Monitor assignment changes when shutting TV off

[paul1965]

I have a new slideshow setup that I'm struggling to get working correctly. I used to have 2 SFF PC's running 2 different slideshows: one a Photowall, the other PC ran 3 standard slideshows using 3 different directories. The Photowall slideshow was triggered using an AutoHotKey script, the standard ones were triggered by a Powershell script. Both PC's sent their signals into an HDMI switch with PiP functionality, with Photowall displaying on monitor 1, the others on 2, 3 and 4 respectively. Things were working great until I decided to combine all of the slideshows onto a single PC.

Since my GPU is limited to 3 monitors, I connected a USB DP to HDMI adapter creating 2 monitor outputs, then use 2 OE DP connectors on the PC. All outputs go into the existing HDMI switch as before. Using the same scripts as before, things work great until I shut the TV off, then later turn it back on. Each time that happens, the monitor assignment in GPS gets changed, and the slideshows get moved to a different input. I never see the Windows (11) assigned monitor number get changed, only the GPS ones. After reading a somewhat similar post here about slideshow issues when turning the monitor off, I upgraded to the DX version, but the issue still persists.

Other than going back to a 2 PC setup, are there any suggestions on preventing these slideshow issues?

[gpb]

Hello,
Unfortunately the change of monitor order is caused by the windows api used by gPhotoShow to get the monitor list. I don't know the reason but in some cases the order changes.
With the current version the only solution is to use a custom layout. In the multiple monitors page instead of setting the monitor index set a custom layout and enter the coordinates of that monitor (position and size). gPhotoShow fills the list with all monitor, just remove the one you don't use for that slideshow.

In a next update I will add the possibility to sort monitors based on their position, in this way unless monitor position is changed they always keep the same index.

[paul1965]

I looked at that a bit, and see that even the index values appear to change. One time I see four values, 0-3, then it's 1-4, then check again for the standard slideshows I see 1-3, for the Photowall I see just 1.

[gpb]

I don't understand the way you configured gPhotoShow. How did you configure the multi monitors page ?
If you set the slideshow to display only on a specific monitor index by switching to a custom layout should fix you issue. When using a custom layout gPhotoShow will create its windows at the specified position regardless the monitor index, only position and size is important.

[paul1965]

I don't understand the way you configured gPhotoShow. How did you configure the multi monitors page ?
If you set the slideshow to display only on a specific monitor index by switching to a custom layout should fix you issue. When using a custom layout gPhotoShow will create its windows at the specified position regardless the monitor index, only position and size is important.

Right now the slideshows are set with "only monitor XX", then the Powershell script runs with the corresponding switch for the same monitor. I'll go back and check the custom layout settings again, as seeing the different index data is throwing me off. How do I know which one to use for each slideshow? Does the index number indicate the monitor number? Or something else?

[paul1965]

I edited the 3 slideshows and set them for custom layout. While the preview of each one worked, that setup broke my Powershell script, I assume because it relied on the monitor switch. Can multiple instances of the slideshows still be triggered with the script when using custom layout?

[gpb]

To run multiple instances of gPhotoShow run regedit.exe, then go to this key:
HKEY_CURRENT_USER\Software\GPGSoftware\gPhotoShow\Settings

Create a new DWORD value:
NoSingleInstCheck = 1

If you run gPhotoShow from a command line you have another option, use the parameters /w

/w:x,y,width,height,flags
With this command it is possible to position the gPhotoShow window at a specified position the windows virtual screen (the union of all active monitors)
x,y: Window position in pixel
width,height: Window size in pixel
flags: Settings for the gPhotoShow window
0= Default. gPhotoShow window is always on top and always tries to stay there
1= Created on top of other windows but doesn't try to stay there
2= Created as normal window
4= Visible in the windows taskbar
8= Show title bar

[paul1965]

Thanks, I might give that a try. I'm pretty certain now though that it's a hardware issue, and will be trying a different USB video card over the weekend to see if that changes anything.

[paul1965]

To run multiple instances of gPhotoShow run regedit.exe, then go to this key:
HKEY_CURRENT_USER\Software\GPGSoftware\gPhotoShow\Settings

Create a new DWORD value:
NoSingleInstCheck = 1

This was mostly a hardware issue. After I swapped in another EliteDesk that had 3 OE DP connections, then adding my USB video card for the 4th monitor, I no longer had an issue with monitor assignments changing after turning the TV back on. However, I still had an issue after rebooting. Setting the slideshows to use a custom layout has resolved that issue.

Adding the new DWORD to the registry made it very easy to create a new Powershell script to run the 3 slideshows simultaneously, so thanks for the help!