private async Task SetPreviewRotationAsync()
{
// Populate orientation variables with the current state
_displayOrientation = _displayInformation.CurrentOrientation;
// Calculate which way and how far to rotate the preview
int rotationDegrees = RotationHelper.ConvertDisplayOrientationToDegrees(_displayOrientation);
// The rotation direction needs to be inverted if the preview is being mirrored
if (_mirroringPreview)
{
rotationDegrees = (360 - rotationDegrees) % 360;
}
// Add rotation metadata to the preview stream to make sure the aspect ratio / dimensions match when rendering and getting preview frames
var props = _mediaCapture.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview);
props.Properties.Add(new Guid("C380465D-2271-428C-9B83-ECEA3B4A85C1"), rotationDegrees);
await _mediaCapture.SetEncodingPropertiesAsync(MediaStreamType.VideoPreview, props, null);
}