360 Video UV mapping Problem

Hi, would like to ask from the above frame of an video, how do i map this 360 video to a cube seamlessly, currently using a T-Shaped uv map and i cant get the proper ratio of how each faces of the cube to fit seamlessly.
Tried with a Sphere but it does not look realistic enough for a vr project.

Would anyone be able to give some recommendations on the proper way of doing so? Thx in Adv. ^^