audio.io (v0.1.0)

A (possibly overkill) web audio and MIDI helper library. Allows for things like this:

// Create AudioContext and destination (audio.io.masterOut)
audio.io.initialize();

// Create the master volume control and connect its output
// "port" to the destination node.
var volume = (new audio.io.VolumeControl( 'x*x', 50 )).connectTo(audio.io.masterOut);

// Attempt to do the MIDI dance on channel 1,
// with no event debugging.
var midi = new audio.io.MIDI( 1, false );

// Create a panpot...
var panpot = new audio.io.PanPot(0);

// ..and connect it to master out
panpot.connectTo(volume);

// Listen to the `pitchbend` event from the MIDI node and scale the
// input (0-127) to the panpot's accepted value range of -50 to 50.
midi.events.on('pitchbend', function(channel, something, value) {
    panpot.setPosition( audio.io.utils.scaleNumber(value, 0, 127, -50, 50) );
});

// Create a playable oscillator (not single-shot) and
// allow it to have up to 16 voices, using a sine wave,
// and set the retriggering argument to true, and
// volumeControl curve to x*x
var playableOsc = new audio.io.Oscillator( 'sine', 16, true, 'x*x' );
playableOsc.connectTo(panpot);

midi.events.on('noteOn', function(channel, freq, velocity) {
    if(velocity === 0) {
        playableOsc.stop( freq );
    }
    else {
        playableOsc.start( freq, velocity );
    }
});

How to

Install the Jazz-Soft Jazz-Plugin: http://jazz-soft.net/

git clone git@github.com:squarefeet/audio.io.git

Open ./audio.io/testbed/index.html in a WebAudio-compatible browser with a MIDI input device connected.