How to play a couple of milliseconds of an audio file?

Core Library Questions

danielle_..

How to play a couple of milliseconds of an audio file?

in Core Library Questions • 4 months ago

Hi all,

I'm new to the minim library. I've been searching the web and this forum but I can't find an answer to my problem:
Say I have an mp3 file of a 3 minutes. I want to play random 10 milliseconds part of that file every second. How do I approach this problem? So far I've only found how to play an entire song from setup()
Do I use a buffer of is AudioSample the way to go? Eventually I want to use a lengthy track, up to 60 minutes to grab parts from and play them.

Any help would be greatly appreciated. TIA, danielle.

Replies(4)

lasnzl

Re: How to play a couple of milliseconds of an audio file?

4 months ago

Try using an AudioPlayer. Cue to your start point and use the looping methods to play 10 ms (I believe you set it to loop 0 times to play once); alternatively, you can poll the position and pause when you've played 10 ms.

If you need access to the samples for some kind of analysis, use an AudioRecordingStream, from the spi package. Some of the method names are different, but you have the same control that an AudioPlayer gives you.

danielle_..

Re: How to play a couple of milliseconds of an audio file?

4 months ago

Hi lasnzl,
Thanks very much for your tips. I was getting there just a your answer arrived. This is the working code, for those interested:

void setup()
{
size(100, 100);

minim = new Minim(this);

song = minim.loadFile("Harlem-Shake.mp3");
trackLength = song.length();
lastTime = millis();
}

void draw()
{
background(0);
if(millis() - lastTime >= 1000-tick){
    int cue = int(createCue());
    song.setLoopPoints(cue, cue+tick);
    song.loop(0);
    lastTime = millis();
}
}

float createCue()
{
return random(0, trackLength-tick);
}

void stop()
{
song.close();
minim.stop();
super.stop();

I works great with a .wav file but mp3's generate all kinds of errors:

==== JavaSound Minim Error ====
==== Don't know the ID3 code RVAD

==== JavaSound Minim Error ====
==== Don't know the ID3 code TBPM

==== JavaSound Minim Error ====
==== Don't know the ID3 code GEOB

==== JavaSound Minim Error ====
==== Don't know the ID3 code APIC

Any idea what this means and how I can solve it? TIA, d

tfguy44

Re: How to play a couple of milliseconds of an audio file?

4 months ago

Those error are just things that the mp3 file knows about itself that Minim can't deal with.

Specifically, your mp3 has reverb, an indication of its beats per minute, the fact that it's a general encapsulate object, and that it has an associate picture.
So long as your mp3 plays fine, these "errors" are nothing to worry about.

danielle_..

Re: How to play a couple of milliseconds of an audio file?

4 months ago

Hi tfguy44,

The track plays fine when I just do song.play(). But it doesn't work with my application of which the code is above. It only plays a snippet every now and again and not every second. If I'd created a new mp3 what would I need to keep in mind to avoid the errors and problems?

Thanks very much in advance, d

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