使用 AudioRecord API 的 android 录音机

Question

我是安卓新手。我想使用 AndroidRecord API 构建一个录音机 android 来获取 .wav 文件，因为要进一步处理声音格式必须是 .wav。经过搜索和一些试验，我无法得到我想要的。任何帮助将不胜感激。

Answer 1

Andoid AudioRecord 和 MediaRecorder 库不支持wav格式。但这是一个解决方案。将此类复制到您的代码中:

public class WavRecorder {
 private static final int RECORDER_BPP = 16;
 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;
 short[] audioData;

 private AudioRecord recorder = null;
 private int bufferSize = 0;
 private Thread recordingThread = null;
 private boolean isRecording = false;
 int[] bufferData;
 int bytesRecorded;

 private String output;

 public WavRecorder(String path) {
  bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,
    RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING) * 3;

  audioData = new short[bufferSize]; // short array that pcm data is put
           // into.
  output = path;

 }

 private String getFilename() {
  return (output);
 }

 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);
 }

 public 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) {
   e.printStackTrace();
  }

  int read = 0;
  if (null != os) {
   while (isRecording) {
    read = recorder.read(data, 0, bufferSize);
    if (read > 0) {
    }

    if (AudioRecord.ERROR_INVALID_OPERATION != read) {
     try {
      os.write(data);
     } catch (IOException e) {
      e.printStackTrace();
     }
    }
   }

   try {
    os.close();
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }

 public 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 = ((RECORDER_CHANNELS == AudioFormat.CHANNEL_IN_MONO) ? 1
    : 2);
  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;

   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) (((RECORDER_CHANNELS == AudioFormat.CHANNEL_IN_MONO) ? 1
    : 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);
 }
}

然后像这样使用它:

WavRecorder wavRecorder = new WavRecorder("path_to_file.wav");
wavRecorder.startRecording();
//do something else...
wavRecorder.stopRecording();

此代码复制自 this blog发布。