In the 4.1.25 VidyoClient release, High DPI support was introduced. This may cause a change in the scaling of the rendered video in your .NET application, as the dimensions of the video panel is measured in points rather than pixels. Therefore, you should use the new VidyoConnectorShowViewAtPoints API, rather than VidyoConnectorShowViewAt. The differences are explained below:
VidyoConnectorShowViewAt uses pixels for its arguments. Consequentially, passing in the height / width of a WindowsFormPanel (who's height and width is in points) will cause the video view to appear as a different size than it should be.
VidyoConnectorShowViewAtPoints, on the other hand, accepts points for all of it's arguments. This means that in the case of a WPF application using a WindowsFormPanel, that passing in the height and width of the panel will result in the panel's view size appearing correctly.