java.lang.RuntimeException：无法初始化 Visualizer 引擎，错误：-4

Question

在 API 16 上运行应用程序时出现以下错误。

 java.lang.RuntimeException: Unable to start activity ComponentInfo{}: java.lang.RuntimeException: Cannot initialize Visualizer engine, error: -4
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
                      at android.app.ActivityThread.access$600(ActivityThread.java:130)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
                      at android.os.Handler.dispatchMessage(Handler.java:99)
                      at android.os.Looper.loop(Looper.java:137)
                      at android.app.ActivityThread.main(ActivityThread.java:4745)
                      at java.lang.reflect.Method.invokeNative(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:511)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
                      at dalvik.system.NativeStart.main(Native Method)
                   Caused by: java.lang.RuntimeException: Cannot initialize Visualizer engine, error: -4
                      at android.media.audiofx.Visualizer.<init>(Visualizer.java:199)
                      at xyz.activity.AudioPreviewActivity.setupVisualizerFxAndUI(AudioPreviewActivity.java:83)
                      at xyz.activity.AudioPreviewActivity.initAudio(AudioPreviewActivity.java:60)
                      at xyz.activity.AudioPreviewActivity.onCreate(AudioPreviewActivity.java:40)
                      at android.app.Activity.performCreate(Activity.java:5008)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 
                      at android.app.ActivityThread.access$600(ActivityThread.java:130) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 
                      at android.os.Handler.dispatchMessage(Handler.java:99) 
                      at android.os.Looper.loop(Looper.java:137) 
                      at android.app.ActivityThread.main(ActivityThread.java:4745) 
                      at java.lang.reflect.Method.invokeNative(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:511) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
                      at dalvik.system.NativeStart.main(Native Method)   

错误线-

mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());

代码

private void setupVisualizerFxAndUI() {

    mMediaPlayer = MediaPlayer.create(this, Uri.parse(filePath));
    mMediaPlayer
            .setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                public void onCompletion(MediaPlayer mediaPlayer) {
                    mVisualizer.setEnabled(false);
                }
            });

    mMediaPlayer.start();
    mMediaPlayer.setLooping(true);
    mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());
    mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
    mVisualizer.setDataCaptureListener(
                    new Visualizer.OnDataCaptureListener() {
                        public void onWaveFormDataCapture(Visualizer visualizer,
                                                          byte[] bytes, int samplingRate) {
                            mVisualizerView.updateVisualizer(bytes);
                        }

                        public void onFftDataCapture(Visualizer visualizer,
                                                     byte[] bytes, int samplingRate) {
                        }
                    }, Visualizer.getMaxCaptureRate() / 2, true, false);
        }

我已经在清单中添加了以下权限-

<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>

Answer 1

-4 表示您提供了错误的参数。虽然 getAudioSessionId 可以在任何状态下调用，但您是否在正在使用的 MediaPlayer 上调用了prepare 和start，以确保它在尝试可视化之前具有良好的状态？

您可能还需要在以这种方式使用 Visualiser 时添加 android.permission.RECORD_AUDIO 权限，如果音频源不是本地的，则可能还需要添加 android.permission.INTERNET

Answer 2

为 api 23 及更高版本添加运行时权限。

if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {

            int hasAudioPermission = checkSelfPermission(Manifest.permission.RECORD_AUDIO);
            int hasInternetPermission = checkSelfPermission(Manifest.permission.INTERNET);

            List<String> permissions = new ArrayList<>();


      if (hasAudioPermission != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.RECORD_AUDIO);
            }

            if (hasInternetPermission != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.INTERNET);
            }

            if (!permissions.isEmpty()) {
                requestPermissions(permissions.toArray(new String[permissions.size()]), PERMISSION);
            }
        }

Answer 3

很可能您有 Visualizer 的 bad in the configuration 的内容，请仔细检查您的 setupVisualizer 方法中的内容。请参考similar issue。

Answer 4

迟到的答案，但仍然。

问题与权限无关，正如您所说，您针对 API 16 并在清单中添加了权限，因此 A.N.T 的回答甚至没有意义。

问题是你在MediaPlayer 准备好之前调用了Visualizer。

---

您可以在准备好mMediaPlayer 后调用它来解决此问题，如下所示：

private void setupMediaPlayer(String filePath) {

    mMediaPlayer = MediaPlayer.create(this, Uri.parse(filePath));

    //Check when MediaPlayer is completed
    mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener(){
        public void onCompletion(MediaPlayer mediaPlayer) {
            mVisualizer.setEnabled(false);
        }
    });

    //Check when MediaPlayer is prepared
    mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
        @Override
        public void onPrepared(MediaPlayer mediaPlayer) {
            //MediaPlayer is prepared and playback can now start
            startPlaying();

        }
    });

}

一旦mMediaPlayer 准备好：

private void startPlaying() {
    mMediaPlayer.start();
    mMediaPlayer.setLooping(true);
    //Now we can call the Visualizer
    createVisualizer();
}

然后你可以像这样拨打Visualizer：

private void createVisualizer() {
    mVisualizer = new Visualizer(mMediaPlayer.getAudioSessionId());
    mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
    mVisualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {
        @Override
        public void onWaveFormDataCapture(Visualizer visualizer, byte[] waveform, int samplingRate) {
            mVisualizerView.updateVisualizer(bytes);
        }

        public void onFftDataCapture(Visualizer visualizer, byte[] bytes, int samplingRate) {
            //Do something you like
        }

    }, Visualizer.getMaxCaptureRate() / 2, true, false);

}