没有RECORD_AUDIO的Android Visualizer使用权限

Question

我正在使用一个简单的Visualizer类（见下文）来显示MediaPlayer类的音频输出。但是，这需要android.permission.RECORD_AUDIO，这似乎吓跑了用户。有没有办法达到相同的结果，但不是android.permission.RECORD_AUDIO？

展示台代码：

private void setupVisualizerFx() {
    int audioSessionId = service.getAudioSessionId();
    if (mVisualizer != null) {
        mVisualizer.setEnabled(false);
    }
    mVisualizer = new Visualizer(audioSessionId);
    mVisualizer.setEnabled(false);
    try {
        mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
    } catch (IllegalStateException e) {
        e.printStackTrace();
    }
    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);
}

/**
 * A simple class that draws waveform data received from a
 * {@link Visualizer.OnDataCaptureListener#onWaveFormDataCapture }
 */
class VisualizerView extends View {
    private byte[] mBytes;
    private float[] mPoints;
    private Rect mRect = new Rect();

    private Paint mForePaint = new Paint();

    public VisualizerView(Context context) {
        super(context);
        init();

    }

    private void init() {
        mBytes = null;

        SharedPreferences sharedPref = PreferenceManager
                .getDefaultSharedPreferences(getContext());
        String txtColorString = sharedPref.getString(
                PreferencesActivity.KEY_PREF_TXT_COLOR, "");
        int txtColor = Integer.parseInt(txtColorString);

        mForePaint.setStrokeWidth(1f);
        mForePaint.setAntiAlias(true);
        mForePaint.setColor(txtColor);
    }

    public void updateVisualizer(byte[] bytes) {
        mBytes = bytes;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if (mBytes == null) {
            return;
        }

        if (mPoints == null || mPoints.length < mBytes.length * 4) {
            mPoints = new float[mBytes.length * 4];
        }

        mRect.set(0, 0, getWidth(), getHeight());

        for (int i = 0; i < mBytes.length - 1; i++) {
            mPoints[i * 4] = mRect.width() * i / (mBytes.length - 1);
            mPoints[i * 4 + 1] = mRect.height() / 2
                    + ((byte) (mBytes[i] + 128)) * (mRect.height() / 2)
                    / 128;
            mPoints[i * 4 + 2] = mRect.width() * (i + 1)
                    / (mBytes.length - 1);
            mPoints[i * 4 + 3] = mRect.height() / 2
                    + ((byte) (mBytes[i + 1] + 128)) * (mRect.height() / 2)
                    / 128;
        }

        canvas.drawLines(mPoints, mForePaint);
    }
}

对Visualizer类的任何其他建议？