我們通常可以通過以下步驟在Android中錄製音頻或視頻
(1) 創建android.media.MediaRecorder的一個實例。
(2) 創建android.content.ContentValues的一個實例,並添加TITLE、TIMESTAMP及重要的MIME_TYPE等屬性。
(3) 使用android.content.ContentResolver爲數據創建一個目標文件路徑。
(4) 要在視圖界面上設置預覽顯示,可以使用MediaRecorder.setPreviewDisplay()方法。
(5) 使用MediaRecorder.setAudioSource()設置音頻來源。
(6) 使用MediaRecorder.setOutputFormat()設置輸出文件格式。
(7) 使用MediaRecorder.setAudioEncoder()設置音頻編碼。
(8) 使用prepare()和start()準備和開始錄製。
(9) 使用stop()和release()正常停止和清除錄製過程。
代碼如下:
------------------------RecordingActivity--------------------------
package cn.com.pan;
import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Intent;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.MediaStore.MediaColumns;
import android.util.Log;
import android.view.View;
import android.widget.Button;
public class RecordingActivity extends Activity {
MediaRecorder mRecorder;
File mSampleFile = null;
static final String SAMPLE_PREFIX ="recording";
static final String SAMPLE_EXTENSION =".mp3";
private static final String TAG ="RecordingActivity";
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.mRecorder = newMediaRecorder();
Button startRecording =(Button) this.findViewById(R.id.startRecording);
Button stopRecording = (Button)this.findViewById(R.id.stopRecording);
startRecording.setOnClickListener(newView.OnClickListener() {
@Override
public voidonClick(View v) {
//TODO Auto-generated method stub
startRecording();
}
});
stopRecording.setOnClickListener(newView.OnClickListener() {
@Override
public voidonClick(View v) {
//TODO Auto-generated method stub
stopRecording();
addToDB();
}
});
}
protected void addToDB() {
ContentValues values = newContentValues(3);
long current =System.currentTimeMillis();
values.put(MediaColumns.TITLE,"test_audio");
values.put(MediaColumns.DATE_ADDED,(int) (current / 1000));
values.put(MediaColumns.MIME_TYPE,"audio/mp3");
values.put(MediaColumns.DATA,mSampleFile.getAbsolutePath());
ContentResolver contentResolver= getContentResolver();
Uri base =MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Uri newUri =contentResolver.insert(base, values);
sendBroadcast(newIntent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri));
}
protected void startRecording() {
this.mRecorder = newMediaRecorder();
this.mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
this.mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
this.mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
this.mRecorder.setOutputFile(this.mSampleFile.getAbsolutePath());
try {
this.mRecorder.prepare();
} catch (IllegalStateExceptione1) {
// TODOAuto-generated catch block
e1.printStackTrace();
} catch (IOException e1){
// TODOAuto-generated catch block
e1.printStackTrace();
}
this.mRecorder.start();
if (this.mSampleFile == null){
FilesampleDir = Environment.getExternalStorageDirectory();
try {
this.mSampleFile= File.createTempFile(
RecordingActivity.SAMPLE_PREFIX,
RecordingActivity.SAMPLE_EXTENSION,sampleDir);
} catch(IOException e) {
//TODO Auto-generated catch block
Log.e(TAG,"sdcard access error");
return;
}
}
}
protected void stopRecording() {
this.mRecorder.stop();
this.mRecorder.release();
}
}
--------------------------------main.xml-------------------------------------
<?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">
<Buttonandroid:id="@+id/startRecording"android:layout_width="fill_parent"
android:layout_height="wrap_content"android:text="start"></Button>
<Buttonandroid:id="@+id/stopRecording"android:layout_width="fill_parent"
android:layout_height="wrap_content"android:text="stop"></Button>
</LinearLayout>
---------------------------------AndroidManifest.xml---------------------------
<?xml version="1.0"encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="cn.com.pan" android:versionCode="1"android:versionName="1.0">
<applicationandroid:icon="@drawable/icon"android:label="@string/app_name">
<activityandroid:name=".RecordingActivity"android:label="@string/app_name">
<intent-filter>
<actionandroid:name="android.intent.action.MAIN" />
<categoryandroid:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
<uses-permissionandroid:name="android.permission.RECORD_AUDIO"></uses-permission>
<uses-sdkandroid:minSdkVersion="3" />
</manifest>
如果在計算機的音頻系統中播放音樂,AndroidEmulator將選取該音樂並直接錄製到音頻緩衝區中(並不是從麥克風進行實際錄製)。然後可以輕鬆測試該音頻文件,方法是打開AndroidMusic Player並選擇Playlist>RecentlyAdded。播放器就會播放剛錄製的音頻文件了。