Android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sdcard
        if(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sdcard
        if(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22050，16000，11025
    public 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;
        else
            return 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amr
    private Button btn_record_wav;
    private Button btn_record_amr;
    private Button btn_stop;
    private TextView txt;
    private UIHandler uiHandler;
    private UIThread uiThread; 

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewByIds();
        setListeners();
        init();
    } 

    @Override
    public 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UI
            return;
        }
        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() {
        }
        @Override
        public void handleMessage(Message msg) {
            // TODO Auto-generated method stub
            Log.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 block
                    e.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
            } 

        }
    } 

}
作者：风倾清凌
出处：http://www.cnblogs.com/Amandaliu/