source: main/trunk/model-sites-dev/respooled/collect/popup-video-respooled/js/in-the-groove.js@ 29867

// https://developer.mozilla.org/en-US/docs/Web/API/AudioContext/createScriptProcessor

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();

var InTheGroove = false;
var MissingTheGroovePending = false;

//var bufferSize = 4096;
var bufferSize = 512;


//window.addEventListener('load', onLoad, false);


var prev_input = [0,0];

$(document).ready(function() {
    $('#video').on('loadedmetadata', function() {

    displayDuration(this.duration); 

    // Create a MediaElementAudioSourceNode
    // Feed the HTMLMediaElement into it
    var source = audioCtx.createMediaElementSource(this);
    
    // connect the AudioBufferSourceNode to the tinnyEffectNode
    // and the tinnyEffectNode to the destination, so we can play the
    // music and have the filter 'kick in' when 'Missing Out' button 
    // pressed

    var tinnyEffectNode = audioCtx.createScriptProcessor(bufferSize, 2, 2);
    tinnyEffectNode.onaudioprocess = function(e) {

        for (var c = 0; c<2; c++) {
        var input = e.inputBuffer.getChannelData(c);
        var output = e.outputBuffer.getChannelData(c);
        
        
        for (var i = 0; i < bufferSize; i++) {
            if (InTheGroove) {
            if (c==0) {
                output[i] = input[i];
            }
            else {
                output[i] = 0;
            }
            }
            else {
            // Make sound 'tinny' through simple high-pass filter
            output[i] = input[i] - prev_input[c];
            }
            prev_input[c] = input[i];
        }
        }
    }
        
    source.connect(tinnyEffectNode); 
    tinnyEffectNode.connect(audioCtx.destination);

    console.log("onLoadMetadata done");
    });

});

function inTheGroove()
{
    InTheGroove = true;
    MissingTheGroovePending = false;
}

function missingTheGroove()
{
    if (MissingTheGroovePending) {
    InTheGroove = false;
    }
    MissingTheGroovePending = false;    
}

function delayedMissingTheGroove(delay)
{
    MissingTheGroovePending = true;
    setTimeout(missingTheGroove,delay || 400);
}