iPhone makes videos for me by date using pictures and videos that

iPhone make videos from pictures and videos that I have for a certain day. I can edit add or delete pictures and choose the music and length of the videos Everything is great. But when I save the video it clips off the top and bottom of the video. Is there a way to save it in the original form that it shows me before I save it? Or do I need to use a different app to create video and picture compilations that show the full view of what is there before it is saved. This is frustrating.