FrequencyAnalyzer

This FrequencyAnalyzer class is used at the Maastricht Institute of Arts exposition during the "Generative Art" semester. Students create sketches that react in realtime to audio input (line-in, audio file or microphone).

This library adds functionality like:

• easily switch between input modes (audio file, microphone, line-in)
• toggle mute (audio file playing) or monitoring (microphone or line-in)

todo:

• return raw or normalized values of specific frequency bands
• reset the max value that is used for mapping normalized values of frequency amplitudes. Can be set to an interval.

Usage

// Import the library to your sketch
import nl.genart.VJMotion.frequencyanalyzer.*;

// Import the minim library
import ddf.minim.*;
import ddf.minim.analysis.*;

Minim minim;
FrequencyAnalyzer fa;

void setup() {
  size(500, 500);

  minim = new Minim(this);
  fa = new FrequencyAnalyzer(this)
    .addMinim(minim)
    .setFile("https://github.com/vincentsijben/vjmotion-processing/raw/main/assets/infraction_music_-_ritmo.mp3")
    .setAudioInputMode(AudioInputMode.AUDIO_FILE)
    ;
}

void draw() {
  background(50);

  circle(width/4*1, height/2, fa.getVolume(0));
  circle(width/4*2, height/2, fa.getVolume(10));
  circle(width/4*3, height/2, fa.getVolume(20));
  circle(width/4*2, height/4*3, fa.getVolume()); // averaged overall volume
}

Setup

You can tweak the behaviour of this library with the following functions (you can also chain them when initializing your frequencyanalyzer object for clarity):

• .addMinim(minim) mandatory to add the global minim object to the class.
• .setFile("example.mp3") to set the file for the audioplayer. Defaults to "https://github.com/vincentsijben/vjmotion-processing/raw/main/assets/infraction_music_-_ritmo.mp3"
• .setAudioInputMode(AudioInputMode.AUDIO_FILE) to set the input mode to AudioInputMode.AUDIO_FILE. You can also set it to AudioInputMode.LINE_IN or AudioInputMode.MICROPHONE. Defaults to AudioInputMode.MICROPHONE.
• .setAudioInputMode(AudioInputMode.AUDIO_FILE, n) same as previous one, but you can also set the bufferSize. Needs to be a power of 2. A lower amount results in less audio resolution and decreases delay . Defaults to 1024.
• .setAudioOutputMode(AudioOutputMode.STEREO) to set the output mode to AudioOutputMode.STEREO. Defaults to AudioOutputMode.MONO. Use it to get access to both left and right channel analysis.
• .showInfoPanel() to show the infopanel.
• .setInfoPanelY(n) to offset the starting y-position of the infopanel by n pixels. Useful for when you have multiple infopanels to get them all lined up.
• .setInfoPanelKey('u') to change the hotkey to toggle the infopanel. Useful for when you have multiple infopanels. Defaults to 'i'.

• .disableKeyPress() to disable listening for keypresses. If you don't disable keypresses, then these keypresses will work:

  • F1 switch to FILE mode
  • F2 switch to MONO mode
  • F3 switch to STEREO mode
  • F4 toggle monitoring on LINE_IN or MICROPHONE input

Functions

The FrequencyAnalyzer class provides the following main functions:

• getVolume() returns the normalized averaged amplitude for all frequencies combined.

• getVolume(20) returns normalized amplitude for frequency band 20. The (zero-based) index ranges from 0 to logAverages(22, 3) which is 30 by default.

• getAvgRaw(1) returns non-normalized "raw" averaged amplitude for frequency band 1. The index ranges from 0 to logAverages(22, 3) which is 30 by default.

  • getAvgRawLeft(1) same as getAvgRaw(1) but specific for the left channel.
  • getAvgRawRight(1) same as getAvgRaw(1) but specific for the right channel.

todo:

• getBand(1) returns the amplitude for frequency band 1. Used for a very specific and narrow frequency range. The index ranges from 0 to specSize().~~

  • getBandLeft(1) same as getBand(1) but specific for the left channel.~~
  • getBandRight(1) same as getBand(1) but specific for the right channel.~~

• specSize() returns the total amount of bands used. Typically 1025 ~~

• avgSize() returns the total amount of bands used in the logAverages function. Typically 30~~

• getAudioBuffer() returns the mixed (mono) audio buffer.~~

  • getLeftChannelBuffer() returns the left audio buffer.~~
  • getRightChannelBuffer() returns the right audio buffer.~~

Examples

You can find all these examples in Processing -> File - Examples - Contributed Libraries - VJMotion - FrequencyAnalyzer.

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