Getting Multiple Audio Inputs in Processing

Question

I\'m currently writing a Processing sketch that needs to access multiple audio inputs, but Processing only allows access to the default line in. I have tried getting Lines

Answer 1

I had the same issue a few years ago and I used a combination of JACK, JNAJack and Beads. You can follow this Beads Google Group thread for more details.

At the that time I had to use this version of Beads (2012-04-23), but I hope those changes probably made it into the main project by now.

For reference, here is the basic class I used:

import java.util.Arrays;

import org.jaudiolibs.beads.AudioServerIO;

import net.beadsproject.beads.analysis.featureextractors.FFT;
import net.beadsproject.beads.analysis.featureextractors.PowerSpectrum;
import net.beadsproject.beads.analysis.segmenters.ShortFrameSegmenter;
import net.beadsproject.beads.core.AudioContext;
import net.beadsproject.beads.core.AudioIO;
import net.beadsproject.beads.core.UGen;
import net.beadsproject.beads.ugens.Gain;
import processing.core.PApplet;


public class BeadsJNA extends PApplet {

    AudioContext ac;
    ShortFrameSegmenter sfs;
    PowerSpectrum ps;

    public void setup(){
        //defining audio context with 6 inputs and 6 outputs - adjust this based on your sound card / JACK setup
        ac = new AudioContext(new AudioServerIO.Jack(),512,AudioContext.defaultAudioFormat(6,6));

        //getting 4 audio inputs (channels 1,2,3,4)
        UGen microphoneIn = ac.getAudioInput(new int[]{1,2,3,4});
        Gain g = new Gain(ac, 1, 0.5f);
        g.addInput(microphoneIn);
        ac.out.addInput(g);

        println("no. of inputs:  " + ac.getAudioInput().getOuts()); 

        //test get some FFT power spectrum data form the 
        sfs = new ShortFrameSegmenter(ac);
        sfs.addInput(ac.out);
        FFT fft = new FFT();
        sfs.addListener(fft);
        ps = new PowerSpectrum();
        fft.addListener(ps);
        ac.out.addDependent(sfs);

        ac.start();
    }
    public void draw(){
        background(255);
        float[] features = ps.getFeatures();
        if(features != null){
            for(int x = 0; x < width; x++){
              int featureIndex = (x * features.length) / width;
              int barHeight = Math.min((int)(features[featureIndex] *
                                                height), height - 1);
              line(x, height, x, height - barHeight);
            } 
        }
    }

    public static void main(String[] args) {
        PApplet.main(BeadsJNA.class.getSimpleName());
    }

}