Implementa getMaxAmplitude para audioRecord

Question

Estoy usando audioRecord en lugar de mediarecorder en mi aplicación funciona bien, pero tengo una lógica que depende mucho de la gran amplitud que es realmente difícil de obtener usando el audiorecord aquí es lo que estoy usando al leer el buffer

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; 
     max=0; 
     if(null != os){ 
      while(isRecording){ 
       read = recorder.read(buffer, 0, bufferSize); 
       int ab = (buffer[0] & 0xff) << 8 | buffer[1]; 
       amplitude = Math.abs(ab); 

      if(amplitude>0&&amplitude<25000) 
       isSilence=true;   
      else 
       isSilence=false; 

       //System.out.println(">>>>>>>>>>>"+amplitude); 
       if(AudioRecord.ERROR_INVALID_OPERATION != read){ 
        try { 
         os.write(buffer); 
        } catch (IOException e) { 
         e.printStackTrace(); 
        } 
       } 
      } 

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

pero esto no funciona para mí como el valor cambia muy rápido que necesito para poner en práctica algo así como getMaxAmplitude() para audioRecord.

Answer 1

Esto hace lo que quiere y más ... entonces se da salida a los puntos máximos en un archivo que es legible en Excel. (Estaba la solución de este problema por mí mismo, por lo que el tiempo es fortuita.)

package com.example.audiorecord; 

import java.io.BufferedWriter; 
import java.io.File; 
import java.io.FileWriter; 
import java.io.IOException; 
import java.text.SimpleDateFormat; 
import java.util.Calendar; 

import android.app.Activity; 
import android.media.AudioFormat; 
import android.media.AudioRecord; 
import android.media.MediaRecorder; 
import android.os.Bundle; 
import android.view.KeyEvent; 
import android.view.Menu; 
import android.view.View; 
import android.widget.Button; 


public class MainActivity extends Activity { 
     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 Thread recordingThread = null; 
     private boolean isRecording = false; 
     private String floatString = ""; 

     Calendar c = Calendar.getInstance(); 
     SimpleDateFormat df = new SimpleDateFormat("ddMMMyyyy_HHmmss"); 
     String formattedDate = df.format(c.getTime()); 

     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
      setContentView(R.layout.activity_main); 

      setButtonHandlers(); 
      enableButtons(false); 

      int bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE, 
        RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING); 
     } 

     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); 
     } 

     int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024 
     int BytesPerElement = 2; // 2 bytes in 16bit format 

     private void startRecording() { 
      final File logFile = new File("sdcard/log_"+formattedDate+".txt"); 
       if (!logFile.exists()) 
       { 
        try 
        { 
        logFile.createNewFile(); 
        } 
        catch (IOException e) 
        { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
        } 
       } 

      recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, 
        RECORDER_SAMPLERATE, RECORDER_CHANNELS, 
        RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement); 

      recorder.startRecording(); 
      isRecording = true; 
      recordingThread = new Thread(new Runnable() { 
       public void run() { 
        writeAudioDataToFile(logFile); 
       } 
      }, "AudioRecorder Thread"); 
      recordingThread.start(); 
     } 


     private void writeAudioDataToFile(File logFile) { 
      // Write the output audio in byte 

      short sData[] = new short[BufferElements2Rec]; 
      while (isRecording) { 
       // gets the voice output from microphone to byte format 

       recorder.read(sData, 0, BufferElements2Rec); 
       String sDataString = ""; 
       double sDataMax = 0; 
       for(int i=0; i<sData.length; i++){ 
        if(Math.abs(sData[i])>=sDataMax){sDataMax=Math.abs(sData[i]);}; 
        sDataString += "\n" + sDataMax; 

       } 

       try 
       { 
        //BufferedWriter for performance, true to set append to file flag 
        BufferedWriter buf = new BufferedWriter(new FileWriter(logFile, true)); 
        buf.append(sDataString); 
        buf.newLine(); 
        buf.close(); 
       } 
       catch (IOException e) 
       { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
       } 
     } 
     } 
     private void stopRecording() { 
      // stops the recording activity 
      if (null != recorder) { 
       isRecording = false; 
       recorder.stop(); 
       recorder.release(); 
       recorder = null; 
       recordingThread = null; 
      } 
     } 

     private View.OnClickListener btnClick = new View.OnClickListener() { 
      public void onClick(View v) { 
       switch (v.getId()) { 
       case R.id.btnStart: { 
        enableButtons(true); 
        startRecording(); 
        break; 
       } 
       case R.id.btnStop: { 
        enableButtons(false); 
        stopRecording(); 
        break; 
       } 
       } 
      } 
     }; 

     @Override 
     public boolean onKeyDown(int keyCode, KeyEvent event) { 
      if (keyCode == KeyEvent.KEYCODE_BACK) { 
       finish(); 
      } 
      return super.onKeyDown(keyCode, event); 
     } 



    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

} 

Answer 2

int amplitude = (buffer[0] & 0xff) << 8 | buffer[1]; 
amplitude = Math.abs(ab); 

¿Comes un error aquí? creo que debe ser

int ab = (buffer[0] & 0xff) << 8 | buffer[1]; 
int amplitude = Math.abs(ab); 

Answer 3

Si la codificación es ENCODING_PCM_16BIT, entonces debería usar

private int cAmplitude= 0; 

while(isRecording) { 
    read = recorder.read(data, 0, bufferSize); 

    for (int i=0; i<read/2; i++) { 
     short curSample = getShort(data[i*2], data[i*2+1]); 
     if (curSample > cAmplitude) { 
      cAmplitude = curSample; 
     } 
    } 

    Log.d("amplitude",Integer.toString(cAmplitude)); 
    cAmplitude = 0; 
} 

private short getShort(byte argB1, byte argB2) { 
    return (short)(argB1 | (argB2 << 8)); 
} 

Para obtener más información, echar un vistazo a How to record voice in "wav" format in Android