录音器 AudioRecorder

实现录音器有两种方式可以选择：

1.AudioRecord(基于字节流录音)
优点：可以实现语音的实时处理，进行边录边播，对音频的实时处理。
缺点：输出的是PCM的语音数据，如果保存成音频文件是不能被播放器播放的。要用到AudioTrack这个去进行处理。

2.MediaRecorder(基于文件录音)
已集成了录音，编码，压缩等，支持少量的音频格式文件。
优点：封装度很高，操作简单
缺点：无法实现实时处理音频，输出的音频格式少。

权限：

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

AudioRecorder录音工具类代码如下：

package com.example.m_evolution.Utils;

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

public class AudioRecoderUtils {

    //文件路径
    private String filePath;
    //文件夹路径
    private String FolderPath;

    //录音的线程
    private Thread mThread;

//    private MediaRecorder mMediaRecorder;
    private AudioRecord audioRecord;
    private boolean isRecording;
    private int channelConfiguration = AudioFormat.CHANNEL_IN_MONO;
    private int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
    private int sampleRate = 44100;
    private int bufferSizeInBytes;

    private final String TAG = "fan";
    public static final int MAX_LENGTH = 1000 * 60 * 10;// 最大录音时长1000*60*10;

    private OnAudioStatusUpdateListener audioStatusUpdateListener;

    /**
     * 文件存储默认sdcard/record
     */
    public AudioRecoderUtils(){

        //默认保存路径为/sdcard/record/下
        FolderPath = Environment.getExternalStorageDirectory()+"/record/";
        bufferSizeInBytes = AudioRecord.getMinBufferSize(sampleRate,
                channelConfiguration, audioEncoding); // need to be larger than size of a frame

        audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,
                sampleRate, channelConfiguration, audioEncoding,
                bufferSizeInBytes); //麦克风
    }

    public void startRecord(){
        mThread = new Thread(new Runnable() {
            @Override
            public void run() {
                /* 获取开始时间* */
                startTime = System.currentTimeMillis();
                //设置录制指标
                isRecording = true;
                //自动更新界面
                updateMicStatus();
                //设置存储路径
                filePath = FolderPath+getCurrentDate("yyyyMMddHHmmss") + ".wav";
                File recordingFile = new File(filePath);
                OutputStream out = null;
                ByteArrayOutputStream baos = null;
                try {
                    baos = new ByteArrayOutputStream();
                    audioRecord.startRecording();
                    byte[] buffer = new byte[bufferSizeInBytes];
                    int bufferReadResult = 0;
                    while (isRecording) {
                        bufferReadResult = audioRecord.read(buffer, 0,
                                bufferSizeInBytes);
                        if(bufferReadResult>0){
                            baos.write(buffer, 0, bufferReadResult);
                        }
                    }
                    Log.i(TAG, "stop recording,file=" + recordingFile.getAbsolutePath());
                    buffer = baos.toByteArray();
                    Log.i(TAG, "audio byte len="+buffer.length);
                    out = new FileOutputStream(recordingFile);
                    out.write(getWavHeader(buffer.length));
                    out.write(buffer);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    if (out != null) {
                        try {
                            out.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if(baos!=null){
                        try {
                            baos.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        });
        mThread.start();
    }

    public void stopRecord(){
        stopRecording();
        audioStatusUpdateListener.onStop(filePath);
        filePath = "";
    }

    public byte[] getWavHeader(long totalAudioLen){
        int mChannels = 1;
        long totalDataLen = totalAudioLen + 36;
        long longSampleRate = sampleRate;
        long byteRate = sampleRate * 2 * mChannels;

        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) mChannels;
        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 * mChannels);  // 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);

        return header;
    }

    private long startTime;
    private long endTime;

    public static String getCurrentDate(String pattern) {
        SimpleDateFormat formatter = new SimpleDateFormat(pattern);
        Date curDate = new Date(System.currentTimeMillis());// 获取当前时间
        String timestamp = formatter.format(curDate);
        return timestamp;
    }

    public void stopRecording() {
        try {
            isRecording = false;
            audioRecord.stop();
            audioRecord.release();
            audioRecord = null;
            audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,
                    sampleRate, channelConfiguration, audioEncoding,
                    bufferSizeInBytes); //麦克风
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private final Handler mHandler = new Handler();
    private Runnable mUpdateMicStatusTimer = new Runnable() {
        public void run() {
            updateMicStatus();
        }
    };

    private int SPACE = 100;//显示时间的间隔时间

    public void setOnAudioStatusUpdateListener(OnAudioStatusUpdateListener audioStatusUpdateListener) {
        this.audioStatusUpdateListener = audioStatusUpdateListener;
    }

    /**
     * 更新麦克状态
     */
    private void updateMicStatus() {

        if (isRecording) {
            if(null != audioStatusUpdateListener) {
                audioStatusUpdateListener.onUpdate(System.currentTimeMillis()-startTime);
            }
            mHandler.postDelayed(mUpdateMicStatusTimer, SPACE);
        }
    }

    public interface OnAudioStatusUpdateListener {
        /**
         * 录音中...
         * @param db 当前声音分贝
         * @param time 录音时长
         */
        public void onUpdate(long time);

        /**
         * 停止录音
         * @param filePath 保存路径
         */
        public void onStop(String filePath);
    }

}