Android之录音--AudioRecord、MediaRecorder

Android提供了两个API用于实现录音功能：android.media.AudioRecord、android.media.MediaRecorder。

网上有很多谈论这两个类的资料。现在大致总结下：

1、AudioRecord

主要是实现边录边播（AudioRecord+AudioTrack）以及对音频的实时处理（如会说话的汤姆猫、语音）

优点：语音的实时处理，可以用代码实现各种音频的封装

缺点：输出是PCM语音数据，如果保存成音频文件，是不能够被播放器播放的，所以必须先写代码实现数据编码以及压缩

示例：

使用AudioRecord类录音，并实现WAV格式封装。录音20s，输出的音频文件大概为3.5M左右（已写测试代码）

2、MediaRecorder

已经集成了录音、编码、压缩等，支持少量的录音音频格式，大概有.aac（API = 16） .amr .3gp

优点：大部分以及集成，直接调用相关接口即可，代码量小

缺点：无法实时处理音频；输出的音频格式不是很多，例如没有输出mp3格式文件

示例：

使用MediaRecorder类录音，输出amr格式文件。录音20s，输出的音频文件大概为33K（已写测试代码）

3、音频格式比较

WAV格式：录音质量高，但是压缩率小，文件大

AAC格式：相对于mp3，AAC格式的音质更佳，文件更小；有损压缩；一般苹果或者Android SDK4.1.2（API 16）及以上版本支持播放

AMR格式：压缩比比较大，但相对其他的压缩格式质量比较差，多用于人声，通话录音

至于常用的mp3格式，使用MediaRecorder没有该视频格式输出。一些人的做法是使用AudioRecord录音，然后编码成wav格式，再转换成mp3格式

再贴上一些测试工程。

功能描述：

1、点击“录音WAV文件”，开始录音。录音完成后，生成文件/sdcard/FinalAudio.wav

2、点击“录音AMR文件”，开始录音。录音完成后，生成文件/sdcard/FinalAudio.amr

3、点击“停止录音”，停止录音，并显示录音输出文件以及该文件大小。

大致代码如下：

1、AudioRecord录音，封装成WAV格式

package com.example.audiorecordtest;import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;import android.media.AudioFormat;
import android.media.AudioRecord;public class AudioRecordFunc { // 缓冲区字节大小  private int bufferSizeInBytes = 0;//AudioName裸音频数据文件 ，麦克风private String AudioName = "";  //NewAudioName可播放的音频文件  private String NewAudioName = "";private AudioRecord audioRecord;  private boolean isRecord = false;// 设置正在录制的状态  private static AudioRecordFunc mInstance; private AudioRecordFunc(){}   public synchronized static AudioRecordFunc getInstance(){if(mInstance == null) mInstance = new AudioRecordFunc(); return mInstance; }public int startRecordAndFile() {//判断是否有外部存储设备sdcardif(AudioFileFunc.isSdcardExit()){if(isRecord){return ErrorCode.E_STATE_RECODING;}else{if(audioRecord == null)creatAudioRecord();audioRecord.startRecording();  // 让录制状态为true  isRecord = true;  // 开启音频文件写入线程  new Thread(new AudioRecordThread()).start();  return ErrorCode.SUCCESS;}}       else{return ErrorCode.E_NOSDCARD;            }       }  public void stopRecordAndFile() {  close();  }public long getRecordFileSize(){return AudioFileFunc.getFileSize(NewAudioName);}private void close() {  if (audioRecord != null) {  System.out.println("stopRecord");  isRecord = false;//停止文件写入  audioRecord.stop();  audioRecord.release();//释放资源  audioRecord = null;  }  }private void creatAudioRecord() {  // 获取音频文件路径AudioName = AudioFileFunc.getRawFilePath();NewAudioName = AudioFileFunc.getWavFilePath(); // 获得缓冲区字节大小  bufferSizeInBytes = AudioRecord.getMinBufferSize(AudioFileFunc.AUDIO_SAMPLE_RATE,  AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT);  // 创建AudioRecord对象  audioRecord = new AudioRecord(AudioFileFunc.AUDIO_INPUT, AudioFileFunc.AUDIO_SAMPLE_RATE,  AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT, bufferSizeInBytes);  }class AudioRecordThread implements Runnable {  @Override public void run() {  writeDateTOFile();//往文件中写入裸数据  copyWaveFile(AudioName, NewAudioName);//给裸数据加上头文件  }  }  /** * 这里将数据写入文件，但是并不能播放，因为AudioRecord获得的音频是原始的裸音频， * 如果需要播放就必须加入一些格式或者编码的头信息。但是这样的好处就是你可以对音频的 裸数据进行处理，比如你要做一个爱说话的TOM * 猫在这里就进行音频的处理，然后重新封装 所以说这样得到的音频比较容易做一些音频的处理。 */ private void writeDateTOFile() {  // new一个byte数组用来存一些字节数据，大小为缓冲区大小  byte[] audiodata = new byte[bufferSizeInBytes];  FileOutputStream fos = null;  int readsize = 0;  try {  File file = new File(AudioName);  if (file.exists()) {  file.delete();  }  fos = new FileOutputStream(file);// 建立一个可存取字节的文件  } catch (Exception e) {  e.printStackTrace();  }  while (isRecord == true) {  readsize = audioRecord.read(audiodata, 0, bufferSizeInBytes);  if (AudioRecord.ERROR_INVALID_OPERATION != readsize && fos!=null) {  try {  fos.write(audiodata);  } catch (IOException e) {  e.printStackTrace();  }  }  }  try {if(fos != null)fos.close();// 关闭写入流  } catch (IOException e) {  e.printStackTrace();  }  }  // 这里得到可播放的音频文件  private void copyWaveFile(String inFilename, String outFilename) {  FileInputStream in = null;  FileOutputStream out = null;  long totalAudioLen = 0;  long totalDataLen = totalAudioLen + 36;  long longSampleRate = AudioFileFunc.AUDIO_SAMPLE_RATE;  int channels = 2;  long byteRate = 16 * AudioFileFunc.AUDIO_SAMPLE_RATE * channels / 8;  byte[] data = new byte[bufferSizeInBytes];  try {  in = new FileInputStream(inFilename);  out = new FileOutputStream(outFilename);  totalAudioLen = in.getChannel().size();  totalDataLen = totalAudioLen + 36;  WriteWaveFileHeader(out, totalAudioLen, totalDataLen,  longSampleRate, channels, byteRate);  while (in.read(data) != -1) {  out.write(data);  }  in.close();  out.close();  } catch (FileNotFoundException e) {  e.printStackTrace();  } catch (IOException e) {  e.printStackTrace();  }  }  /** * 这里提供一个头信息。插入这些信息就可以得到可以播放的文件。 * 为我为啥插入这44个字节，这个还真没深入研究，不过你随便打开一个wav * 音频的文件，可以发现前面的头文件可以说基本一样哦。每种格式的文件都有 * 自己特有的头文件。 */ private void WriteWaveFileHeader(FileOutputStream out, long totalAudioLen,  long totalDataLen, long longSampleRate, int channels, long byteRate)  throws IOException {  byte[] header = new byte[44];  header[0] = 'R'; // RIFF/WAVE header  header[1] = 'I';  header[2] = 'F';  header[3] = 'F';  header[4] = (byte) (totalDataLen & 0xff);  header[5] = (byte) ((totalDataLen >> 8) & 0xff);  header[6] = (byte) ((totalDataLen >> 16) & 0xff);  header[7] = (byte) ((totalDataLen >> 24) & 0xff);  header[8] = 'W';  header[9] = 'A';  header[10] = 'V';  header[11] = 'E';  header[12] = 'f'; // 'fmt ' chunk  header[13] = 'm';  header[14] = 't';  header[15] = ' ';  header[16] = 16; // 4 bytes: size of 'fmt ' chunk  header[17] = 0;  header[18] = 0;  header[19] = 0;  header[20] = 1; // format = 1  header[21] = 0;  header[22] = (byte) channels;  header[23] = 0;  header[24] = (byte) (longSampleRate & 0xff);  header[25] = (byte) ((longSampleRate >> 8) & 0xff);  header[26] = (byte) ((longSampleRate >> 16) & 0xff);  header[27] = (byte) ((longSampleRate >> 24) & 0xff);  header[28] = (byte) (byteRate & 0xff);  header[29] = (byte) ((byteRate >> 8) & 0xff);  header[30] = (byte) ((byteRate >> 16) & 0xff);  header[31] = (byte) ((byteRate >> 24) & 0xff);  header[32] = (byte) (2 * 16 / 8); // block align  header[33] = 0;  header[34] = 16; // bits per sample  header[35] = 0;  header[36] = 'd';  header[37] = 'a';  header[38] = 't';  header[39] = 'a';  header[40] = (byte) (totalAudioLen & 0xff);  header[41] = (byte) ((totalAudioLen >> 8) & 0xff);  header[42] = (byte) ((totalAudioLen >> 16) & 0xff);  header[43] = (byte) ((totalAudioLen >> 24) & 0xff);  out.write(header, 0, 44);  }  
}

2、MediaRecorder录音，输出amr格式音频

package com.example.audiorecordtest;import java.io.File;
import java.io.IOException;import android.media.MediaRecorder;public class MediaRecordFunc {  private boolean isRecord = false;private MediaRecorder mMediaRecorder;private MediaRecordFunc(){}private static MediaRecordFunc mInstance;public synchronized static MediaRecordFunc getInstance(){if(mInstance == null)mInstance = new MediaRecordFunc();return mInstance;}public int startRecordAndFile(){//判断是否有外部存储设备sdcardif(AudioFileFunc.isSdcardExit()){if(isRecord){return ErrorCode.E_STATE_RECODING;}else{if(mMediaRecorder == null)createMediaRecord();try{mMediaRecorder.prepare();mMediaRecorder.start();// 让录制状态为true  isRecord = true;return ErrorCode.SUCCESS;}catch(IOException ex){ex.printStackTrace();return ErrorCode.E_UNKOWN;}}}       else{return ErrorCode.E_NOSDCARD;            }       }public void stopRecordAndFile(){close();}public long getRecordFileSize(){return AudioFileFunc.getFileSize(AudioFileFunc.getAMRFilePath());}private void createMediaRecord(){/* ①Initial：实例化MediaRecorder对象 */mMediaRecorder = new MediaRecorder();/* setAudioSource/setVedioSource*/mMediaRecorder.setAudioSource(AudioFileFunc.AUDIO_INPUT);//设置麦克风/* 设置输出文件的格式：THREE_GPP/MPEG-4/RAW_AMR/Default* THREE_GPP(3gp格式，H263视频/ARM音频编码)、MPEG-4、RAW_AMR(只支持音频且音频编码要求为AMR_NB)*/mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);/* 设置音频文件的编码：AAC/AMR_NB/AMR_MB/Default */mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);/* 设置输出文件的路径 */File file = new File(AudioFileFunc.getAMRFilePath());if (file.exists()) {  file.delete();  } mMediaRecorder.setOutputFile(AudioFileFunc.getAMRFilePath());}private void close(){if (mMediaRecorder != null) {  System.out.println("stopRecord");  isRecord = false;mMediaRecorder.stop();  mMediaRecorder.release();  mMediaRecorder = null;}  }
}

3、其他文件

AudioFileFunc.java

package com.example.audiorecordtest;import java.io.File;import android.media.MediaRecorder;
import android.os.Environment;public class AudioFileFunc {//音频输入-麦克风public final static int AUDIO_INPUT = MediaRecorder.AudioSource.MIC;//采用频率//44100是目前的标准，但是某些设备仍然支持22050，16000，11025public final static int AUDIO_SAMPLE_RATE = 44100;  //44.1KHz,普遍使用的频率   //录音输出文件private final static String AUDIO_RAW_FILENAME = "RawAudio.raw";private final static String AUDIO_WAV_FILENAME = "FinalAudio.wav";public final static String AUDIO_AMR_FILENAME = "FinalAudio.amr";/*** 判断是否有外部存储设备sdcard* @return true | false*/public static boolean isSdcardExit(){       if (Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))return true;elsereturn false;}/*** 获取麦克风输入的原始音频流文件路径* @return*/public static String getRawFilePath(){String mAudioRawPath = "";if(isSdcardExit()){String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();mAudioRawPath = fileBasePath+"/"+AUDIO_RAW_FILENAME;}   return mAudioRawPath;}/*** 获取编码后的WAV格式音频文件路径* @return*/public static String getWavFilePath(){String mAudioWavPath = "";if(isSdcardExit()){String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();mAudioWavPath = fileBasePath+"/"+AUDIO_WAV_FILENAME;}return mAudioWavPath;}/*** 获取编码后的AMR格式音频文件路径* @return*/public static String getAMRFilePath(){String mAudioAMRPath = "";if(isSdcardExit()){String fileBasePath = Environment.getExternalStorageDirectory().getAbsolutePath();mAudioAMRPath = fileBasePath+"/"+AUDIO_AMR_FILENAME;}return mAudioAMRPath;}   /*** 获取文件大小* @param path,文件的绝对路径* @return*/public static long getFileSize(String path){File mFile = new File(path);if(!mFile.exists())return -1;return mFile.length();}}

4、其他文件

ErrorCode.java

package com.example.audiorecordtest;import android.content.Context;
import android.content.res.Resources.NotFoundException;public class ErrorCode {public final static int SUCCESS = 1000;public final static int E_NOSDCARD = 1001;public final static int E_STATE_RECODING = 1002;public final static int E_UNKOWN = 1003;public static String getErrorInfo(Context vContext, int vType) throws NotFoundException{switch(vType){case SUCCESS:return "success";case E_NOSDCARD:return vContext.getResources().getString(R.string.error_no_sdcard);case E_STATE_RECODING:return vContext.getResources().getString(R.string.error_state_record);  case E_UNKOWN:default:return vContext.getResources().getString(R.string.error_unknown);           }}}

5、string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources><string name="app_name">AudioRecordTest</string><string name="hello_world">测试AudioRecord，实现录音功能</string><string name="menu_settings">Settings</string><string name="view_record_wav">录音WAV文件</string><string name="view_record_amr">录音AMR文件</string><string name="view_stop">停止录音</string><string name="error_no_sdcard">没有SD卡，无法存储录音数据</string><string name="error_state_record">正在录音中，请先停止录音</string><string name="error_unknown">无法识别的错误</string></resources>

6、主程序MainActivity

package com.example.audiorecordtest; import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView; public class MainActivity extends Activity {private final static int FLAG_WAV = 0;private final static int FLAG_AMR = 1;private int mState = -1;    //-1:没再录制，0：录制wav，1：录制amrprivate Button btn_record_wav;private Button btn_record_amr;private Button btn_stop;private TextView txt;private UIHandler uiHandler;private UIThread uiThread; @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);findViewByIds();setListeners();init();} @Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.activity_main, menu);return true;}private void findViewByIds(){btn_record_wav = (Button)this.findViewById(R.id.btn_record_wav);btn_record_amr = (Button)this.findViewById(R.id.btn_record_amr);btn_stop = (Button)this.findViewById(R.id.btn_stop);txt = (TextView)this.findViewById(R.id.text);}private void setListeners(){btn_record_wav.setOnClickListener(btn_record_wav_clickListener);btn_record_amr.setOnClickListener(btn_record_amr_clickListener);btn_stop.setOnClickListener(btn_stop_clickListener);}private void init(){uiHandler = new UIHandler();        }private Button.OnClickListener btn_record_wav_clickListener = new Button.OnClickListener(){public void onClick(View v){record(FLAG_WAV);}};private Button.OnClickListener btn_record_amr_clickListener = new Button.OnClickListener(){public void onClick(View v){record(FLAG_AMR);}};private Button.OnClickListener btn_stop_clickListener = new Button.OnClickListener(){public void onClick(View v){stop();     }};/*** 开始录音* @param mFlag，0：录制wav格式，1：录音amr格式*/private void record(int mFlag){if(mState != -1){Message msg = new Message();Bundle b = new Bundle();// 存放数据b.putInt("cmd",CMD_RECORDFAIL);b.putInt("msg", ErrorCode.E_STATE_RECODING);msg.setData(b); uiHandler.sendMessage(msg); // 向Handler发送消息,更新UIreturn;} int mResult = -1;switch(mFlag){        case FLAG_WAV:AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance();mResult = mRecord_1.startRecordAndFile();            break;case FLAG_AMR:MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();mResult = mRecord_2.startRecordAndFile();break;}if(mResult == ErrorCode.SUCCESS){uiThread = new UIThread();new Thread(uiThread).start();mState = mFlag;}else{Message msg = new Message();Bundle b = new Bundle();// 存放数据b.putInt("cmd",CMD_RECORDFAIL);b.putInt("msg", mResult);msg.setData(b); uiHandler.sendMessage(msg); // 向Handler发送消息,更新UI}}/*** 停止录音*/private void stop(){if(mState != -1){switch(mState){case FLAG_WAV:AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance();mRecord_1.stopRecordAndFile();break;case FLAG_AMR:MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();mRecord_2.stopRecordAndFile();break;}            if(uiThread != null){uiThread.stopThread();}if(uiHandler != null)uiHandler.removeCallbacks(uiThread); Message msg = new Message();Bundle b = new Bundle();// 存放数据b.putInt("cmd",CMD_STOP);b.putInt("msg", mState);msg.setData(b);uiHandler.sendMessageDelayed(msg,1000); // 向Handler发送消息,更新UI mState = -1;}}    private final static int CMD_RECORDING_TIME = 2000;private final static int CMD_RECORDFAIL = 2001;private final static int CMD_STOP = 2002;class UIHandler extends Handler{public UIHandler() {}@Overridepublic void handleMessage(Message msg) {// TODO Auto-generated method stubLog.d("MyHandler", "handleMessage......");super.handleMessage(msg);Bundle b = msg.getData();int vCmd = b.getInt("cmd");switch(vCmd){case CMD_RECORDING_TIME:int vTime = b.getInt("msg");MainActivity.this.txt.setText("正在录音中，已录制："+vTime+" s");break;case CMD_RECORDFAIL:int vErrorCode = b.getInt("msg");String vMsg = ErrorCode.getErrorInfo(MainActivity.this, vErrorCode);MainActivity.this.txt.setText("录音失败："+vMsg);break;case CMD_STOP:                int vFileType = b.getInt("msg");switch(vFileType){case FLAG_WAV:AudioRecordFunc mRecord_1 = AudioRecordFunc.getInstance(); long mSize = mRecord_1.getRecordFileSize();MainActivity.this.txt.setText("录音已停止.录音文件:"+AudioFileFunc.getWavFilePath()+"\n文件大小："+mSize);break;case FLAG_AMR:                    MediaRecordFunc mRecord_2 = MediaRecordFunc.getInstance();mSize = mRecord_2.getRecordFileSize();MainActivity.this.txt.setText("录音已停止.录音文件:"+AudioFileFunc.getAMRFilePath()+"\n文件大小："+mSize);break;}break;default:break;}}};class UIThread implements Runnable {        int mTimeMill = 0;boolean vRun = true;public void stopThread(){vRun = false;}public void run() {while(vRun){try {Thread.sleep(1000);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}mTimeMill ++;Log.d("thread", "mThread........"+mTimeMill);Message msg = new Message();Bundle b = new Bundle();// 存放数据b.putInt("cmd",CMD_RECORDING_TIME);b.putInt("msg", mTimeMill);msg.setData(b); MainActivity.this.uiHandler.sendMessage(msg); // 向Handler发送消息,更新UI} }} }