crossfade

Simple cross fader between two AudioNodes for WebAudio.

Usage

npm install crossfader

var crossfader = require('crossfader');
var c = crossfader(context, node1, node2);
c.connect(context.destination);

document.getElementById('slider').addEventListener('input', function(){
	c.fade.value = parseFloat(this.value);
});

API

Constructor

eg : var c = crossfader(context, node1, node2);

• context: AudioContext - The AudioContext within which the AudioNodes have been created.
• node1 : AudioNode - Any AudioNode within the AudioContext. Will be assigned to the negative value of the fade property.
• node2 : AudioNode - Any AudioNode within the AudioContext. Will be assigned to the negative value of the fade property.

Methods

• connect : Connect the crossfade Node to other AudioNodes. eg :

  c.connect(context.destination);
  

  • arguments :
    • destination : AudioNode - The AudioNode to connect the output of the crossfader to.

• disconnect : Disconnect the crossfade Node from other AudioNodes. eg :

  c.disconnect();
  

  • supports the same arguments as disconnect method on AudioNodes

Properties

• fade: AudioParam - A value in the range [-1,1] that defines how much to cross fade between node1 and node2.

  eg:

  c.fade.value = 0.5; //Cross fade position with equal volume from both AudioNodes
  c.fade.linearRampToValueAtTime(1, context.currentTime + 5); // Automation
  

  fade property is an AudioParam and supports all AudioParam automation methods.

  • A fade value of -1 implies 100% volume on node1, and 0% volume on node2, while a fade value of 1 implies 0% volume on node1, and 100% volume on node2.

  • The mapping between the value of fade and the volume follows the equal power curve.

Credits

Thanks to tambien for the his idea of using a generator + shaper to create a-rate, first class, custom AudioParams (like fade in this case).

License

MIT

See License file