function PitchShiftNode(context, shiftOffset, options) {
var queue = [];
options = options || {};
options.frameSize = options.frameSize || 512;
options.hopSize = options.hopSize || options.frameSize / 4;
var shifter = pitchShift(onData, onTune, options);
var scriptNode = context.createScriptProcessor(options.frameSize, 1, 1);
scriptNode.onaudioprocess = function(e) {
shift(e.inputBuffer.getChannelData(0));
var out = e.outputBuffer.getChannelData(0);
var q = queue[0];
queue.shift();
out.set(q);
pool.freeFloat32(q);
};
scriptNode.shiftOffset = shiftOffset;
//Enque some garbage to buffer stuff
shift(new Float32Array(options.frameSize));
shift(new Float32Array(options.frameSize));
shift(new Float32Array(options.frameSize));
shift(new Float32Array(options.frameSize));
shift(new Float32Array(options.frameSize));
return scriptNode;
function shift(frame) {
shifter(frame);
}
function onData(data) {
var buf = pool.mallocFloat32(data.length);
buf.set(data);
queue.push(buf);
}
function onTune(t, pitch) {
return scriptNode.shiftOffset;
}
}
function createProcessingNode(context) {
var queue = []
var frame_size = 1024
var hop_size = 256
var shifter = pitchShift(function(data) {
var buf = pool.mallocFloat32(data.length)
buf.set(data)
queue.push(buf)
}, function(t, pitch) {
console.log(t, pitch)
return 0.1 * (Math.round(t) % 15) + 0.5
}, {
frameSize: frame_size,
hopSize: hop_size
})
//Enque some garbage to buffer stuff
shifter(new Float32Array(frame_size))
shifter(new Float32Array(frame_size))
shifter(new Float32Array(frame_size))
shifter(new Float32Array(frame_size))
shifter(new Float32Array(frame_size))
//Create a script node
var scriptNode = context.createScriptProcessor(frame_size, 1, 1)
scriptNode.onaudioprocess = function(e){
shifter(e.inputBuffer.getChannelData(0))
var out = e.outputBuffer.getChannelData(0)
var q = queue[0]
queue.shift()
out.set(q)
pool.freeFloat32(q)
}
return scriptNode
}