Play a random audio file / invoke a function on a random object of a class

Core Library Questions

booyah871

Play a random audio file / invoke a function on a random object of a class

in Core Library Questions • 2 years ago

Hello, My goal is to play a random audio file using the trigger function. If I call a.trigger() file a is played but if I would like to call a random file between (a - z) how would i do that ? I have do it this way :

String[] audio = { "a", "b", "c" };
int index = int(random(audio.length));
audio[index].trigger();

But the following error is returned : The function trigger() does not exist.

Below is the rest of my code and I am using analog inputs running on the Arduino in the Arduino environment to trigger this sketch in processing.

import processing.serial.*;
import ddf.minim.*;

AudioSample a;
AudioSample b;
AudioSample c;

Minim minim;
int linefeed = 10;
Serial myPort;
int sensorValue = 0;

void setup()
{
println(Serial.list());
myPort = new Serial(this, Serial.list()[1], 9600);
minim = new Minim(this);
a = minim.loadSample("yes.wav", 2048);
b = minim.loadSample("no.wav", 2048);
c = minim.loadSample("maybe.wav", 2048);
}

void draw()
{
String[] audio = { "a", "b", "c" };
int index = int(random(audio.length));
stroke(255);

while (myPort.available() > 0)
   {
    String inBuffer = myPort.readString();
    sensorValue = int(trim(inBuffer));
    println(sensorValue);
                if (sensorValue != 0 )
                 {
                   audio[index].trigger();
                   sensorValue=0;
                 }
   }
}

Thanks for your help!

Replies(8)

PhiLho

Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

No wonder, trigger() doesn't exist for strings... You cannot refer to a variable with a string (at least in "regular" coding). Put your audio samples in an array, instead.

booyah871

Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

Thank you for your reply.
It makes sense that the trigger() doesn't exist for strings. I have to make an array of objects and then randomly trigger any of those objects.
I have written it but will try it when I get home, I hope it works and thanks for your input phi.Iho!

import processing.serial.*;
import ddf.minim.*;

AudioSample[] samples = new AudioSample[5];

Minim minim;
int linefeed = 10;
Serial myPort;
int sensorValue = 0;

void setup()
{
println(Serial.list());
myPort = new Serial(this, Serial.list()[1], 9600);
minim = new Minim(this);
samples[0] = minim.loadSample("yes.wav", 2048);
samples[1] = minim.loadSample("no.wav", 2048);
samples[2] = minim.loadSample("maybe.wav", 2048);
}

void draw()
{
int index = int(random(samples.length));
stroke(255);

while (myPort.available() > 0)
   {
    String inBuffer = myPort.readString();
    sensorValue = int(trim(inBuffer));
    println(sensorValue);
                if (sensorValue != 0 )
                 {
                   samples[index].trigger();
                   sensorValue=0;
                 }
   }
}

booyah871

Re: Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

Hello,

I tried to fix the above issue and run the above script but I end up with a NullPointerException and Processing highlights the first line of loading the sample file: samples[0] = minim.loadSample("yes.wav", 2048);

Any help would be appreciated

un_bsd

Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

well your list you say:

AudioSample[] samples = new AudioSample[5];

then declaring the elements of your list you say:

samples[0] = minim.loadSample("yes.wav", 2048);
samples[1] = minim.loadSample("no.wav", 2048);
samples[2] = minim.loadSample("maybe.wav", 2048);

I could convince you I'm a processing guru by telling you that you've only declared three elements in your array yet you set your array size to 5.

PhiLho

Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

As said: if the random number is 3 or 4, you are in trouble...

Be conservative for the length of your array.

booyah871

Re: Play a random audio file / invoke a function on a random object of a class

2 years ago

Hi,

Right - the array size was something i was constantly changing but I should have been more careful to post that. It turns out some of the audio files I was playing were longer than the duration being polled for thats why processing kept crashing.
Also - int index was declared inside the draw() loop which is bad because this variable gets initialized in memory each time the draw() loop is run.

Thanks for your help and this is what I ended up doing :

import ddf.minim.*;
import processing.serial.*;

Minim minim;
AudioSample[] kick = new AudioSample[3];
int linefeed = 10;
Serial myPort;
int sensorValue = 0;

void setup()
{
println(Serial.list());
myPort = new Serial(this, Serial.list()[1], 57600);
minim = new Minim(this);

kick[0] = minim.loadSample("q.WAV", 2048);
kick[1] = minim.loadSample("w.wav", 2048);
kick[2] = minim.loadSample("e.wav", 2048);

}

int index = 0 ;
String inBuffer;

void draw()
{
   index = int(random(kick.length));
   while (myPort.available() > 0)
   {
    inBuffer = myPort.readString();
    sensorValue = int(trim(inBuffer));
    //println(sensorValue);
                if (sensorValue > 100 )
                 {
                   kick[index].trigger();

                   delay(5000);

                 }

   }
}

Nick

Re: Play a random audio file / invoke a function on a random object of a class

2 months ago

Hi, I am a total newbie and have tried a few ways (//as you can see) to get these random files to play back when mousePressed but to no avail. This is the closest post I have found to what I am trying to do, which is to trigger the files, display the filename at the location and change the background to a random colour. Can anyone tell me what I am doing wrong?

Minim minim;
AudioSample[]notes = new AudioSample[8];
AudioMetaData meta;
int myRan;
void setup() {
size(400, 680);
background(0);
colorMode(HSB);
textFont(createFont("Serif", 12));
minim = new Minim(this);
notes[0] = minim.loadSample("A2 MONO.wav", 2048);
notes[1] = minim.loadSample("B2.wav", 2048);
notes[2] = minim.loadSample("C2.wav", 2048);
notes[3] = minim.loadSample("D2.wav", 2048);
notes[4] = minim.loadSample("E2.wav", 2048);
notes[5] = minim.loadSample("F2.wav", 2048);
notes[6] = minim.loadSample("G2.wav", 2048);
notes[7] = minim.loadSample("C3.wav", 2048);
}
int index = 0;
void draw() {
if (mousePressed)
{
//index = int(random(notes.length));
background(random(255), 255, 255);
myRan = (int) random(0, 8);
notes[myRan].play();
notes[myRan].cue(0);
fill(255);
textSize(random(48, 400));
text("" + meta.fileName(), mouseX, mouseY);
}
}
void stop() {
minim.stop();
super.stop();
}

Nick

Re: Re: Play a random audio file / invoke a function on a random object of a class

2 months ago

By the way, I have a MacBook Pro on Snow leopard with Processing 2.01 and am working in Javascript mode if that helps. I have also got the minim api in another tab. When I run the sketch I just get a black background, nothing plays or changes when I press the mouse.

Ay help would be great as I really struggling to understand this and have tried several methods already.

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