Want to adjust a Quad / Plane to the size of what the camera renders for playing a video ? heres how you doit

gistfile1.txt

//Adjust the size of the transform to ocuppy the whole size of the camera being rendered
	
void Start () {

    float distance = Vector3.Distance(Camera.main.transform.position, transform.position);
    float sizeHeight = Mathf.Tan(Mathf.Deg2Rad * Camera.main.fieldOfView/2) * distance;

    float radAngle = Camera.main.fieldOfView * Mathf.Deg2Rad;
    float radHFOV = 2 * Mathf.Atan(Mathf.Tan(radAngle / 2) * Camera.main.aspect);
    float hFOV = Mathf.Rad2Deg * radHFOV;

    float sizeWidth = Mathf.Tan(Mathf.Deg2Rad * hFOV/2) * distance;
    transform.localScale = new Vector3(sizeWidth*2, sizeHeight*2, 10);
}