Put spherical 180° texture to sphere

Hi
I will create a 3d vr video player. I use 2 spheres (left and right eye) and SteamVR. I added a shader to the spheres (cull mode front) and the cameras are in the spheres.

It's working good, the 180° 3d video is playing, but a border appears on top and bottom. The video is spherical 180° and I have no idea, how I can fix this.

Can you please help me?

 

Perhaps, my explaination is a bit complicated.

In short: I wish to use a sphere mesh as a skybox, but I have to set tiling and offset values, because the video is sbs (side-by-side) and a regular skybox shader can't handle this. I could not figure out, how I can create a skybox shader in amplify shader. How can I display the spheric texture (render texture) to a sphere mesh, without the perspectific issues like in the image?

 

I found the solution: Use an octahedron sphere, not a regular.