Android可以通过MediaRecorder和AudioRecord这两个工具来实现录音，MediaRecorder直接把麦克风的数据存到文件，并且能够直接进行编码(如AMR,MP3等)，而AudioRecord则是读取麦克风的音频流。本文使用AudioRecord读取音频流，使用AudioTrack播放音频流，通过“边读边播放”以及增大音量的方式来实现一个简单的助听器程序。

       PS：由于目前的Android模拟器还不支持AudioRecord，因此本程序需要编译之后放到真机运行。

       先贴出本文程序运行截图：

Android提高21篇之十：AudioRecord实现助听器

       PS：程序音量调节只是程序内部调节音量而已，要调到最大音量还需要手动设置系统音量。

       使用AudioRecord必须要申请许可，在AndroidManifest.xml里面添加这句：

       main.xml的源码如下：

XML/HTML代码
  1. <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"   
  2.         android:orientation="vertical" android:layout_width="fill_parent"  
  3.         android:layout_height="fill_parent">  
  4.   
  5.         <button android:layout_height="wrap_content" android:id="@+id/btnRecord"   
  6.                 android:layout_width="fill_parent" android:text="开始边录边放">  
  7.         <button android:layout_height="wrap_content"   
  8.                 android:layout_width="fill_parent" android:text="停止" android:id="@+id/btnStop">  
  9.         <button android:layout_height="wrap_content" android:id="@+id/btnExit"   
  10.                 android:layout_width="fill_parent" android:text="退出">  
  11.         <textview android:id="@+id/TextView01" android:layout_height="wrap_content"   
  12.                 android:text="程序音量调节" android:layout_width="fill_parent">  
  13.         <seekbar android:layout_height="wrap_content" android:id="@+id/skbVolume"   
  14.                 android:layout_width="fill_parent">  

       testRecord.java的源码如下：

Java代码
  1. package com.testRecord;  
  2.   
  3. import android.app.Activity;  
  4. import android.media.AudioFormat;  
  5. import android.media.AudioManager;  
  6. import android.media.AudioRecord;  
  7. import android.media.AudioTrack;  
  8. import android.media.MediaRecorder;  
  9. import android.os.Bundle;  
  10. import android.view.View;  
  11. import android.widget.Button;  
  12. import android.widget.SeekBar;  
  13. import android.widget.Toast;  
  14.   
  15. public class testRecord extends Activity {  
  16.         /** Called when the activity is first created. */  
  17.         Button btnRecord, btnStop, btnExit;  
  18.         SeekBar skbVolume;//调节音量  
  19.         boolean isRecording = false;//是否录放的标记  
  20.         static final int frequency = 44100;  
  21.         static final int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO;  
  22.         static final int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;  
  23.         int recBufSize,playBufSize;  
  24.         AudioRecord audioRecord;  
  25.         AudioTrack audioTrack;  
  26.   
  27.         @Override  
  28.         public void onCreate(Bundle savedInstanceState) {  
  29.                 super.onCreate(savedInstanceState);  
  30.                 setContentView(R.layout.main);  
  31.                 setTitle("助听器");  
  32.                 recBufSize = AudioRecord.getMinBufferSize(frequency,  
  33.                                 channelConfiguration, audioEncoding);  
  34.   
  35.                 playBufSize=AudioTrack.getMinBufferSize(frequency,  
  36.                                 channelConfiguration, audioEncoding);  
  37.                 // -----------------------------------------  
  38.                 audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency,  
  39.                                 channelConfiguration, audioEncoding, recBufSize);  
  40.   
  41.                 audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, frequency,  
  42.                                 channelConfiguration, audioEncoding,  
  43.                                 playBufSize, AudioTrack.MODE_STREAM);  
  44.                 //------------------------------------------  
  45.                 btnRecord = (Button) this.findViewById(R.id.btnRecord);  
  46.                 btnRecord.setOnClickListener(new ClickEvent());  
  47.                 btnStop = (Button) this.findViewById(R.id.btnStop);  
  48.                 btnStop.setOnClickListener(new ClickEvent());  
  49.                 btnExit = (Button) this.findViewById(R.id.btnExit);  
  50.                 btnExit.setOnClickListener(new ClickEvent());  
  51.                 skbVolume=(SeekBar)this.findViewById(R.id.skbVolume);  
  52.                 skbVolume.setMax(100);//音量调节的极限  
  53.                 skbVolume.setProgress(70);//设置seekbar的位置值  
  54.                 audioTrack.setStereoVolume(0.7f, 0.7f);//设置当前音量大小  
  55.                 skbVolume.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {  
  56.                           
  57.                         @Override  
  58.                         public void onStopTrackingTouch(SeekBar seekBar) {  
  59.                                 float vol=(float)(seekBar.getProgress())/(float)(seekBar.getMax());  
  60.                                 audioTrack.setStereoVolume(vol, vol);//设置音量  
  61.                         }  
  62.                           
  63.                         @Override  
  64.                         public void onStartTrackingTouch(SeekBar seekBar) {  
  65.                                 // TODO Auto-generated method stub  
  66.                         }  
  67.                           
  68.                         @Override  
  69.                         public void onProgressChanged(SeekBar seekBar, int progress,  
  70.                                         boolean fromUser) {  
  71.                                 // TODO Auto-generated method stub  
  72.                         }  
  73.                 });  
  74.         }  
  75.   
  76.         @Override  
  77.         protected void onDestroy() {  
  78.                 super.onDestroy();  
  79.                 android.os.Process.killProcess(android.os.Process.myPid());  
  80.         }  
  81.   
  82.         class ClickEvent implements View.OnClickListener {  
  83.   
  84.                 @Override  
  85.                 public void onClick(View v) {  
  86.                         if (v == btnRecord) {  
  87.                                 isRecording = true;  
  88.                                 new RecordPlayThread().start();// 开一条线程边录边放  
  89.                         } else if (v == btnStop) {  
  90.                                 isRecording = false;  
  91.                         } else if (v == btnExit) {  
  92.                                 isRecording = false;  
  93.                                 testRecord.this.finish();  
  94.                         }  
  95.                 }  
  96.         }  
  97.   
  98.         class RecordPlayThread extends Thread {  
  99.                 public void run() {  
  100.                         try {  
  101.                                 byte[] buffer = new byte[recBufSize];  
  102.                                 audioRecord.startRecording();//开始录制  
  103.                                 audioTrack.play();//开始播放  
  104.                                   
  105.                                 while (isRecording) {  
  106.                                         //从MIC保存数据到缓冲区  
  107.                                         int bufferReadResult = audioRecord.read(buffer, 0,  
  108.                                                         recBufSize);  
  109.   
  110.                                         byte[] tmpBuf = new byte[bufferReadResult];  
  111.                                         System.arraycopy(buffer, 0, tmpBuf, 0, bufferReadResult);  
  112.                                         //写入数据即播放  
  113.                                         audioTrack.write(tmpBuf, 0, tmpBuf.length);  
  114.                                 }  
  115.                                 audioTrack.stop();  
  116.                                 audioRecord.stop();  
  117.                         } catch (Throwable t) {  
  118.                                 Toast.makeText(testRecord.this, t.getMessage(), 1000);  
  119.                         }  
  120.                 }  
  121.         };  
  122. }  
本文发布：Android开发网
本文地址：http://www.jizhuomi.com/android/course/464.html
2015年8月10日
发布:鸡啄米 分类:Android开发教程 浏览: 评论:0