NOTE: This is a fork from https://github.com/corbanbrook/dsp.js.git, just making it available on NPMJS.

                              DSP.js

DSP.js is a comprehensive digital signal processing library for javascript. It includes many functions for signal analysis and generation, including Oscillators(sine, saw, square, triangle), Window functions (Hann, Hamming, etc), Envelopes(ADSR), IIR Filters(lowpass, highpass, bandpass, notch), FFT and DFT transforms, Delays, Reverb.

Modules:

DFT(bufferSize, sampleRate): Discrete Fourier Transform

Usage: 

var dft = new DFT(1024, 44100);
dft.forward(signal);
var spectrum = dft.spectrum;

FFT(bufferSize, sampleRate): Fast Fourier Transform

Usage:

var fft = new FFT(2048, 44100);
fft.forward(signal);
var spectrum = fft.spectrum;

Oscillator(waveform, frequency, amplitude, bufferSize, sampleRate): Signal Generator * Sine wave * Square wave * Saw wave * Triangle wave

Usage:

var osc = new Oscillator(SINEWAVE, 440, 1, 2048, 22050);
osc.generate();
var signal = osc.signal;

ADSR(attack, decay, sustainLevel, sustain, release, sampleRate): Attack-Decay-Sustain-Release Envelope

Usage:

var envelope = new ADSR(0.01, 0.1, 0.5, 0.1, 0.2, 44100);
envelope.process(signal);

IIRFilter(filter, cutoff, sampleRate): Infinite Impulse Response Filters * Low Pass Filter * High Pass Filter

Usage:

var filter = IIRFilter(LOWPASS, 200, 44100);
filter.process(signal);

MultiDelay(maxDelayInSamplesSize, delayInSamples, masterVolume, delayVolume): Delay which feeds back its own delayed signal

Usage:

var delay = MultiDelay(44100*5, 44100*1, 1.0, 0.6);
delay.process(signal);  

Reverb(maxDelayInSamplesSize, delayInSamples, masterVolume, mixVolume, delayVolume, dampFrequency): Reverb

Usage:

var reverb = Reverb(20000, 6500, 0.8, 0.5, 0.9, 4500);
reverb.process(signal); 

@corban

   Copyright (c) 2010 Corban Brook, released under the MIT license