前面一篇介绍了《Android下使用 AudioRecord 和 AudioTrack 实现音频 PCM 数据的采集和播放》,这一篇介绍怎么将采集到的音频数据保存到PCM和wav文件中。其实保存PCM数据不难，只要直接写入文件即可，而保存数据至wav文件只需要将wav文件格式头补上即可。
1、MainActivity.java文件
package com.example.tongjiangsong.audiorecordtrackdemo;
import android.os.Bundle;
import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity implements View.OnClickListener {
PipedInputStream in;
boolean isRecord;
MAudioRecord m_audio_record ;
Button record_btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
isRecord = false;
record_btn = (Button)findViewById(R.id.button);
record_btn.setOnClickListener(this);
}
private void startRecord(){
in = new PipedInputStream();
new Thread(new Runnable() {
@Override
public void run() {
try {
m_audio_record = new MAudioRecord(MainActivity.this, in);
m_audio_record.StartAudioData();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
@Override
public void onClick(View view) {
if (isRecord){
isRecord = false;
m_audio_record.stopRecord();
m_audio_player.stopPlay();
}else{
isRecord = true;
startRecord();
}
}
}
2、MAudioRecord.java文件
package com.example.tongjiangsong.audiorecordtrackdemo;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import android.content.Context;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Environment;
import android.util.Log;
import static android.content.ContentValues.TAG;
/*
* To getaudio or play audio
* */
public class MAudioRecord {
private AudioRecord audioRecord;
private Context context;
private boolean isRecording = false ;
private int buffersize = 0;
private PipedOutputStream outstream ;//利用管道传输数据
public MAudioRecord(Context context , PipedInputStream instream) throws IOException {
this.context = context;
//初始化管道流 用于向外传输数据
outstream = new PipedOutputStream();
outstream.connect(instream);
}
public void StartAudioData(){//得到录音数据
int frequency = 11025;
int channelConfiguration = AudioFormat.CHANNEL_IN_STEREO;
int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
buffersize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding);
audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency, channelConfiguration, audioEncoding, buffersize);
byte[] buffer = new byte[1024];
audioRecord.startRecording();//开始录音
isRecording = true;
int bufferReadSize = 1024;
String tmpName = System.currentTimeMillis()+"_"+44100+"";
final File tmpFile = createFile(tmpName+".pcm");
final File tmpOutFile = createFile(tmpName+".wav");
try {
FileOutputStream outputStream = new FileOutputStream(tmpFile.getAbsoluteFile());
while (isRecording){
int n_size = audioRecord.read(buffer, 0, 1024);
Log.w("audiotest", "StartAudioData: ------------------------"+n_size);
try {
outputStream.write(buffer);
} catch (IOException e) {
e.printStackTrace();
}
}
outputStream.close();
pcmToWave(tmpFile.getAbsolutePath(), tmpOutFile.getAbsolutePath());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public File createFile(String name) {
String dirPath = Environment.getExternalStorageDirectory().getPath()+"/AudioRecord/";
File file = new File(dirPath);
if(!file.exists()) {
file.mkdirs();
}
String filePath = dirPath +name;
File objFile = new File(filePath);
if (!objFile.exists()) {
try {
objFile.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
return objFile;
}
return null;
}
public void stopRecord(){//停止录音
isRecording = false;
audioRecord.stop();
audioRecord.release();
try {
outstream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public void pcmToWave(String inFileName, String outFileName){
FileInputStream in = null;
FileOutputStream out = null;
long totalAudiolen = 0;
long longSamplRate = 11025;
long totalDataLen = totalAudiolen+36;//由于不包括RIFF和WAV
int channels = 2;
long byteRate = 16*longSamplRate*channels/8;
byte[] data = new byte[1024];
try {
in = new FileInputStream(inFileName);
out = new FileOutputStream(outFileName);
totalAudiolen = in.getChannel().size();
totalDataLen = totalAudiolen+36;
writeWaveFileHeader(out, totalAudiolen, totalDataLen, longSamplRate, channels, byteRate);
while (in.read(data) != -1) {
out.write(data);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void writeWaveFileHeader(FileOutputStream out, long totalAudioLen, long totalDataLen, long longSampleRate,
int channels, long byteRate) {
byte[] header = new byte[44];
header[0] = 'R'; // RIFF
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (totalDataLen & 0xff);//数据大小
header[5] = (byte) ((totalDataLen >> 8) & 0xff);
header[6] = (byte) ((totalDataLen >> 16) & 0xff);
header[7] = (byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W';//WAVE
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
//FMT Chunk
header[12] = 'f'; // 'fmt '
header[13] = 'm';
header[14] = 't';
header[15] = ' ';//过渡字节
//数据大小
header[16] = 16; // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
//编码方式 10H为PCM编码格式
header[20] = 1; // format = 1
header[21] = 0;
//通道数
header[22] = (byte) channels;
header[23] = 0;
//采样率，每个通道的播放速度
header[24] = (byte) (longSampleRate & 0xff);
header[25] = (byte) ((longSampleRate >> 8) & 0xff);
header[26] = (byte) ((longSampleRate >> 16) & 0xff);
header[27] = (byte) ((longSampleRate >> 24) & 0xff);
//音频数据传送速率,采样率*通道数*采样深度/8
header[28] = (byte) (byteRate & 0xff);
header[29] = (byte) ((byteRate >> 8) & 0xff);
header[30] = (byte) ((byteRate >> 16) & 0xff);
header[31] = (byte) ((byteRate >> 24) & 0xff);
// 确定系统一次要处理多少个这样字节的数据，确定缓冲区，通道数*采样位数
header[32] = (byte) (channels * 16 / 8);
header[33] = 0;
//每个样本的数据位数
header[34] = 16;
header[35] = 0;
//Data chunk
header[36] = 'd';//data
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);
try {
out.write(header, 0, 44);
} catch (IOException e) {
e.printStackTrace();
}
}
}3、设置权限
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />