Android提高之AudioRecord實現助聽器的方法_Android

通常來說，在進行Android項目開發的時候可以通過MediaRecorder和AudioRecord這兩個工具來實現錄音的功能，MediaRecorder直接把麥克風的資料存到檔案，並且能夠直接進行編碼(如AMR,MP3等)，而AudioRecord則是讀取麥克風的音頻流。本文使用AudioRecord讀取音頻流，使用AudioTrack播放音頻流，通過“邊讀邊播放”以及增大音量的方式來實現一個簡單的助聽器程式。

此處需要注意：由於目前的Android模擬器還不支援AudioRecord，因此本程式需要編譯之後放到真機運行。

先貼出本文程式運行截圖：

另外還要注意：在本程式音量大小只是程式內部調節音量而已，要調到最大音量還需要手動設定系統音量。

使用AudioRecord必須要申請許可，在AndroidManifest.xml裡面添加這句：

<uses-permission android:name="android.permission.RECORD_AUDIO"></uses-permission>

main.xml的源碼如下：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Button android:layout_height="wrap_content" android:id="@+id/btnRecord" android:layout_width="fill_parent" android:text="開始邊錄邊放"></Button> <Button android:layout_height="wrap_content" android:layout_width="fill_parent" android:text="停止" android:id="@+id/btnStop"></Button> <Button android:layout_height="wrap_content" android:id="@+id/btnExit" android:layout_width="fill_parent" android:text="退出"></Button> <TextView android:id="@+id/TextView01" android:layout_height="wrap_content" android:text="程式音量大小" android:layout_width="fill_parent"></TextView> <SeekBar android:layout_height="wrap_content" android:id="@+id/skbVolume" android:layout_width="fill_parent"></SeekBar></LinearLayout>

testRecord.java的源碼如下：

package com.testRecord;import android.app.Activity;import android.media.AudioFormat;import android.media.AudioManager;import android.media.AudioRecord;import android.media.AudioTrack;import android.media.MediaRecorder;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.SeekBar;import android.widget.Toast;public class testRecord extends Activity { /** Called when the activity is first created. */ Button btnRecord, btnStop, btnExit; SeekBar skbVolume;//調節音量 boolean isRecording = false;//是否錄放的標記 static final int frequency = 44100; static final int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO; static final int audioEncoding = AudioFormat.ENCODING_PCM_16BIT; int recBufSize,playBufSize; AudioRecord audioRecord; AudioTrack audioTrack; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); setTitle("助聽器"); recBufSize = AudioRecord.getMinBufferSize(frequency,  channelConfiguration, audioEncoding); playBufSize=AudioTrack.getMinBufferSize(frequency,  channelConfiguration, audioEncoding); // ----------------------------------------- audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency,  channelConfiguration, audioEncoding, recBufSize); audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, frequency,  channelConfiguration, audioEncoding,  playBufSize, AudioTrack.MODE_STREAM); //------------------------------------------ btnRecord = (Button) this.findViewById(R.id.btnRecord); btnRecord.setOnClickListener(new ClickEvent()); btnStop = (Button) this.findViewById(R.id.btnStop); btnStop.setOnClickListener(new ClickEvent()); btnExit = (Button) this.findViewById(R.id.btnExit); btnExit.setOnClickListener(new ClickEvent()); skbVolume=(SeekBar)this.findViewById(R.id.skbVolume); skbVolume.setMax(100);//音量大小的極限 skbVolume.setProgress(70);//設定seekbar的位置值 audioTrack.setStereoVolume(0.7f, 0.7f);//設定當前音量大小 skbVolume.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {  @Override  public void onStopTrackingTouch(SeekBar seekBar) {  float vol=(float)(seekBar.getProgress())/(float)(seekBar.getMax());  audioTrack.setStereoVolume(vol, vol);//設定音量  }    @Override  public void onStartTrackingTouch(SeekBar seekBar) {  // TODO Auto-generated method stub  }    @Override  public void onProgressChanged(SeekBar seekBar, int progress,   boolean fromUser) {  // TODO Auto-generated method stub  } }); } @Override protected void onDestroy() { super.onDestroy(); android.os.Process.killProcess(android.os.Process.myPid()); } class ClickEvent implements View.OnClickListener { @Override public void onClick(View v) {  if (v == btnRecord) {  isRecording = true;  new RecordPlayThread().start();// 開一條線程邊錄邊放  } else if (v == btnStop) {  isRecording = false;  } else if (v == btnExit) {  isRecording = false;  testRecord.this.finish();  } } } class RecordPlayThread extends Thread { public void run() {  try {  byte[] buffer = new byte[recBufSize];  audioRecord.startRecording();//開始錄製  audioTrack.play();//開始播放  while (isRecording) {   //從MIC儲存資料到緩衝區   int bufferReadResult = audioRecord.read(buffer, 0,    recBufSize);   byte[] tmpBuf = new byte[bufferReadResult];   System.arraycopy(buffer, 0, tmpBuf, 0, bufferReadResult);   //寫入資料即播放   audioTrack.write(tmpBuf, 0, tmpBuf.length);  }  audioTrack.stop();  audioRecord.stop();  } catch (Throwable t) {  Toast.makeText(testRecord.this, t.getMessage(), 1000);  } } };}

希望本文所述執行個體對大家的Android項目開發有一定的借鑒價值。