How can i Detect user voice in PCM file using android application

Question

I am Working on application to detect what user says, that means if user start to talk application begins to Record sound coming from microphone and then when user stops talking application stops recording and saves the recorded audio.

The following code should do that, but my problem is that this code converts from PCM to .WAV and i don't want that... what changes should i make on the code in order to keep it in PCM??

and my other issue is that this code keeps giving me the following error:

RECORDER_BPP cannot be resolved to a variable

so my question is :

• 1- How to resolve this error: RECORDER_BPP cannot be resolved to a variable.

• 2- How to edit this code to keep it PCM.

    public void onCreate(Bundle savedInstanceState) 
  {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
  
  // Get the minimum buffer size required for the successful creation of an AudioRecord object. 
  int bufferSizeInBytes = AudioRecord.getMinBufferSize( RECORDER_SAMPLERATE,
                                                        RECORDER_CHANNELS,
                                                        RECORDER_AUDIO_ENCODING
                                                       ); 
  // Initialize Audio Recorder.
  AudioRecord audioRecorder = new AudioRecord( MediaRecorder.AudioSource.MIC,
                                               RECORDER_SAMPLERATE,
                                               RECORDER_CHANNELS,
                                               RECORDER_AUDIO_ENCODING,
                                               bufferSizeInBytes
                                              );
  // Start Recording.
  audioRecorder.startRecording();
  
  int numberOfReadBytes   = 0; 
  byte audioBuffer[]      = new  byte[bufferSizeInBytes];
  boolean recording       = false;
  float tempFloatBuffer[] = new float[3];
  int tempIndex           = 0;
  int totalReadBytes      = 0;
  byte totalByteBuffer[]  = new byte[60 * 44100 * 2];
  
  
  // While data come from microphone. 
  while( true )
  {
      float totalAbsValue = 0.0f;
      short sample        = 0; 
  
      numberOfReadBytes = audioRecorder.read( audioBuffer, 0, bufferSizeInBytes );
  
      // Analyze Sound.
      for( int i=0; i<bufferSizeInBytes; i+=2 ) 
      {
          sample = (short)( (audioBuffer[i]) | audioBuffer[i + 1] << 8 );
          totalAbsValue += Math.abs( sample ) / (numberOfReadBytes/2);
      }
  
      // Analyze temp buffer.
      tempFloatBuffer[tempIndex%3] = totalAbsValue;
      float temp                   = 0.0f;
      for( int i=0; i<3; ++i )
          temp += tempFloatBuffer[i];
  
      if( (temp >=0 && temp <= 350) && recording == false )
      {
          Log.i("TAG", "1");
          tempIndex++;
          continue;
      }
  
      if( temp > 350 && recording == false )
      {
          Log.i("TAG", "2");
          recording = true;
      }
  
      if( (temp >= 0 && temp <= 350) && recording == true )
      {
          Log.i("TAG", "Save audio to file.");
  
          // Save audio to file.
          String filepath = Environment.getExternalStorageDirectory().getPath();
          File file = new File(filepath,"AudioRecorder");
          if( !file.exists() )
              file.mkdirs();
  
          String fn = file.getAbsolutePath() + "/" + System.currentTimeMillis() + ".wav";
  
          long totalAudioLen  = 0;
          long totalDataLen   = totalAudioLen + 36;
          long longSampleRate = RECORDER_SAMPLERATE;
          int channels        = 1;
          long byteRate       = RECORDER_BPP * RECORDER_SAMPLERATE * channels/8;
          totalAudioLen       = totalReadBytes;
          totalDataLen        = totalAudioLen + 36;
          byte finalBuffer[]  = new byte[totalReadBytes + 44];
  
          finalBuffer[0] = 'R';  // RIFF/WAVE header
          finalBuffer[1] = 'I';
          finalBuffer[2] = 'F';
          finalBuffer[3] = 'F';
          finalBuffer[4] = (byte) (totalDataLen & 0xff);
          finalBuffer[5] = (byte) ((totalDataLen >> 8) & 0xff);
          finalBuffer[6] = (byte) ((totalDataLen >> 16) & 0xff);
          finalBuffer[7] = (byte) ((totalDataLen >> 24) & 0xff);
          finalBuffer[8] = 'W';
          finalBuffer[9] = 'A';
          finalBuffer[10] = 'V';
          finalBuffer[11] = 'E';
          finalBuffer[12] = 'f';  // 'fmt ' chunk
          finalBuffer[13] = 'm';
          finalBuffer[14] = 't';
          finalBuffer[15] = ' ';
          finalBuffer[16] = 16;  // 4 bytes: size of 'fmt ' chunk
          finalBuffer[17] = 0;
          finalBuffer[18] = 0;
          finalBuffer[19] = 0;
          finalBuffer[20] = 1;  // format = 1
          finalBuffer[21] = 0;
          finalBuffer[22] = (byte) channels;
          finalBuffer[23] = 0;
          finalBuffer[24] = (byte) (longSampleRate & 0xff);
          finalBuffer[25] = (byte) ((longSampleRate >> 8) & 0xff);
          finalBuffer[26] = (byte) ((longSampleRate >> 16) & 0xff);
          finalBuffer[27] = (byte) ((longSampleRate >> 24) & 0xff);
          finalBuffer[28] = (byte) (byteRate & 0xff);
          finalBuffer[29] = (byte) ((byteRate >> 8) & 0xff);
          finalBuffer[30] = (byte) ((byteRate >> 16) & 0xff);
          finalBuffer[31] = (byte) ((byteRate >> 24) & 0xff);
          finalBuffer[32] = (byte) (2 * 16 / 8);  // block align
          finalBuffer[33] = 0;
          finalBuffer[34] = RECORDER_BPP;  // bits per sample
          finalBuffer[35] = 0;
          finalBuffer[36] = 'd';
          finalBuffer[37] = 'a';
          finalBuffer[38] = 't';
          finalBuffer[39] = 'a';
          finalBuffer[40] = (byte) (totalAudioLen & 0xff);
          finalBuffer[41] = (byte) ((totalAudioLen >> 8) & 0xff);
          finalBuffer[42] = (byte) ((totalAudioLen >> 16) & 0xff);
          finalBuffer[43] = (byte) ((totalAudioLen >> 24) & 0xff);
  
          for( int i=0; i<totalReadBytes; ++i )
              finalBuffer[44+i] = totalByteBuffer[i];
  
          FileOutputStream out;
          try {
              out = new FileOutputStream(fn);
               try {
                      out.write(finalBuffer);
                      out.close();
                  } catch (IOException e) {
                      // TODO Auto-generated catch block
                      e.printStackTrace();
                  }
  
          } catch (FileNotFoundException e1) {
              // TODO Auto-generated catch block
              e1.printStackTrace();
          }
  
          //*/
          tempIndex++;
          break;
      }
  
      // -> Recording sound here.
      Log.i( "TAG", "Recording Sound." );
      for( int i=0; i<numberOfReadBytes; i++ )
          totalByteBuffer[totalReadBytes + i] = audioBuffer[i];
      totalReadBytes += numberOfReadBytes;
      //*/
  
      tempIndex++;
  
     }
     }
  

Here is the like where I got the CODE: Voice Detection in Android Application

Answer 1

The problem turned out to be very simple,,, you must just add this statement to your code, and all well work out well.

private static final int RECORDER_BPP = 16;