Mega Code Archive
Write Date to AudioTrack
<![CDATA[
package app.test;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class Test extends Activity implements OnTouchListener {
AudioSynthesisTask audioSynth;
float BASE_FREQUENCY = 440,synth_frequency = BASE_FREQUENCY; // 440 Hz, Middle A
boolean play = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
View mainView = this.findViewById(R.id.MainView);
mainView.setOnTouchListener(this);
audioSynth = new AudioSynthesisTask();
audioSynth.execute();
}
@Override
public void onPause() {
super.onPause();
play = false;
finish();
}
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
play = true;
synth_frequency = event.getX() + BASE_FREQUENCY;
break;
case MotionEvent.ACTION_MOVE:
play = true;
synth_frequency = event.getX() + BASE_FREQUENCY;
break;
case MotionEvent.ACTION_UP:
play = false;
break;
case MotionEvent.ACTION_CANCEL:
break;
default:
break;
}
return true;
}
private class AudioSynthesisTask extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
final int SAMPLE_RATE = 11025;
int minSize = AudioTrack.getMinBufferSize(SAMPLE_RATE,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT);
AudioTrack audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
SAMPLE_RATE, AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT, minSize,
AudioTrack.MODE_STREAM);
audioTrack.play();
short[] buffer = new short[minSize];
float angle = 0;
while (true) {
if (play) {
for (int i = 0; i < buffer.length; i++) {
float angular_frequency = (float) (2 * Math.PI) * synth_frequency / SAMPLE_RATE;
buffer[i] = (short) (Short.MAX_VALUE * ((float) Math.sin(angle)));
angle += angular_frequency;
}
audioTrack.write(buffer, 0, buffer.length);
}
}
}
}
}
//main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="@+id/MainView"
>
</LinearLayout>
]]>