public class AudioUtil {
/**
* 采样率，现在能够保证在所有设备上使用的采样率是44100Hz, 但是其他的采样率（22050, 16000, 11025）在一些设备上也可以使用。
*/
public static final int SAMPLE_RATE_INHZ = 44100;
/**
* 声道数。CHANNEL_IN_MONO and CHANNEL_IN_STEREO. 其中CHANNEL_IN_MONO是可以保证在所有设备能够使用的。
*/
public static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_MONO;
/**
* 返回的音频数据的格式。 ENCODING_PCM_8BIT, ENCODING_PCM_16BIT, and ENCODING_PCM_FLOAT.
*/
public static final int AUDIO_FORMAT = AudioFormat.ENCODING_PCM_16BIT;
private static final String TAG = "AudioUtil";
private static AudioRecord audioRecord;
private static String mPath = Environment.getExternalStorageDirectory().getAbsolutePath()
+"/录音/";
public static boolean isRecording;
private static long mAudioName;
private static long sEndTime;
private static long sDuration;
/**
* 开始录音
* @param callBack
*/
public static void startRecord(final ResultCallBack callBack) {
//当前时间的毫秒
mAudioName = System.currentTimeMillis();
final int minBufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE_INHZ, CHANNEL_CONFIG, AUDIO_FORMAT);
audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE_INHZ,
CHANNEL_CONFIG, AUDIO_FORMAT, minBufferSize);
final byte data[] = new byte[minBufferSize];
final File file = new File(mPath, mAudioName+".pcm");
if (!file.mkdirs()) {
Log.e(TAG, "Directory not created");
}
if (file.exists()) {
file.delete();
}
//录音
audioRecord.startRecording();
isRecording = true;
//将录音写入本地文件
new Thread(new Runnable() {
@Override
public void run() {
FileOutputStream os = null;
try {
os = new FileOutputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
if (null != os) {
while (isRecording) {
int read = audioRecord.read(data, 0, minBufferSize);
// 如果读取音频数据没有出现错误，就将数据写入到文件
if (AudioRecord.ERROR_INVALID_OPERATION != read) {
try {
os.write(data);
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
Log.i(TAG, "run: close file output stream !");
os.close();
} catch (IOException e) {
e.printStackTrace();
callBack.onFail(e.toString());
}
sEndTime = System.currentTimeMillis();
sDuration = sEndTime - mAudioName;
//将PCM格式的录音转换为wav的,方便播放
PcmToWavUtil pcmToWavUtil = new PcmToWavUtil(SAMPLE_RATE_INHZ, CHANNEL_CONFIG, AUDIO_FORMAT);
File pcmFile = new File(mPath, mAudioName+".pcm");
File wavFile = new File(mPath, mAudioName+".wav");
if (!wavFile.mkdirs()) {
Log.e(TAG, "wavFile Directory not created");
}
if (wavFile.exists()) {
wavFile.delete();
}
pcmToWavUtil.pcmToWav(pcmFile.getAbsolutePath(), wavFile.getAbsolutePath());
//将结果回调给调用者
callBack.onSuccess(wavFile.getAbsolutePath(),sDuration);
}
}
}).start();
}
/**
* 停止录音
*/
public static void stopRecord() {
isRecording = false;
// 释放资源
if (null != audioRecord) {
audioRecord.stop();
audioRecord.release();
audioRecord = null;
//recordingThread = null;
}
}
/**
* 将pcm音频文件转换为wav音频文件
*/
public static class PcmToWavUtil {
/**
* 缓存的音频大小
*/
private static int mBufferSize;
/**
* 采样率
*/
private static int mSampleRate;
/**
* 声道数
*/
private static int mChannel;
/**
* @param sampleRate sample rate、采样率
* @param channel channel、声道
* @param encoding Audio data format、音频格式
*/
PcmToWavUtil(int sampleRate, int channel, int encoding) {
this.mSampleRate = sampleRate;
this.mChannel = channel;
this.mBufferSize = AudioRecord.getMinBufferSize(mSampleRate, mChannel, encoding);
}
/**
* pcm文件转wav文件
*
* @param inFilename 源文件路径
* @param outFilename 目标文件路径
*/
public static void pcmToWav(String inFilename, String outFilename) {
FileInputStream in;
FileOutputStream out;
long totalAudioLen;
long totalDataLen;
long longSampleRate = mSampleRate;
int channels = mChannel == AudioFormat.CHANNEL_IN_MONO ? 1 : 2;
long byteRate = 16 * mSampleRate * channels / 8;
byte[] data = new byte[mBufferSize];
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 (IOException e) {
e.printStackTrace();
}
}
/**
* 加入wav文件头
*/
private static void writeWaveFileHeader(FileOutputStream out, long totalAudioLen,
long totalDataLen, long longSampleRate, int channels, long byteRate)
throws IOException {
byte[] header = new byte[44];
// RIFF/WAVE header
header[0] = 'R';
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);
//WAVE
header[8] = 'W';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
// 'fmt ' chunk
header[12] = 'f';
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
// 4 bytes: size of 'fmt ' chunk
header[16] = 16;
header[17] = 0;
header[18] = 0;
header[19] = 0;
// format = 1
header[20] = 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);
// block align
header[32] = (byte) (2 * 16 / 8);
header[33] = 0;
// bits per sample
header[34] = 16;
header[35] = 0;
//data
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);
}
}
public interface ResultCallBack{
void onSuccess(String path, long time);
void onFail(String msg);
}
}
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