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?
To Answer my own question, the only way i found it doable to use AudioRecord, is to never have it as an global variable, dont know why, but it seems it won't let you release the resources of the instance correctly if you do so.
My AudioRecord didn't initialize because it was static
I was able to reproduce your problem (on a Samsung phone). I added an onDestroy() method releasing the record:
After adding this, the audioRecord seems to initialize correctly every time the activity is started.
You should try to call audRec.stop() to release the resource.
I had the same problem, usually the audRec.release() helps indeed, but if you need to stop and start several times the following code is more robust. Plus, I had an issue that the recording took place in a separate thread and Android sometimes kills threads when running for a long time. So take a look at this code, it makes sure the recording is held even when the other thread is dead and upon the following audRec.start() it stops and releases:
Then if you have a recorder thread you can use it as follows: