編輯:Android開發實例
Android可以通過MediaRecorder和AudioRecord這兩個工具來實現錄音,MediaRecorder直接把麥克風的數據存到文件,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序。
PS:由於目前的Android模擬器還不支持AudioRecord,因此本程序需要編譯之後放到真機運行。
先貼出本文程序運行截圖:
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="程序音量調節" 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);//音量調節的極限
- skbVolume.setProgress(70);//設置seekbar的位置值
- audioTrack.setStereoVolume(0.7f, 0.7f);//設置當前音量大小
- skbVolume.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
- @Override
- public void onStopTrackingTouch(SeekBar seekBar) {
- float vol=(float)(seekBar.getProgress())/(float)(seekBar.getMax());
- audioTrack.setStereoVolume(vol, vol);//設置音量
- }
- @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();//開始錄制
- audioTrack.play();//開始播放
- while (isRecording) {
- //從MIC保存數據到緩沖區
- int bufferReadResult = audioRecord.read(buffer, 0,
- recBufSize);
- byte[] tmpBuf = new byte[bufferReadResult];
- System.arraycopy(buffer, 0, tmpBuf, 0, bufferReadResult);
- //寫入數據即播放
- audioTrack.write(tmpBuf, 0, tmpBuf.length);
- }
- audioTrack.stop();
- audioRecord.stop();
- } catch (Throwable t) {
- Toast.makeText(testRecord.this, t.getMessage(), 1000);
- }
- }
- };
- }
PS:程序音量調節只是程序內部調節音量而已,要調到最大音量還需要手動設置系統音量。
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