Android：AudioRecord 一个波形，单声道文件
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【中文标题】Android：AudioRecord 一个波形，单声道文件【英文标题】：Android: AudioRecord a wave, mono file 【发布时间】：2014-07-28 13:25:28 【问题描述】：我想为安卓应用录制声音，波形格式，16 位/单声道（1 声道）。我使用了这段代码：
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity
private static final int RECORDER_BPP = 16;
private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
private static final String AUDIO_RECORDER_TEMP_FILE = "record_temp.raw";
private static final int RECORDER_SAMPLERATE = 44100;
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private AudioRecord recorder = null;
private int bufferSize = 0;
private Thread recordingThread = null;
private boolean isRecording = false;
@SuppressWarnings("deprecation")
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
setButtonHandlers();
enableButtons(false);
bufferSize = AudioRecord.getMinBufferSize(8000,AudioFormat.CHANNEL_IN_MONO,AudioFormat.ENCODING_PCM_16BIT);
private void setButtonHandlers()
((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
private void enableButton(int id,boolean isEnable)
((Button)findViewById(id)).setEnabled(isEnable);
private void enableButtons(boolean isRecording)
enableButton(R.id.btnStart,!isRecording);
enableButton(R.id.btnStop,isRecording);
private String getFilename()
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,AUDIO_RECORDER_FOLDER);
if(!file.exists())
file.mkdirs();
return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + AUDIO_RECORDER_FILE_EXT_WAV);
private String getTempFilename()
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,AUDIO_RECORDER_FOLDER);
if(!file.exists())
file.mkdirs();
File tempFile = new File(filepath,AUDIO_RECORDER_TEMP_FILE);
if(tempFile.exists())
tempFile.delete();
return (file.getAbsolutePath() + "/" + AUDIO_RECORDER_TEMP_FILE);
private void startRecording()
recorder = new AudioRecord(MediaRecorder.Audiosource.MIC,
RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);
int i = recorder.getState();
if(i==1)
recorder.startRecording();
isRecording = true;
recordingThread = new Thread(new Runnable()
@Override
public void run()
writeAudioDataToFile();
,"AudioRecorder Thread");
recordingThread.start();
private void writeAudioDataToFile()
byte data[] = new byte[bufferSize];
String filename = getTempFilename();
FileOutputStream os = null;
try
os = new FileOutputStream(filename);
catch (FileNotFoundException e)
// TODO Auto-generated catch block
e.printStackTrace();
int read = 0;
if(null != os)
while(isRecording)
read = recorder.read(data, 0, bufferSize);
if(AudioRecord.ERROR_INVALID_OPERATION != read)
try
os.write(data);
catch (IOException e)
e.printStackTrace();
try
os.close();
catch (IOException e)
e.printStackTrace();
private void stopRecording()
if(null != recorder)
isRecording = false;
int i = recorder.getState();
if(i==1)
recorder.stop();
recorder.release();
recorder = null;
recordingThread = null;
copyWaveFile(getTempFilename(),getFilename());
deleteTempFile();
private void deleteTempFile()
File file = new File(getTempFilename());
file.delete();
private void copyWaveFile(String inFilename,String outFilename)
FileInputStream in = null;
FileOutputStream out = null;
long totalAudioLen = 0;
long totalDataLen = totalAudioLen + 36;
long longSampleRate = RECORDER_SAMPLERATE;
int channels = 1;
long byteRate = RECORDER_BPP * RECORDER_SAMPLERATE * channels/8;
byte[] data = new byte[bufferSize];
try
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
totalAudioLen = in.getChannel().size();
totalDataLen = totalAudioLen + 36;
// AppLog.logString("File size: " + totalDataLen);
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();
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] = RECORDER_BPP; // 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);
private View.OnClickListener btnClick = new View.OnClickListener()
@Override
public void onClick(View v)
switch(v.getId())
case R.id.btnStart:
// AppLog.logString("Start Recording");
enableButtons(true);
startRecording();
break;
case R.id.btnStop:
// AppLog.logString("Start Recording");
enableButtons(false);
stopRecording();
break;
;
但记录始终是立体声通道，32 位。我使用了 AudioFormat.CHANNEL_IN_MONO 和 AudioFormat.ENCODING_PCM_16BIT。
有人可以帮我吗？
【问题讨论】：
奇怪，我之前使用过完全相同的代码示例并且没有这个问题。让我看看 你如何检查它是以 2 个频道而不是 1 个频道出现的？ 我正在检查 Audacity，文件音频是立体声没有单声道。 你能贴一张大胆波形的截图吗？我没有看到它应该以立体声出现的任何理由，看起来你已经正确设置了一切。 图片无法复制，抱歉 【参考方案1】：根据 cmets 中讨论的内容，如果您从大约 3 秒的音频中获取 528 kb 的文件，那么发生了两件事中的一件。要么你是用立体声录音（如果你说你看到两个声道大胆，并且因为 android 不支持 32 位 PCM 编码，这两者似乎更有可能），或者你正在用 32 位样本录制一个频道。奇怪的是，大胆会告诉你文件样本大小是 32 位/样本。
我的理由是
(44100 hz * 3 seconds * 32 bits/sample) = 528 kb
and
2 channels * (44100 hz * 3 seconds * 16 bits/sample) = 528 kb
由于您正确设置了 audioRecorder 对象，我不确定第二个通道的形成位置。我建议在 copyWaveFile 方法中处理 byteRate long 中的值并查看对音频文件的影响。
【讨论】：
【参考方案2】：您的标题似乎包含错误：
header[32] = (byte) (2 * 16 / 8); // block align
应该是
header[32] = (byte) (1 * 16 / 8); // block align
这应该是channels*RECORDER_BPP/8
我已经尝试过了，它似乎有效。
【讨论】：
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