如何处理展示台对象的 onWaveFormDataCapture 结果？

Question 1

我是安卓编程和音频可视化方面的新手。我想创建一个简单的音频可视化器，使用 MediaPlayer 和 Visualizer 班级。我的问题是，我不知道 wave form data 到底是什么。我必须用它来实现音频的可视化吗？我正在使用下面的代码。它的问题是，它只能将文件的前10-12秒的音频可视化；之后，我就无法捕捉到更多的数据了!我哪里做错了？

public void attachVisualizer()
    Visualizer vis = new Visualizer(mPlayer.getAudioSessionId());
    vis.setCaptureSize(Visualizer.getCaptureSizeRange()[0]);
    vis.setDataCaptureListener(new Visualizer.OnDataCaptureListener() {
        public void onWaveFormDataCapture(Visualizer visualizer, byte[] bytes, int samplingRate) {
            int sum = 0;
            for(int i = 0; i < bytes.length; i++) {
                sum += bytes[i];
            if(sum > 8000) {
                // Do something which uses mPlayer.getCurrentPosition() in mathematics
        public void onFftDataCapture(Visualizer visualizer, byte[] fft, int samplingRate) {}
    }, Visualizer.getMaxCaptureRate() , true, false);
    vis.setEnabled(true);
而我心中的另一个问题是，我如何记录某个音频片段中包含的时间长度？

Question 2


          
           i do this:
          
          visualizer = new Visualizer(0);
    visualizer.setEnabled(false);
    visualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[0]);
    visualizer.setDataCaptureListener(
            new Visualizer.OnDataCaptureListener() {
                public void onWaveFormDataCapture(Visualizer visualizer,
                        byte[] bytes, int samplingRate) {
                    eqview.setVSWaveForm(bytes);
                public void onFftDataCapture(Visualizer visualizer,
                        byte[] bytes, int samplingRate) {
                    fftview.setVSFftData(bytes);
            }, Visualizer.getMaxCaptureRate(), true, true);
    visualizer.setEnabled(true);
对于展示台视图，我在网上找到了这段代码，我没有写它。
package app.util;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
* @author yokmama
public class VisualizerView extends View {
private byte[] mBytes;
private float[] mPoints;
private Rect mRect = new Rect();
//SharedPreferences prefs;
private Paint mForePaint = new Paint();
public VisualizerView(Context context, AttributeSet attrs) {
    super(context, attrs);
    //prefs = PreferenceManager.getDefaultSharedPreferences(context);
    init();
private void init() {
    mBytes = null;
    //int colorchosen = prefs.getInt("COLOR_PREFERENCE_KEY",
    //      Color.WHITE);
    mForePaint.setStrokeWidth(1);
    //mForePaint.setAntiAlias(true);
    mForePaint.setColor(Color.WHITE);
    //mForePaint.setMaskFilter(new BlurMaskFilter(1, Blur.INNER));
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);