How to do it...

To ensure a movie is prepared before it's played by subscribing to a prepareCompleted event, do the following:

1. Add a UI RawImage to the scene by going to GameObject | UI | Raw Image.
2. Create a new, empty GameObject named video-object.

3. Create a C# script class named PrepareCompleted and attach an instance of the script as a component to the video-object GameObject:

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Video;
 
public class PrepareCompleted: MonoBehaviour {
  public RawImage image;
  public VideoClip videoClip;
 
  private VideoPlayer videoPlayer;
  private AudioSource audioSource;
 
  void Start() {
     SetupVideoAudioPlayers();
     videoPlayer.prepareCompleted += PlayVideoWhenPrepared;
     videoPlayer.Prepare();
     Debug.Log("A - PREPARING");
  }
 
  private void SetupVideoAudioPlayers() {
     videoPlayer = gameObject.AddComponent<VideoPlayer>();
     audioSource = gameObject.AddComponent...