A source with 1920x1080 and par 16:15 has a natural size of 2048x1080. The current code is incorrectly setting the natural width as height resulting in 1920x2048. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8693>
The automatic scaling done by framepositioner does not account for the par of the video source. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2423>