How to get the media format/extension of MediaPicker?

[CodingOctocat]

I need to write photo or video streams to a file, what is their format? How should I determine the extension?

photo = await MediaPicker.CapturePhotoAsync(options);
video = await MediaPicker.CaptureVideoAsync(options);

[CodingOctocat]

FileResult.ContentType: Gets or sets the file's content type as a MIME type (e.g.: image/png).