Question

我正在构建一个记录和播放视频的应用。我想在不影响背景音乐播放的情况下这样做，即如果我开始播放视频，我不想暂停其他应用程序＆＃39;音频。但是，在Lollipop上，当调用私有方法VideoView.openVideo()时，Android的VideoView类会自动请求音频焦点：

AudioManager am = (AudioManager) super.getSystemService(name);
am.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);

有关如何解决此问题的任何建议？

Answer 1

我通过复制Lollipop android.widget.VideoView的完整源代码并删除你提到的行来解决这个问题。

制作自己的VideoView课程。不要使用extends VideoView，因为您无法覆盖openVideo()方法。

我不建议这样做，因为我认为这是一个临时解决方案。 VideoView在4.1-5.0之间改变很多，所以这可以在除Lollipop之外的Android版本上进行RuntimeException

修改

当pinxue告诉我们时，我接近了MediaPlayer + SurfaceView; 它尊重viewWidth和viewHeight中的宽高比。

final String finalFilePath = filePath; final SurfaceHolder surfaceHolder = sv.getHolder(); final MediaPlayer mediaPlayer = new MediaPlayer(); final LinearLayout.LayoutParams svLayoutParams = new LinearLayout.LayoutParams(viewWidth,viewHeight); surfaceHolder.addCallback(new SurfaceHolder.Callback(){ @Override public void surfaceCreated(SurfaceHolder holder) { try { if(isDebug) { System.out.println("setting VideoPath to VideoView: "+finalFilePath); } mediaPlayer.setDataSource(finalFilePath); }catch (IOException ioe){ if(isDebug){ ioe.printStackTrace(); } //mediaPlayer = null; } mediaPlayer.setDisplay(surfaceHolder); mediaPlayer.prepareAsync(); mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() { @Override public void onPrepared(MediaPlayer mp) { if(isDebug){ System.out.println("Video is starting..."); } // for compatibility, we adjust size based on aspect ratio if ( mp.getVideoWidth() * svLayoutParams.height < svLayoutParams.width * mp.getVideoHeight() ) { //Log.i("@@@", "image too wide, correcting"); svLayoutParams.width = svLayoutParams.height * mp.getVideoWidth() / mp.getVideoHeight(); } else if ( mp.getVideoWidth() * svLayoutParams.height > svLayoutParams.width * mp.getVideoHeight() ) { //Log.i("@@@", "image too tall, correcting"); svLayoutParams.height = svLayoutParams.width * mp.getVideoHeight() / mp.getVideoWidth(); } sv.post(new Runnable(){ @Override public void run() { sv.setLayoutParams(svLayoutParams); } }); mp.start(); } }); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { if(isDebug){ System.out.println("surfaceChanged(holder, "+format+", "+width+", "+height+")"); } } @Override public void surfaceDestroyed(SurfaceHolder holder) { try { mediaPlayer.setDataSource(""); }catch (IOException ioe){ if(isDebug){ ioe.printStackTrace(); } } } }); if(sv.post(new Runnable() { @Override public void run() { sv.setLayoutParams(svLayoutParams);/// sv.setVisibility(View.VISIBLE); }})){ if(isDebug) { System.out.println("post Succeded"); } }else{ if(isDebug) { System.out.println("post Failed"); } }

Answer 2

从Android SDK 26开始，您可能要使用VideoView和

if(Build.VERSION.SDK_INT >= Build.Version_CODES.O){
     //set this BEFORE start playback
     videoView.setAudioFocusRequest(AudioManager.AUDIOFOCUS_NONE)
}

对于较旧的版本，这里描述了一种解决方法：https://stackoverflow.com/a/31569930/993439

基本上，复制VideoView的源代码，并在下面的行中取消注释

AudioManager am = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
am.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);

Answer 3

您可以使用MediaPlayer + SurfaceView。

Answer 4

已接受的解决方案并不能保证所有Android版本的兼容性，并且是一个肮脏的黑客而不是真正的解决方案。我尝试过所有形式的黑客工作，但没有一个能让我满意。

我已经提出了一个更好的解决方案 - 从VideoView切换到TextureView并使用MediaPlayer加载它。用户的观点没有区别，只是没有音频停止。

这是我播放MP4循环的用例：

private TextureView _introVideoTextureView;
private MediaPlayer _introMediaPlayer;

...

@Override
public void onCreate(...) {
    _introVideoTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
           try {
               destoryIntroVideo();

               _introMediaPlayer = MediaPlayer.create(SignInActivity.this, R.raw.intro_video);
               _introMediaPlayer.setSurface(new Surface(surfaceTexture));
               _introMediaPlayer.setLooping(true);
               _introMediaPlayer.setVideoScalingMode(MediaPlayer.VIDEO_SCALING_MODE_SCALE_TO_FIT_WITH_CROPPING);
               _introMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mediaPlayer) {
                        mediaPlayer.start();
                    }
                });

            } catch (Exception e) {
                System.err.println("Error playing intro video: " + e.getMessage());
            }
        }

        @Override
        public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {}

        @Override
        public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
            return false;
        }

        @Override
        public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {}
    });
}

@Override
public void onDestroy() {
    super.onDestroy();

    destoryIntroVideo();
}

private void destoryIntroVideo() {
    if (_introMediaPlayer != null) {
        _introMediaPlayer.stop();
        _introMediaPlayer.release();
        _introMediaPlayer = null;
    }
}

Answer 5

使用audioManager.abandonAudioFocus（null）

如果您查看VideoView代码，您会注意到它为OnAudioFocusChangeListener调用了带有null的方法audioManager.requestAudioFocus。当您使用AudioManager注册侦听器时，它使用此方法为侦听器创建ID

private String getIdForAudioFocusListener(OnAudioFocusChangeListener l) {
    if (l == null) {
        return new String(this.toString());
    } else {
        return new String(this.toString() + l.toString());
    }
}

每次使用null时都会生成相同的ID。因此，如果您使用null调用abandonAudioFocus，它将删除任何添加了null的侦听器作为OnAudioFocusChangeListener的参数

播放视频时禁用Android的VideoView requestAudioFocus？

5 个答案: