Record and Playback Audio - Processing

For more information about Minim and additional features, visit http://code.compartmental.net/minim/

/**
  * This sketch demonstrates how to use an AudioRecorder to record audio to disk
  * and then immediately play it back by creating a new FilePlayer using the AudioRecordingStream
  * returned by the save method.
  * 
 
  * To use this sketch you need to have something plugged into the line-in on your computer.

  * Press 'r' to toggle recording on and off and the press 's' to save to disk.

  * The recorded file will be placed in the main folder of the sketch.
  * 

  * For more information about Minim and additional features, visit http://code.compartmental.net/minim/
  */

import ddf.minim.*;
import ddf.minim.ugens.*;

Minim minim;

// for recording
AudioInput in;
AudioRecorder recorder;
boolean recorded;
int nb = 0;

// for playing back
AudioOutput out;
FilePlayer player;

void setup()
{
  size(512, 200, P3D);

  minim = new Minim(this);

  // get a stereo line-in: sample buffer length of 2048
  // default sample rate is 44100, default bit depth is 16
  in = minim.getLineIn(Minim.STEREO, 2048);

  // create an AudioRecorder that will record from in to the filename specified.
  // the file will be located in the sketch's main folder.
  recorder = minim.createRecorder(in, "myrecording.wav");

  // get an output we can playback the recording on
  out = minim.getLineOut( Minim.STEREO );

  textFont(createFont("Arial", 12));
}

void draw()
{
  background(0); 
  stroke(255);
  // draw the waveforms
  // the values returned by left.get() and right.get() will be between -1 and 1,
  // so we need to scale them up to see the waveform
  for(int i = 0; i < in.left.size()-1; i++)
  {
    line(i, 50 + in.left.get(i)*50, i+1, 50 + in.left.get(i+1)*50);
    line(i, 150 + in.right.get(i)*50, i+1, 150 + in.right.get(i+1)*50);
  }

  if ( recorder.isRecording() )
  {
    text("Now recording, press the r key to stop recording.", 5, 15);
  }
  else if ( !recorded )
  {
    text("Press the r key to start recording.", 5, 15);
  }
  else
  {
    text("Press the s key to save the recording to disk and play it back in the sketch.", 5, 15);
  }
}

void keyReleased()
{
  if ( !recorded && key == 'r' ) 
  {
    // to indicate that you want to start or stop capturing audio data, 
    // you must callstartRecording() and stopRecording() on the AudioRecorder object. 
    // You can start and stop as many times as you like, the audio data will 
    // be appended to the end of to the end of the file. 

    if ( recorder.isRecording() ) 
    {
      recorder.endRecord();
      recorded = true;
    }
    else 
    {
      recorder.beginRecord();
    }
  }
  if ( recorded && key == 's' )
  {
    // we've filled the file out buffer, 
    // now write it to a file of the type we specified in setup
    // in the case of buffered recording, 
    // this will appear to freeze the sketch for sometime, if the buffer is large
    // in the case of streamed recording, 
    // it will not freeze as the data is already in the file and all that is being done
    // is closing the file.
    // save returns the recorded audio in an AudioRecordingStream, 
    // which we can then play with a FilePlayer
    if ( player != null )
    {
        player.unpatch( out );
        player.close();
    }
    player = new FilePlayer( recorder.save() );
    player.patch( out );
    player.play();
    // create a new recorder to record again
    nb ++;
    recorder = minim.createRecorder(in, "myrecording"+nb+".wav");
    recorded = false;
  }
}