播放视频时禁用Android的VideoView requestAudioFocus？

Question

我正在构建一个记录和播放视频的应用程序.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的音频.但是,在Lollipop上,Android的VideoView类会在VideoView.openVideo()调用私有方法时自动请求音频焦点:

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

有关如何绕过这个的任何建议？

Answer 1

从 Android SDK 26 开始，您可能想要使用VideoView和

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

对于旧版本，这里描述了一种解决方法：https : //stackoverflow.com/a/31569930/993439

基本上，复制VideoView以下行的源代码并取消注释

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

Answer 2

android.widget.VideoView我通过复制Lollipop 的整个源代码并删除您提到的行来解决这个问题，这是一个愚蠢的解决方案。

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

我不推荐这样做，因为我认为这是一个临时解决方案。VideoView4.1-5.0 之间发生了很大变化，因此这可能会在 Lollipop 以外的 Android 版本上引发 RuntimeException

编辑

正如pinxue告诉我们的那样，我采用了MediaPlayer + SurfaceView的方法；viewWidth它尊重和内的纵横比viewHeight。

            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");
                }
            }