When I use PdfConverter -the images of all pages of a PPT file flip 90 degrees.why?

when I use PdfConverter ,the images of all pages of a PPT file flip 90 degrees.
But not all PPT files.why?
How can I control the image not to flip 90°?//

My code just like this:
PdfConverter objConverter = new PdfConverter();
objConverter.BindPdf("input.pdf");
objConverter.DoConvert();
while (objConverter.HasNextImage())
objConverter.GetNextImage(DateTime.Now.Ticks.ToString() + ".jpg",
System.Drawing.Imaging.ImageFormat.Jpeg);
objConverter.Close();

I use the latest version.

Oh,not flip, rotate is what I mean

Hi John,


Please share the source presentation with us for necessary investigation on our end. Please also share which version of Aspose.Slide you are using along with generated PDF for further investigation on our end.

Many Thanks,