Android:从MediaRecorder使用getMaxAmplitude()，同时从TarsosDSP使用PercussionOnsetDetector

Question

我试图从它检测到的每一个拍击声中获得振幅读数，但每次它检测到拍击声时，我都会从getMaxAmplitude()获得IllegalStateException或0。我做错什么了吗？有什么办法可以解决这个问题吗？请让我知道!

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //Checks Permission
    checkPermission(Manifest.permission.RECORD_AUDIO,REQUEST_RECORD_AUDIO_PERMISSION);

    double threshold = 8;
    double sensitivity = 45;

    PercussionOnsetDetector mPercussionDetector = new PercussionOnsetDetector(22050, 1024,
            new OnsetHandler() {

                @Override
                public void handleOnset(double time, double salience) {
                   /* try {
                        new MediaRecorder().setAudioSource(MediaRecorder.AudioSource.MIC);
                        new MediaRecorder().setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                        new MediaRecorder().setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
                        new MediaRecorder().setOutputFile("dev/null");
                        new MediaRecorder().prepare();
                        new MediaRecorder().start();
                    } catch (Exception e) {
                        e.printStackTrace();
                    } */

                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {

                            System.out.println(new MediaRecorder().getMaxAmplitude());
                            System.out.println("YAAAYYY");
                        }
                    });
                }
            }, sensitivity, threshold);

    dispatcher.addAudioProcessor(mPercussionDetector);
    new Thread(dispatcher,"Audio Dispatcher").start();
}

Answer 1

检查javadoc for MediaRecorder#getMaxAmplitude method

它说setAudioSource方法应该在调用之前调用。

请注意本javadoc开头的状态和使用示例。getMaxAmplitude只是一个getter，它不执行实际的记录。