使用新的 Unity VideoPlayer 和 VideoClip API 播放视频

Question

MovieTexture 在 Unity 5.6.0b1 发布后最终被弃用，现在发布了在桌面和移动设备上播放视频的新 API。

VideoPlayer 和 VideoClip 可用于播放视频并在需要时检索每一帧的纹理。

我已设法让视频正常工作，但在 Windows 10 上的编辑器中也无法播放音频。有人知道为什么音频无法播放吗？

//Raw Image to Show Video Images [Assign from the Editor]
public RawImage image;
//Video To Play [Assign from the Editor]
public VideoClip videoToPlay;

private VideoPlayer videoPlayer;
private VideoSource videoSource;

//Audio
private AudioSource audioSource;

// Use this for initialization
void Start()
{
    Application.runInBackground = true;
    StartCoroutine(playVideo());
}

IEnumerator playVideo()
{
    //Add VideoPlayer to the GameObject
    videoPlayer = gameObject.AddComponent<VideoPlayer>();

    //Add AudioSource
    audioSource = gameObject.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 video To Play then prepare Audio to prevent Buffering
    videoPlayer.clip = videoToPlay;
    videoPlayer.Prepare();

    //Wait until video is prepared
    while (!videoPlayer.isPrepared)
    {
        Debug.Log("Preparing Video");
        yield return null;
    }

    Debug.Log("Done Preparing Video");

    //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);

    //Assign the Texture from Video to RawImage to be displayed
    image.texture = videoPlayer.texture;

    //Play Video
    videoPlayer.Play();

    //Play Sound
    audioSource.Play();

    Debug.Log("Playing Video");
    while (videoPlayer.isPlaying)
    {
        Debug.LogWarning("Video Time: " + Mathf.FloorToInt((float)videoPlayer.time));
        yield return null;
    }

    Debug.Log("Done Playing Video");
}

Answer 1

发现问题。下面是播放视频和音频的FIXED代码：

//Raw Image to Show Video Images [Assign from the Editor]
public RawImage image;
//Video To Play [Assign from the Editor]
public VideoClip videoToPlay;

private VideoPlayer videoPlayer;
private VideoSource videoSource;

//Audio
private AudioSource audioSource;

// Use this for initialization
void Start()
{
    Application.runInBackground = true;
    StartCoroutine(playVideo());
}

IEnumerator playVideo()
{
    //Add VideoPlayer to the GameObject
    videoPlayer = gameObject.AddComponent<VideoPlayer>();

    //Add AudioSource
    audioSource = gameObject.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 To Play then prepare Audio to prevent Buffering
    videoPlayer.clip = videoToPlay;
    videoPlayer.Prepare();

    //Wait until video is prepared
    while (!videoPlayer.isPrepared)
    {
        Debug.Log("Preparing Video");
        yield return null;
    }

    Debug.Log("Done Preparing Video");

    //Assign the Texture from Video to RawImage to be displayed
    image.texture = videoPlayer.texture;

    //Play Video
    videoPlayer.Play();

    //Play Sound
    audioSource.Play();

    Debug.Log("Playing Video");
    while (videoPlayer.isPlaying)
    {
        Debug.LogWarning("Video Time: " + Mathf.FloorToInt((float)videoPlayer.time));
        yield return null;
    }

    Debug.Log("Done Playing Video");
}

为什么没有播放音频：

//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);

必须在videoPlayer.Prepare(); 之前而不是之后调用。这需要数小时的实验才能发现这是我遇到的问题。

---

卡在“准备视频”？

在调用videoPlayer.Prepare(); 后等待 5 秒，然后退出 while 循环。

替换：

while (!videoPlayer.isPrepared)
{
    Debug.Log("Preparing Video");
    yield return null;
}

与：

//Wait until video is prepared
WaitForSeconds waitTime = new WaitForSeconds(5);
while (!videoPlayer.isPrepared)
{
    Debug.Log("Preparing Video");
    //Prepare/Wait for 5 sceonds only
    yield return waitTime;
    //Break out of the while loop after 5 seconds wait
    break;
}

这应该可以，但您可能会在视频开始播放时遇到缓冲。在使用这个临时修复时，我的建议是提交标题为“videoPlayer.isPrepared always true”的错误，因为这是一个错误。

一些people 也通过更改修复了它：

videoPlayer.playOnAwake = false; 
audioSource.playOnAwake = false;

到

videoPlayer.playOnAwake = true; 
audioSource.playOnAwake = true;

---

从 URL 播放视频：

替换：

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

与：

//We want to play from url
videoPlayer.source = VideoSource.Url;
videoPlayer.url = "http://www.quirksmode.org/html5/videos/big_buck_bunny.mp4";

然后删除：

public VideoClip videoToPlay; 和 videoPlayer.clip = videoToPlay; 因为它们不再需要了。

从 StreamingAssets 文件夹播放视频：

string url = "file://" + Application.streamingAssetsPath + "/" + "VideoName.mp4";

if !UNITY_EDITOR && UNITY_ANDROID
    url = Application.streamingAssetsPath + "/" + "VideoName.mp4";
#endif

//We want to play from url
videoPlayer.source = VideoSource.Url;
videoPlayer.url = url;

---

所有支持的视频格式：

• ogv
• vp8
• 网站
• 电影
• dv
• mp4
• m4v
• mpg
• mpeg

Windows 上额外支持的视频格式：

• avi
• asf
• wmf

其中一些格式不适用于某些平台。有关支持的视频格式的更多信息，请参阅 this 帖子。

Answer 2

与其他答案所说的类似。您可以在准备和结束视频状态时使用回调。而不是使用协程和yield return。

videoPlayer.loopPointReached += EndReached;
videoPlayer.prepareCompleted += PrepareCompleted;

void PrepareCompleted(VideoPlayer vp) {
    vp.Play();
}

void EndReached(VideoPlayer vp) {
    // do something
}

Answer 3

我使用 @Programmer 的答案从 URL 播放视频，但我无法播放任何声音。最终我在the comments of a YouTube tutorial.找到了答案

要让通过 URL 加载的电影播放音频，您需要在调用 EnableAudioTrack 之前添加以下行：

videoPlayer.controlledAudioTrackCount = 1;

Answer 4

到现在为止，VideoPlayer 应该已经足够更新，您无需编写代码即可正常工作。以下是我发现效果最理想的设置：

这些设置是：

视频播放器：

• 在清醒状态下播放：正确
• 等待第一帧：错误
• 音频输出模式：无

音源：

• 在清醒状态下播放：正确

不要忘记为 VideoPlayer 设置一个 VideoClip，为 AudioSource 设置一个 AudioClip。我发现效果最好的文件格式是用于视频的 .ogv 和用于音频的 .wav。