c# - 使用 Unity Video Player 连续无缝播放不同的视频

Question

对于这个关于 Unity 的视频播放器组件的问题，有没有人有任何解决方案？

基本上，我有一个半交互式应用程序，可以在发生某些事情时连续播放一系列视频。问题是第一个视频结束后会有 3-5 秒的空隙，因为第二个视频需要时间加载，但这在我的应用程序中看起来不太好。

我需要一种方法来预加载第二个视频(理想)或一种相当简单的方法来隐藏间隙(如顶部的静止帧)。对于后一个想法，我应该提到视频是球形显示的。

using UnityEngine;
using UnityEngine.Video;

public class selectAndPlay_video : MonoBehaviour {

    public VideoPlayer videoPlayer;
    public VideoClip NewClip;
    void OnEnable()
    {
        videoPlayer.loopPointReached += loopPointReached;
    }

    void OnDisable()
    {
        videoPlayer.loopPointReached -= loopPointReached;
    }

   void loopPointReached(VideoPlayer v)

    {
       videoPlayer.clip = NewClip;
       videoPlayer.Play();
     }
}

Answer 1

解决这个问题的关键是VideoPlayer.Prepare()函数，VideoPlayer.time和VideoPlayer.clip.length特性。首先，我确实建议您忘记当前使用事件播放视频的方式。使用来自 this 的示例中的协程问题，因为下面答案中的所有内容都假定您在协程函数中。以下是如何播放不同的视频而无需长时间等待:

1。有要播放的 VideoClip 数组/列表。

2。从 #1 中的 VideoClip 数组创建新的 VideoPlayer 列表。只需使用 #1 中的 VideoClips 设置 VideoPlayer.clip 属性。

3.调用VideoPlayer.Prepare()准备列表中的第一个VideoPlayer然后等待while 循环，直到准备完成或 VideoPlayer.isPrepared 变为 true。

4.调用VideoPlayer.Play()播放您刚刚在#3中准备的视频。

Play different videos back to back seamlessly

这是最重要的部分。

播放视频时，检查正在播放的VideoPlayer的当前时间是否是视频长度的一半。如果播放到一半，则对数组中的下一个视频调用 VideoPlayer.Prepare()，然后等待来自 #4 的视频播放完毕，然后再播放下一个视频。

通过这样做，下一个视频将在当前视频仍在播放时自行开始准备，并且准备过程应该在当前视频播放完毕时完成。然后您可以播放下一个视频，而无需长时间等待它加载。

5。等待来自 #4 的视频在 while 循环中完成播放，直到 VideoPlayer.isPlaying变为 false。

6。在 #5 的 while 循环中等待时，使用 if ( videoPlayerList[videoIndex].time >= (videoPlayerList[videoIndex].clip.length/2))。如果这是真的，请在列表中的下一个 VideoPlayer 上调用 VideoPlayer.Prepare() 以使其准备就绪。

7.while循环存在后，当前视频播放完毕。播放列表中的下一个 VideoPlayer，然后从 #5 再次重复以准备列表中的下一个 VideoPlayer。

下面的脚本应该完成我上面描述的所有事情。只需创建一个 RawImage 并将其插入图像槽即可。您所有的视频也都添加到 videoClipList 变量中。它应该一个接一个地播放视频，而不需要很长的加载时间。 Debug.Log 很昂贵，所以一旦您确认它工作正常就将其删除。

//Raw Image to Show Video Images [Assign from the Editor]
public RawImage image;
//Set from the Editor
public List<VideoClip> videoClipList;

private List<VideoPlayer> videoPlayerList;
private int videoIndex = 0;


void Start()
{
    StartCoroutine(playVideo());
}

IEnumerator playVideo(bool firstRun = true)
{
    if (videoClipList == null || videoClipList.Count <= 0)
    {
        Debug.LogError("Assign VideoClips from the Editor");
        yield break;
    }

    //Init videoPlayerList first time this function is called
    if (firstRun)
    {
        videoPlayerList = new List<VideoPlayer>();
        for (int i = 0; i < videoClipList.Count; i++)
        {
            //Create new Object to hold the Video and the sound then make it a child of this object
            GameObject vidHolder = new GameObject("VP" + i);
            vidHolder.transform.SetParent(transform);

            //Add VideoPlayer to the GameObject
            VideoPlayer videoPlayer = vidHolder.AddComponent<VideoPlayer>();
            videoPlayerList.Add(videoPlayer);

            //Add AudioSource to  the GameObject
            AudioSource audioSource = vidHolder.AddComponent<AudioSource>();

            //Disable Play on Awake for both Video and Audio
            videoPlayer.playOnAwake = false;
            audioSource.playOnAwake = false;

            //We want to play from video clip not from url
            videoPlayer.source = VideoSource.VideoClip;

            //Set Audio Output to AudioSource
            videoPlayer.audioOutputMode = VideoAudioOutputMode.AudioSource;

            //Assign the Audio from Video to AudioSource to be played
            videoPlayer.EnableAudioTrack(0, true);
            videoPlayer.SetTargetAudioSource(0, audioSource);

            //Set video Clip To Play 
            videoPlayer.clip = videoClipList[i];
        }
    }

    //Make sure that the NEXT VideoPlayer index is valid
    if (videoIndex >= videoPlayerList.Count)
        yield break;

    //Prepare video
    videoPlayerList[videoIndex].Prepare();

    //Wait until this video is prepared
    while (!videoPlayerList[videoIndex].isPrepared)
    {
        Debug.Log("Preparing Index: " + videoIndex);
        yield return null;
    }
    Debug.LogWarning("Done Preparing current Video Index: " + videoIndex);

    //Assign the Texture from Video to RawImage to be displayed
    image.texture = videoPlayerList[videoIndex].texture;

    //Play first video
    videoPlayerList[videoIndex].Play();

    //Wait while the current video is playing
    bool reachedHalfWay = false;
    int nextIndex = (videoIndex + 1);
    while (videoPlayerList[videoIndex].isPlaying)
    {
        Debug.Log("Playing time: " + videoPlayerList[videoIndex].time + " INDEX: " + videoIndex);

        //(Check if we have reached half way)
        if (!reachedHalfWay && videoPlayerList[videoIndex].time >= (videoPlayerList[videoIndex].clip.length / 2))
        {
            reachedHalfWay = true; //Set to true so that we don't evaluate this again

            //Make sure that the NEXT VideoPlayer index is valid. Othereise Exit since this is the end
            if (nextIndex >= videoPlayerList.Count)
            {
                Debug.LogWarning("End of All Videos: " + videoIndex);
                yield break;
            }

            //Prepare the NEXT video
            Debug.LogWarning("Ready to Prepare NEXT Video Index: " + nextIndex);
            videoPlayerList[nextIndex].Prepare();
        }
        yield return null;
    }
    Debug.Log("Done Playing current Video Index: " + videoIndex);

    //Wait until NEXT video is prepared
    while (!videoPlayerList[nextIndex].isPrepared)
    {
        Debug.Log("Preparing NEXT Video Index: " + nextIndex);
        yield return null;
    }

    Debug.LogWarning("Done Preparing NEXT Video Index: " + videoIndex);

    //Increment Video index
    videoIndex++;

    //Play next prepared video. Pass false to it so that some codes are not executed at-all
    StartCoroutine(playVideo(false));
}