I want to do some Audio signal processing in the platform of Android. So I use AudioTrack record sounds clip with 10s. However, when I check the record data file, I found there is a bunch of zeros in the very beginning in every time. Can someone tell me why it like that. And how to eliminate those zeros. Thank you!

Here is my code: 1. Initialize a new file for data stroage:

 file = new File(Environment.getExternalStorageDirectory(), "RecordFile");     if (file.exists()) file.delete();      try {         file.createNewFile();     } catch (IOException e) {         e.printStackTrace();     } 

2. Paras:

private static final int Encording = AudioFormat.ENCODING_PCM_16BIT; public static final int Sample_rate = 48000; private static final int Channel = AudioFormat.CHANNEL_IN_MONO; public static final int Buffersize = AudioRecord.getMinBufferSize(Sample_rate, Channel, Encording); 

3. Record

   private void AudioRecord() {    try {       AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, Sample_rate, Channel, Encording, Buffersize);       DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(MainActivity.file)));       short[] buffer = new short[Buffersize / 2];        audioRecord.startRecording(); // Start record     /*******************************************************************************************************/     while (MainActivity.isrecord) {         audioRecord.read(buffer, 0, buffer.length);         for (int i = 0; i < buffer.length; i++) {             dos.writeShort(buffer[i]);         }     }     audioRecord.stop();     audioRecord.release();     dos.close(); } catch (FileNotFoundException e) {     e.printStackTrace(); } catch (IOException e) {     e.printStackTrace(); } 

   }