This is a utility script that extends the Web Audio API context with a number of common synth and DSP nodes. So far this consists of:
- White noise generator
- Envelope generator
- Feedback delay
- Reverb
- Drum sounds
- Looping sequencer
This is a work in progress.
Note: Requires a browser that supports the webkit Web Audio API (see: http://caniuse.com/audio-api).
A square wave "ping" with delay.
var context = new webkitAudioContext();
//square wave at 440 Hz (default)
var osc = context.createOscillator();
osc.type = osc.SQUARE;
//envelope with 0.001 sec attack and 0.5 sec decay
var envelope = context.createEnvelope(0.001, 0.5, 0, 0);
//feedback delay of 0.4 seconds with 0.5x feedback
var feedbackDelay = context.createFeedbackDelay(0.4, 0.5);
osc.connect(envelope);
envelope.connect(feedbackDelay);
envelope.connect(context.destination);
feedbackDelay.connect(context.destination);
//trigger the note and release after 0.6 seconds
envelope.trigger(0.6);
###Synths###
context.createNoiseGen([stereo [, bufferSize]]) - White noise generator
###Envelope###
context.createEnvelope(a, d, s, r)
Properties
- this.att
- this.dec
- this.sus
- this.rel
Methods
- trigger([length]) - Triggers a note. If length is supplied, the note will automatically be released after length seconds.
- release() - Releases the currently triggered note.
###Instruments###
context.createDrum() context.createHiHat()
Methods
- trigger
###Effects###
context.createFeedbackDelay(delay, feedback)
- delay is in seconds
- feedback is a value between 0 and 1.0
context.createReverbNode(length[, options])
- length is in seconds
Currently available keys for reverb options object:
- decay - how rapidly the sound decays (1 = linear decay, higher numbers are faster exponential decays) - defaults to 2
- reverse - pass in
truefor reverse reverb
###Looping###
Loop Class
Methods
- setInstruments
- setSequences
- setBPM
- setBeatUnit
- startLoop
- stopLoop
More detailed docs to come, for now check out example.html for an example of using the Loop class