Android：音频录制与语音级别的可视化

Question

我需要一个创建一个android应用程序，用于录制语音，同时显示语音（声音）级别的可视化。

我已经创建了一个音频录制应用程序，但我无法将其添加到声音级可视化中。我该怎么做？

请别人帮我一个建议或示例教程链接或代码。

Answer 1

检查此链接： http://code.google.com/p/android-labs/source/browse/trunk/NoiseAlert/src/com/google/android/noisealert/SoundMeter.java

它记录音频到/ dev/null的，并检查音量。 但是您可以更改文件名以保留录制的声音。

Answer 2

如果您使用的是MediaRecorder类，并且基于峰值振幅的可视化可以使用，则可以使用getMaxAmplitude()方法连续轮询“自上次调用后采样的最大绝对振幅”。
将幅度缩小到一个索引，该索引确定应用程序的图形音量条点亮并设置的数量。

Answer 3

像这样创建一个xml activity_recording.xml。

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="180dp" 
    android:layout_alignParentBottom="true" 
    android:background="#231f20" > 

    <ali.visualiser.VisualizerView 
     android:id="@+id/visualizer" 
     android:layout_width="220dp" 
     android:layout_height="75dp" 
     android:layout_centerHorizontal="true" 
     android:layout_margin="5dp" /> 

    <TextView 
     android:id="@+id/txtRecord" 
     android:layout_width="wrap_content" 
     android:layout_height="40dp" 
     android:layout_alignParentBottom="true" 
     android:layout_centerHorizontal="true" 
     android:layout_marginBottom="25dp" 
     android:gravity="center" 
     android:text="Start Recording" 
     android:textColor="@android:color/white" 
     android:textSize="30sp" /> 

</RelativeLayout> 

创建如下所示的自定义visualizerView。

package ali.visualiser; 

import java.util.ArrayList; 
import java.util.List; 

import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.util.AttributeSet; 
import android.view.View; 

public class VisualizerView extends View { 
    private static final int LINE_WIDTH = 1; // width of visualizer lines 
    private static final int LINE_SCALE = 75; // scales visualizer lines 
    private List<Float> amplitudes; // amplitudes for line lengths 
    private int width; // width of this View 
    private int height; // height of this View 
    private Paint linePaint; // specifies line drawing characteristics 

    // constructor 
    public VisualizerView(Context context, AttributeSet attrs) { 
     super(context, attrs); // call superclass constructor 
     linePaint = new Paint(); // create Paint for lines 
     linePaint.setColor(Color.GREEN); // set color to green 
     linePaint.setStrokeWidth(LINE_WIDTH); // set stroke width 
    } 

    // called when the dimensions of the View change 
    @Override 
    protected void onSizeChanged(int w, int h, int oldw, int oldh) { 
     width = w; // new width of this View 
     height = h; // new height of this View 
     amplitudes = new ArrayList<Float>(width/LINE_WIDTH); 
    } 

    // clear all amplitudes to prepare for a new visualization 
    public void clear() { 
     amplitudes.clear(); 
    } 

    // add the given amplitude to the amplitudes ArrayList 
    public void addAmplitude(float amplitude) { 
     amplitudes.add(amplitude); // add newest to the amplitudes ArrayList 

     // if the power lines completely fill the VisualizerView 
     if (amplitudes.size() * LINE_WIDTH >= width) { 
      amplitudes.remove(0); // remove oldest power value 
     } 
    } 

    // draw the visualizer with scaled lines representing the amplitudes 
    @Override 
    public void onDraw(Canvas canvas) { 
     int middle = height/2; // get the middle of the View 
     float curX = 0; // start curX at zero 

     // for each item in the amplitudes ArrayList 
     for (float power : amplitudes) { 
      float scaledHeight = power/LINE_SCALE; // scale the power 
      curX += LINE_WIDTH; // increase X by LINE_WIDTH 

      // draw a line representing this item in the amplitudes ArrayList 
      canvas.drawLine(curX, middle + scaledHeight/2, curX, middle 
        - scaledHeight/2, linePaint); 
     } 
    } 

} 

创建RecordingActivity类，如下所示。

package ali.visualiser;

import java.io.File; 
import java.io.IOException; 

import android.app.Activity; 
import android.media.MediaRecorder; 
import android.media.MediaRecorder.OnErrorListener; 
import android.media.MediaRecorder.OnInfoListener; 
import android.os.Bundle; 
import android.os.Environment; 
import android.os.Handler; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.TextView; 



public class RecordingActivity extends Activity { 
    public static final String DIRECTORY_NAME_TEMP = "AudioTemp"; 
    public static final int REPEAT_INTERVAL = 40; 
    private TextView txtRecord; 

    VisualizerView visualizerView; 

    private MediaRecorder recorder = null; 

    File audioDirTemp; 
private boolean isRecording = false; 


    private Handler handler; // Handler for updating the visualizer 
    // private boolean recording; // are we currently recording? 

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

     visualizerView = (VisualizerView) findViewById(R.id.visualizer); 

     txtRecord = (TextView) findViewById(R.id.txtRecord); 
     txtRecord.setOnClickListener(recordClick); 

     audioDirTemp = new File(Environment.getExternalStorageDirectory(), 
       DIRECTORY_NAME_TEMP); 
     if (audioDirTemp.exists()) { 
      deleteFilesInDir(audioDirTemp); 
     } else { 
      audioDirTemp.mkdirs(); 
     } 

     // create the Handler for visualizer update 
     handler = new Handler(); 
    } 

    OnClickListener recordClick = new OnClickListener() { 

     @Override 
     public void onClick(View v) { 

      if (!isRecording) { 
       // isRecording = true; 

       txtRecord.setText("Stop Recording"); 

       recorder = new MediaRecorder(); 

       recorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
       recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
       recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
       recorder.setOutputFile(audioDirTemp + "/audio_file" 
         + ".mp3"); 

       OnErrorListener errorListener = null; 
       recorder.setOnErrorListener(errorListener); 
       OnInfoListener infoListener = null; 
       recorder.setOnInfoListener(infoListener); 

       try { 
        recorder.prepare(); 
        recorder.start(); 
        isRecording = true; // we are currently recording 
       } catch (IllegalStateException e) { 
        e.printStackTrace(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
       handler.post(updateVisualizer); 

      } else { 

       txtRecord.setText("Start Recording"); 

       releaseRecorder(); 
      } 

     } 
    }; 

    private void releaseRecorder() { 
     if (recorder != null) { 
      isRecording = false; // stop recording 
      handler.removeCallbacks(updateVisualizer); 
      visualizerView.clear(); 
      recorder.stop(); 
      recorder.reset(); 
      recorder.release(); 
      recorder = null; 
     } 
    } 

    public static boolean deleteFilesInDir(File path) { 

     if(path.exists()) { 
      File[] files = path.listFiles(); 
      if (files == null) { 
       return true; 
      } 
      for(int i=0; i<files.length; i++) { 

       if(files[i].isDirectory()) {     

       } 
       else { 
        files[i].delete(); 
       } 
      } 
     } 
     return true; 
    } 

    @Override 
    protected void onDestroy() { 

     super.onDestroy(); 
     releaseRecorder(); 
    } 

    // updates the visualizer every 50 milliseconds 
    Runnable updateVisualizer = new Runnable() { 
     @Override 
     public void run() { 
      if (isRecording) // if we are already recording 
      { 
       // get the current amplitude 
       int x = recorder.getMaxAmplitude(); 
       visualizerView.addAmplitude(x); // update the VisualizeView 
       visualizerView.invalidate(); // refresh the VisualizerView 

       // update in 40 milliseconds 
       handler.postDelayed(this, REPEAT_INTERVAL); 
      } 
     } 
    }; 


} 

结果

这是它的外观： https://www.youtube.com/watch?v=BoFG6S02GH0

当它到达终点，动画继续按预期：擦除图形的开始。

Answer 4

我喜欢阿里的答案，但这里有一个更简单的版本，表现更好。

我启动了我的RecordingActivity并将其设置为全屏，但您可以创建布局资源或在任何位置添加视图。

RecordingActivity with Fullscreen View

public class RecordingActivity extends Activity { 
    private VisualizerView visualizerView; 
    private MediaRecorder recorder = new MediaRecorder(); 
    private Handler handler = new Handler(); 
    final Runnable updater = new Runnable() { 
     public void run() { 
      handler.postDelayed(this, 1); 
      int maxAmplitude = recorder.getMaxAmplitude(); 
      if (maxAmplitude != 0) { 
       visualizerView.addAmplitude(maxAmplitude); 
      } 
     } 
    }; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_recording); 
     visualizerView = (VisualizerView) findViewById(R.id.visualizer); 
     try { 
      recorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
      recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP); 
      recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
      recorder.setOutputFile("/dev/null"); 
      recorder.prepare(); 
      recorder.start(); 
     } catch (IllegalStateException | IOException ignored) { 
     } 
    } 

    @Override 
    protected void onDestroy() { 
     super.onDestroy(); 
     handler.removeCallbacks(updater); 
     recorder.stop(); 
     recorder.reset(); 
     recorder.release(); 
    } 

    @Override 
    public void onWindowFocusChanged(boolean hasFocus) { 
     super.onWindowFocusChanged(hasFocus); 
     handler.post(updater); 
    } 
} 

视图类的OnDraw方法应该是尽可能快。

public class VisualizerView extends View { 
    private static final int MAX_AMPLITUDE = 32767; 

    private float[] amplitudes; 
    private float[] vectors; 
    private int insertIdx = 0; 
    private Paint pointPaint; 
    private Paint linePaint; 
    private int width; 
    private int height; 

    public VisualizerView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     linePaint = new Paint(); 
     linePaint.setColor(Color.GREEN); 
     linePaint.setStrokeWidth(1); 
     pointPaint = new Paint(); 
     pointPaint.setColor(Color.BLUE); 
     pointPaint.setStrokeWidth(1); 
    } 

    @Override 
    protected void onSizeChanged(int width, int h, int oldw, int oldh) { 
     this.width = width; 
     height = h; 
     amplitudes = new float[this.width * 2]; // xy for each point across the width 
     vectors = new float[this.width * 4]; // xxyy for each line across the width 
    } 

    /** 
    * modifies draw arrays. cycles back to zero when amplitude samples reach max screen size 
    */ 
    public void addAmplitude(int amplitude) { 
     invalidate(); 
     float scaledHeight = ((float) amplitude/MAX_AMPLITUDE) * (height - 1); 
     int ampIdx = insertIdx * 2; 
     amplitudes[ampIdx++] = insertIdx; // x 
     amplitudes[ampIdx] = scaledHeight; // y 
     int vectorIdx = insertIdx * 4; 
     vectors[vectorIdx++] = insertIdx; // x0 
     vectors[vectorIdx++] = 0;   // y0 
     vectors[vectorIdx++] = insertIdx; // x1 
     vectors[vectorIdx] = scaledHeight; // y1 
     // insert index must be shorter than screen width 
     insertIdx = ++insertIdx >= width ? 0 : insertIdx; 
    } 

    @Override 
    public void onDraw(Canvas canvas) { 
     canvas.drawLines(vectors, linePaint); 
     canvas.drawPoints(amplitudes, pointPaint); 
    } 
}