If you put a fisheye lens on each of the S6's cameras can you make a budget Gear 360?

The Galaxy S6/S6Edge/S6Edge+/Note5/S7/S7Edge all have two cameras that can record at the same time if you install the Dual Camera plugin from Galaxy Apps. They can record at a maximum of 1080p each and take pictures at 16MP+5MP. If you bought two universal fisheye lenses for smartphones (they usually come in kits if three fisheye, wide angel and macro) the combination of the two lenses would make a full sphere. The only problem is how would they be stitched together I don't know any software that can do that. On a side note why are all VR videos encoded in a rectangle? That means like a globe into a map the original video needs to be flatened out which means the top and bottom pixels would be very stretched and the middle pixels would be very squished. Wouldn't it make more sense to create a new file format where every pixel corresponds to a location on a sphere and not on rectangle.