outputs.

I have no idea if this will help (or if it's even relevant). I had a 20-inch 1680x1050 monitor that would only display at 800x600 and 1024x768. Adding an xorg.conf file with a display size specified in the monitor section allowed me to get the full native resolution of the monitor. The specified display size was actually larger than the dimensions of the monitor, but the were in a 16:10 ratio. However, that was with a VGA connection.