Topic: Windows Video Conversion Software for 120 fps, 240 fps Videos

Does anybody know of a Windows video conversion or editing program that would allow rotation of a video file in 90 degree increments and still retain 120 fps or 240 fps video resolution.  Most software I have tried converts the video to 30 or 60 fps.  I think these programs drop video frames to allow the video to play at the lower frame rates but maintain the intended playing speed.  I am using 120 and 240 fps video from a Gopro and iPhone and I need the images rotated by 90 degrees but I don't want to lose the higher frame rates.