Android AudioRecord - Won't Initialize 2nd time

Question

Hej, im currently trying to get AudioRecord to work. Because I need it in a bigger project. But it seems to mess up a lot. I have been trying alot of things, so I went back to basic when I traced this bug. I am using my Samsung Galaxy S as my debugdevice.

My problem is, first time after a reboot of my device I can initialize the AudioRecord object I create without problems. But the second time I run it, it won't initialize the AudioRecord object. I have tried several frequencies, fyi.

Here is my code:

package android.audiorecordtest;

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

public class AudioRecordTest extends Activity {

    int frequency;
    AudioRecord audRec;
    TextView txtVw;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        txtVw = (TextView) findViewById(R.id.txtVw);


        frequency=8000;
        int bufferSize=(AudioRecord.getMinBufferSize(frequency, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT))*2;
        if (bufferSize>0) {
            audRec = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize);
                int status = audRec.getState();
        if (status == AudioRecord.STATE_INITIALIZED) {
            txtVw.setText("Initialized" + frequency);
        } else {
            txtVw.setText("Not Initialized i=" + frequency);
        }
        }

After a few hours of looking through logcat information i found this event

    02-28 10:46:37.048: DEBUG/dalvikvm(4477): GC_EXPLICIT freed 1801 objects / 98944 bytes in 97ms
02-28 10:46:37.048: VERBOSE/AudioRecord(4477): stop

Which seems to "release the native hold on the AudioRecord. So i tried doing an override of finalize with my Audiorecord object.release(). This didnt work though.. Anyone have any idea?

Answer 1

I was able to reproduce your problem (on a Samsung phone). I added an onDestroy() method releasing the record:

@Override
public void onDestroy() { 
    super.onDestroy();
    System.out.println("OnDestroy");
    audRec.release();
}

After adding this, the audioRecord seems to initialize correctly every time the activity is started.