import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import ca.uol.aig.fftpack.RealDoubleFFT;
public class AudioProcessing extends Activity implements OnClickListener{
// AudioRecord 객체에서 주파수는 8kHz, 오디오 채널은 하나, 샘플은 16비트를 사용
int frequency = 8000;
int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO;
int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
private RealDoubleFFT transformer;
int blockSize = 256;
Button startStopButton;
boolean started = false;
RecordAudio recordTask;
ImageView imageView;
Bitmap bitmap;
Canvas canvas;
Paint paint;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startStopButton = (Button)findViewById(R.id.StartStopButton);
startStopButton.setOnClickListener(this);
transformer = new RealDoubleFFT(blockSize);
imageView = (ImageView)findViewById(R.id.ImageView01);
bitmap = Bitmap.createBitmap((int)256, (int)100, Bitmap.Config.ARGB_8888);
canvas = new Canvas(bitmap);
paint = new Paint();
paint.setColor(Color.GREEN);
imageView.setImageBitmap(bitmap);
}
private class RecordAudio extends AsyncTask<Void, double[], Void>{
@Override
protected Void doInBackground(Void... params) {
try{
int bufferSize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding);
AudioRecord audioRecord = new AudioRecord(
MediaRecorder.AudioSource.MIC, frequency, channelConfiguration, audioEncoding, bufferSize);
short[] buffer = new short[blockSize];
double[] toTransform = new double[blockSize];
audioRecord.startRecording();
while(started){
int bufferReadResult = audioRecord.read(buffer, 0, blockSize);
for(int i = 0; i < blockSize && i < bufferReadResult; i++){
toTransform[i] = (double)buffer[i] / Short.MAX_VALUE; // 부호 있는 16비트
}
transformer.ft(toTransform);
publishProgress(toTransform);
}
audioRecord.stop();
}catch(Throwable t){
Log.e("AudioRecord", "Recording Failed");
}
return null;
}
@Override
protected void onProgressUpdate(double[]... toTransform) {
canvas.drawColor(Color.BLACK);
for(int i = 0; i < toTransform[0].length; i++){
int x = i;
int downy = (int) (100 - (toTransform[0][i] * 10));
int upy = 100;
canvas.drawLine(x, downy, x, upy, paint);
}
imageView.invalidate();
}
}
@Override
public void onClick(View arg0) {
if(started){
started = false;
startStopButton.setText("Start");
recordTask.cancel(true);
}else{
started = true;
startStopButton.setText("Stop");
recordTask = new RecordAudio();
recordTask.execute();
}
}
}