I have an old .Net application that I wrote years ago that includes a video preview window. This uses a 3rd party library called DirectShowLib-2005.dll. My code is based on some example code I found online that I converted from c# to Vb.net. Basically it just sets up a simple capture graph and uses a SampleGrabber to link the video stream to a PictureBox control on a form.
This has been working fine with various users around the world, but recently we have had several new users who have reported that no image is displayed. At first we thought it might be an issue with camera drivers, but I can see that video data is coming through in the memory buffer.
It is difficult for me to debug as none of the machines I have access to show the problem. I do have one laptop that shows a slightly different problem. It does show an image but only part of the image is shown. Looks like it has been incorrectly centred. I discovered that changing the Text scaling in Windows display settings to 100% fixes this. This does not fix it for other users reporting the problem though, and they are seeing a grey background rather than a black background that I see.
My boss has the problem on his laptop PC. We have found that setting the Reduced Colour Mode in Compatibility Settings to 8-bit in the application shortcut properties fixes the problem for him.
I am trying to extract the essential part of the code into a separate test app so I can hopefully debug it a bit better, but I wondered if this is a known problem with modern PCs, or perhaps an issue with certain graphics cards or display drivers?
Thanks
Phil