How to record many Audio Recorder?


I’m a beginner in Processing, here is a code to record an audio from micro input. (from minim library)

The sketch allow to record an audio but just only one recording.

I would like to record a new recording at each time we press to the r key.

Is someone can help me please ?

Thank’s in advance

  * This sketch demonstrates how to an <code>AudioRecorder</code> to record audio to disk. 
  * To use this sketch you need to have something plugged into the line-in on your computer, 
  * or else be working on a laptop with an active built-in microphone. 
  * <p>
  * Press 'r' to toggle recording on and off and the press 's' to save to disk. 
  * The recorded file will be placed in the sketch folder of the sketch.
  * <p>
  * For more information about Minim and additional features, 
  * visit

import ddf.minim.*;

Minim minim;
AudioInput in;
AudioRecorder recorder;

void setup()
  size(512, 200, P3D);
  minim = new Minim(this);

  in = minim.getLineIn();
  // create a recorder that will record from the input to the filename specified
  // the file will be located in the sketch's root folder.
  recorder = minim.createRecorder(in, "myrecording.wav");
  textFont(createFont("Arial", 12));

void draw()
  // 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.bufferSize() - 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("Currently recording...", 5, 15);
    text("Not recording.", 5, 15);

void keyReleased()
  if ( key == 'r' ) 
    // to indicate that you want to start or stop capturing audio data, you must call
    // beginRecord() and endRecord() 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 the buffer 
    // (in the case of buffered recording) or to the end of the file (in the case of streamed recording). 
    if ( recorder.isRecording() ) 
  if ( key == 's' )
    // we've filled the file out buffer, 
    // now write it to the file we specified in createRecorder
    // in the case of buffered recording, if the buffer is large, 
    // this will appear to freeze the sketch for sometime
    // 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.
    // the method returns the recorded audio as an AudioRecording, 
    // see the example  AudioRecorder >> RecordAndPlayback for more about that;
    println("Done saving.");

1 Like

it looks like here is a good answer

1 Like

Thank’s for the reply, it helps but the first time we record, the first recording doesn’t work

it didn’t work in my case. when i started to record the program crashes and prints this error in the console: ==== JavaSound Minim Error ====
==== Error obtaining new output stream: E:\Users\ezequ\OneDrive\Escritorio\facu\MULTIMEDIA\informatica aplicada I\minim\minim\examples\Basics\RecordAudioOutput\myrecording - Sun Jun 26 18:49:52 ART 2022.wav (El nombre de archivo, el nombre de directorio o la sintaxis de la etiqueta del volumen no son correctos)

java.lang.NullPointerException: Cannot invoke “org.tritonus.share.sampled.file.AudioOutputStream.write(byte, int, int)” because “this.aos” is null
at ddf.minim.javasound.JSStreamingSampleRecorder.samples(
at ddf.minim.SignalSplitter.samples(
Could not run the sketch (Target VM failed to initialize).
For more information, read Help ? Troubleshooting.