Doesn't work as intended with MediaInfo.NET

[iG8R]

Hi.
The title speaks for itself.

WinSyncScroll-Video_2025-11-13_22-01-32.mp4

https://github.com/stax76/MediaInfo.NET

[magicxor]

Hi @iG8R

1. What version of Windows are you using?
2. Are you logging in directly or via RDP?
3. Have you tried turning on "scroll inactive windows"?
4. Have you tried Legacy mode?

[iG8R]

Hi, @magicxor

1. Microsoft Windows [Version 10.0.19045.2673]
2. Directly
3. This option is turned on by default.
4. Yes, in legacy mode it doesn't work at all.

[iG8R]

It feels like WSS doesn't "pass" all scroll parameters to the to window.
Is there any debug mode to see what is happening?

[iG8R]

Right now I checked the operation of WSS with all other windows (VScode, VS2012, Notepad++, Firefox, Chrome, Edge), it turned out that all of them have the same behavior as in the screencast in the first message.

[magicxor]

It feels like WSS doesn't "pass" all scroll parameters to the to window. Is there any debug mode to see what is happening?

in nlog.config you may check that minlevel = "Trace"

<logger ruleName="AllToFile" name="*" minlevel="Trace" writeTo="logfile">
    <filters defaultAction="Log">
        <when condition="starts-with(logger,'System.') and level &lt; LogLevel.Warn" action="Ignore" />
        <when condition="starts-with(logger,'Microsoft.') and level &lt; LogLevel.Warn" action="Ignore" />
    </filters>
</logger>

then you may check \logs\Log.current.txt

Also, the issue may be related to coordinate conversion, scaling, or the number of displays. How many displays do you have in your system?

[iG8R]

Also, the issue may be related to coordinate conversion, scaling, or the number of displays. How many displays do you have in your system?

2 monitors, the main one, on which I tried to use WSS, is 4K with 150% scaling, and the secondary one is FullHD with 100% scaling.

[iG8R]

Log.current.zip

[magicxor]

2 monitors, the main one, on which I tried to use WSS, is 4K with 150% scaling, and the secondary one is FullHD with 100% scaling.

Thank you for providing the log file. I've reviewed it, but there are no obvious issues.

To help us isolate the problem, could you please try running a test with only one monitor connected?

[iG8R]

I made 2 versions:

1. "soft" - I "disconnected" the second monitor via Win+P and selecting PC screen only.
2. "hard" - I physically disconnected the second monitor.

Log.current.zip

[magicxor]

Thanks. Did the scrolling work on any of these attempts?

[iG8R]

Unfortunately, no. Still the same as in the first post.

[magicxor]

I have another theory we could investigate. It's possible the issue is related to UIPI.

If you have a moment, could you please try running WSS as an Administrator?

It would be very helpful if you could test this in both configurations:

• Running as Administrator with Legacy Mode disabled.
• Running as Administrator with Legacy Mode enabled.

Please let me know if either of those combinations makes any difference. Thanks!

[iG8R]

Unfortunately, the results are still the same:

1. Running as Administrator with Legacy Mode disabled - still the "to" window is jerking and stalling like in the video earlier.
2. Running as Administrator with Legacy Mode enabled - the "to" window doesn't react at all.

[iG8R]

I still found an application that works with WSS without problems - just plain MediaInfo. (https://mediaarea.net/en/MediaInfo)
All other apps I mentioned earlier still don't work properly.

WinSyncScroll-Video_2025-11-14_16-43-40.mp4

[magicxor]

Currently, the application sends all three inputs (Move to Target, Scroll, Move back to Source) as a single batch. My hypothesis is that Windows might be processing the final "Move back to Source" command before the target window has fully registered the "Scroll" command at the target coordinates.

I've created an experimental build that changes this logic. Instead of sending one large array of commands, it now sends three separate, sequential SendInput calls:

1. Move cursor to target
2. Send scroll command
3. Move cursor back to source

The hope is that this forces Windows to process each step in the correct order.

diff --git a/WinSyncScroll/ViewModels/MainViewModel.cs b/WinSyncScroll/ViewModels/MainViewModel.cs
index d424946..61b3414 100644
--- a/WinSyncScroll/ViewModels/MainViewModel.cs
+++ b/WinSyncScroll/ViewModels/MainViewModel.cs
@@ -323,14 +323,27 @@ public sealed partial class MainViewModel : IDisposable
                     var inputScrollTarget = CreateScrollInput(buffer.MouseMessageId, targetAbsoluteX, targetAbsoluteY, delta);
                     var inputMoveToSource = CreateMoveInput(sourceAbsoluteX, sourceAbsoluteY);
 
-                    var inputs = new[] { inputMoveToTarget, inputScrollTarget, inputMoveToSource };
-
                     _mouseHook.SetPreventRealScrollEvents();
 
                     if (!_options.Value.IsLegacyModeEnabled)
                     {
-                        LogSendInput(inputs);
-                        PInvoke.SendInput(inputs.AsSpan(), SizeOfInput);
+                        // Send events sequentially to ensure proper timing and processing order
+                        // This prevents the cursor from moving back to source before the scroll event is processed
+                        
+                        // Step 1: Move cursor to target window
+                        var moveToTargetArray = new[] { inputMoveToTarget };
+                        LogSendInput(moveToTargetArray);
+                        PInvoke.SendInput(moveToTargetArray.AsSpan(), SizeOfInput);
+                        
+                        // Step 2: Send scroll event at target location
+                        var scrollArray = new[] { inputScrollTarget };
+                        LogSendInput(scrollArray);
+                        PInvoke.SendInput(scrollArray.AsSpan(), SizeOfInput);
+                        
+                        // Step 3: Move cursor back to source window
+                        var moveToSourceArray = new[] { inputMoveToSource };
+                        LogSendInput(moveToSourceArray);
+                        PInvoke.SendInput(moveToSourceArray.AsSpan(), SizeOfInput);
                     }
                     else
                     {

Would you be willing to test this experimental build?

1.4.0-rc.1-experimental.fix1.zip