Android - 在 VideoView 中播放 MP4 - 没有视频但有音频(Z 顺序不起作用) [英] Android - Playing MP4 in VideoView - no video but audio (Z-Order Doesn't Work)

问题描述

我正在尝试做一个在 VideoView 中播放 MP4 的简单测试，但我只能听到音频.我已经按照其他帖子中的建议尝试了 Z 顺序技巧，但没有奏效.

I'm trying to do a simple test playing an MP4 in a VideoView, but I can only hear audio. I've already tried the Z-order trick as suggested in other posts, but it didn't work.

TestLayout.axml:

TestLayout.axml:

     <?xml version="1.0" encoding="utf-8"?>
        <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/testLayout"
            android:clipChildren="false">
                <VideoView
                android:id="@+id/testVideo"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:visibility="visible"/>
  <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:paddingLeft="10dp"
    android:paddingRight="20dp"
    android:paddingTop="170dp"
    android:paddingBottom="100dp"
    android:clipChildren="false"
    android:clipToPadding="false">
      <ImageButton
        android:id="@+id/play"
        android:layout_height="20dp"
        android:layout_width="60dp"
        android:background="@android:color/transparent"
        android:adjustViewBounds="false"
        android:src="@drawable/play"
        android:scaleType="fitXY"
        android:padding="0dp"/>
</LinearLayout>
        </RelativeLayout>

TestActivity.cs(按钮触发代码):

TestActivity.cs (button trigger code):

    var videoView = (VideoView)FindViewById(Resource.Id.testVideo);
    videoView.SetVideoURI(Android.Net.Uri.Parse("android.resource://" + PackageName + "/" +Resource.Raw.testVideo));
    videoView.SetMediaController(null);
    videoView.RequestFocus();
    ISurfaceHolder holder = videoView.Holder;
    holder.SetType(SurfaceType.PushBuffers);
    videoView.Start();
    videoView.SetZOrderMediaOverlay(true);
    videoView.SetZOrderOnTop(true);

还有其他建议吗?

MP4 是使用 Photoshop 编码的 H.264，大小为 320x240.

MP4 is H.264 encoded using Photoshop and is 320x240.

推荐答案

有很多因素需要审查.

• 如果您听到音频，则视频正在播放，但视频未按预期解码和显示.

• If you are hearing the audio, the video is playing, but the video is not being decoded and displayed as expected.

这是在模拟器还是物理设备上发生的?

Is this happening on an emulator or physical device?

• 如果是模拟器，请在物理设备上重新测试

您是否在使用 H.264 基线配置文件 用于编码的编解码器?

Are you using a H.264 Baseline Profile codec for encoding?

• 不同的应用产生不同版本的 H.264，尝试通过不同的应用进行编码，即 ffmpeg

什么 Android API 版本?

What Android API version?

• 不同的版本支持不同的编解码器，查看 Android 文档

实施 MediaPlayer.IOnInfoListener 和 MediaPlayer.IOnErrorListener 并检查您的 MediaInfo 和 MediaError可能会得到.

Implement MediaPlayer.IOnInfoListener and MediaPlayer.IOnErrorListener and review the MediaInfo and MediaError that you might be getting.

注意:我发现 Xamarin 的 Android 播放器在 Genymotion 上播放良好的视频上失败，AVD 和 BlueStacks 也是如此.最后在物理设备上测试

Note: I have found that Xamarin's Android Player fails on videos that play fine on Genymotion, same goes for AVD and BlueStacks. In the end, test on physical devices

创建一个简单的测试应用来测试您的视频并查看OnError 和 OnInfo 参数.

Create a simple test app for testing your videos and review the OnError and OnInfo parameters.

[Activity(Label = "DroidVideo", MainLauncher = true, Icon = "@mipmap/icon")]
public class MainActivity : Activity, MediaPlayer.IOnInfoListener, MediaPlayer.IOnErrorListener
{
    public bool OnError(MediaPlayer mp, [GeneratedEnum] MediaError what, int extra)
    {
        Log.Debug("Media", what.ToString());
        return true;
    }

    public bool OnInfo(MediaPlayer mp, [GeneratedEnum] MediaInfo what, int extra)
    {
        Log.Info("Media", what.ToString());
        return true;
    }

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.Main);

        Button button = FindViewById<Button>(Resource.Id.myButton);
        button.Click += delegate { 
            VideoView video = FindViewById<VideoView>(Resource.Id.myVideo);
            video.SetOnInfoListener(this);
            var videoUri = Android.Net.Uri.Parse("android.resource://" + Path.Combine(PackageName, "raw", Resource.Raw.pool.ToString()));
            video.SetVideoURI(videoUri);
            video.Start();
        };
    }
}

示例布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:id="@+id/myButton"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <VideoView
        android:id="@+id/myVideo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
            />
</LinearLayout>

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