Use STEAMVR plug-in to do VR camera, create a sphere, set the appropriate size, placed in the same position as the camera, the video is played on the inner wall of the ball, from the inside of the ball to see the inner wall of the ball.
Drag a panorama to the ball, Sharder with the http://blog.csdn.net/wuyt2008/article/details/54313474 in this link (provided by the great God).
Add the Videoplayer component, add the video you want to play in the vedeoclip below, Rendermode set to Materialoverride.
Use the play (), Stop () and other methods to control.
To display only the Panorama picture, set the Videoplayer component's enabled to False to show only the panorama that started on the drag.
The change of Panorama picture
Renderer.sharedMaterial.mainTexture = thetexture;
The method.
VR Panorama and Panorama video settings in Unity2017