Skip to content

Instantly share code, notes, and snippets.

@luisdelarosa
Created February 20, 2014 04:15
Show Gist options
  • Save luisdelarosa/9107008 to your computer and use it in GitHub Desktop.
Save luisdelarosa/9107008 to your computer and use it in GitHub Desktop.
package com.example.frequencytest;
import android.app.Activity;
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.Menu;
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 MainActivity extends Activity implements OnClickListener {
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;
//AudioRecord audioRecord;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
startStopButton = (Button) this.findViewById(R.id.start_stop_btn);
startStopButton.setOnClickListener(this);
transformer = new RealDoubleFFT(blockSize);
imageView = (ImageView) this.findViewById(R.id.imageView1);
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);
}
public class RecordAudio extends AsyncTask<Void, double[], Void> {
@Override
protected Void doInBackground(Void... arg0) {
try {
// int bufferSize = AudioRecord.getMinBufferSize(frequency,
// AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
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();
// started = true; hopes this should true before calling
// following while loop
while (started) {
int bufferReadResult = audioRecord.read(buffer, 0,
blockSize);
for (int i = 0; i < blockSize && i < bufferReadResult; i++) {
toTransform[i] = (double) buffer[i] / 32768.0; // signed
// 16
} // bit
transformer.ft(toTransform);
publishProgress(toTransform);
}
audioRecord.stop();
} catch (Throwable t) {
t.printStackTrace();
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();
// TODO Auto-generated method stub
// super.onProgressUpdate(values);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (started) {
started = false;
startStopButton.setText("Start");
recordTask.cancel(true);
} else {
started = true;
startStopButton.setText("Stop");
recordTask = new RecordAudio();
recordTask.execute();
}
}
}
@AndriesJacobus
Copy link

Hey man, I was wandering if you could help me out with an adaptation I want to bring into you code?

I want to alter it so that the visualization will be shown across the screen width and not just in the buffer zone you allocated (256dp). I was able to get the screen width with the following code:

Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
width = size.x;

Now I would just like to know how to stretch your visualization across this width?

Thank you for the help!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment