Useful Console Code Thread

[Jacob_]

Code:

loadInstrument(13);
var el = $('<input type="file" accept="audio/*">');
$(document.body).append(el);

el.on('change', function(e){
    var reader = new FileReader();
    reader.onload = function (e) {
        var context = new AudioContext();
        context.decodeAudioData(e.target.result, function(buffer){
            var node = context.createAnalyser();
            // node.connect(context.destination);
            var resolution = 4;
            node.fftSize = 4096;
            node.smoothingTimeConstant = 0;
            var bufferLength = node.frequencyBinCount;
            var dataArray = new Uint8Array(bufferLength);
            var audioSource = context.createBufferSource();
            audioSource.buffer = buffer;
            audioSource.loop = false;
            audioSource.connect(node);
            var time = 0;
            audioSource.start(0);  
            setInterval(function(){
                node.getByteFrequencyData(dataArray);
                var f = [];
                for (var i = 1; i < dataArray.length - 1; i++) {
                  var isPeak = dataArray[i] >= dataArray[i-1] && dataArray[i] >= dataArray[i+1];
                  if (isPeak) {
                    f.push([i, dataArray[i]]);
                  }
                }
                f.sort(function(a, b){return b[1] - a[1]});
                var added = 0;
                var i = 0;
                while (added < 4) {
                  if (i >= f.length) break;
                  var frequency = f[i][0] * context.sampleRate / node.fftSize;
                  var note = piano[Math.round((piano.length*Math.log(2)+12*Math.log(55/frequency)+Math.log(4))/(Math.log(2)))];
                  if (note != undefined && f[i][1] > 32) {
                    song.addNote(new Note(song, note, time/resolution, 1/resolution, 13));
                    added++;
                  }
                  i++;
                }
                time++;
            }, song.sleepTime/resolution);
            setInterval(SequencerView.repaint, 1000);
        });
    }
    
    reader.readAsArrayBuffer(e.target.files[0]);
});

el.click();