moust · June 24, 2015 14:53
diff --git a/spectrogram.html b/spectrogram.html
 <!doctype html>
 <html>
    <head>
        <meta charset="utf-8" />
        <title>Spectrogram</title>
        <style type="text/css">
            .visualizer {
                display: block;
                background-color: black;
            }
        </style>
    </head>
    <body>

        <canvas class="visualizer" width="800" height="512"></canvas>

        <canvas class="wavelet" width="800" height="512"></canvas>

        <script type="text/javascript" src="bower_components/dat-gui/build/dat.gui.min.js"></script>
        <script type="text/javascript" src="bower_components/chroma-js/chroma.js"></script>
        <script type="text/javascript">

            var canvas = document.querySelector('.visualizer');
            var canvasCtx = canvas.getContext("2d");

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

            var javascriptNode = audioCtx.createScriptProcessor(2048, 1, 1);
            javascriptNode.connect(audioCtx.destination);

            var analyser = audioCtx.createAnalyser();
            // analyser.minDecibels = -90;
            // analyser.maxDecibels = -10;
            // analyser.smoothingTimeConstant = 0.85;
            analyser.smoothingTimeConstant = 0;
            analyser.fftSize = 1024;
            analyser.connect(javascriptNode);

            var source = audioCtx.createBufferSource();
            source.connect(analyser);
            source.connect(audioCtx.destination);

            // var track = 'Beautiful Lies.mp3';
            var track = 'paradise_circus.mp3';
            // var track = 'Aphex Twin - Window Licker.mp3';

            var request = new XMLHttpRequest();
            request.open('get', track, true);
            request.responseType = 'arraybuffer';
            request.onload = function () {
                audioCtx.decodeAudioData(request.response, function (buffer) {
                    source.buffer = buffer;
                    source.start(0);
                });
            };
            request.send();


            javascriptNode.onaudioprocess = function () {
                var array = new Uint8Array(analyser.frequencyBinCount);
                analyser.getByteFrequencyData(array);
                drawSpectrogram(array);
            };

            var tempCanvas = document.createElement("canvas"),
                tempCtx = tempCanvas.getContext("2d");
            tempCanvas.width = canvas.width;
            tempCanvas.height = canvas.height;

            var getColor = chroma.scale(['#000000', '#ff0000', '#ffff00', '#ffffff'], [0, .25, .75, 1]).domain([0, 300]);

            function drawSpectrogram (array) {
                // copy the current canvas onto the temp canvas
                tempCtx.drawImage(canvas, 0, 0, canvas.width, canvas.height);

                for(var i = 0; i < array.length; i++) {
                    // var magnitude = Math.log(Math.abs(array[i])+1);
                    // canvasCtx.fillStyle = 'rgb(' + Math.round(magnitude*40) + ', ' + Math.round(magnitude*5) + ', 0)';
                    canvasCtx.fillStyle = getColor(array[i]).hex();
                    canvasCtx.fillRect(canvas.width - 1, canvas.height - i, 1, 1);
                }

                // var landmarks = getLandmarks(array);
                // for (var i = 0; i < landmarks.length; i++) {
                //  canvasCtx.fillStyle = 'rgb(100, 200, 255)';
                //  canvasCtx.fillRect(canvas.width - 1, canvas.height - landmarks[i], 1, 1);
                // };

                // set translate on the canvas
                canvasCtx.translate(-1, 0);
                // draw the copied image
                canvasCtx.drawImage(tempCanvas, 0, 0, canvas.width, canvas.height, 0, 0, canvas.width, canvas.height);

                // reset the transformation matrix
                canvasCtx.setTransform(1, 0, 0, 1, 0, 0);
            }


            function getLandmarks (array) {
                var recordPoints = [0,0,0,0,0];
                var highscores = [0,0,0,0,0];
                for(var i = 0; i < array.length; i++) {
                    var magnitude = Math.log(Math.abs(array[i]) + 1);
                    var index = getIndex(array[i]);
                    if (magnitude > highscores[index]) {
                        highscores[index] = magnitude;
                        recordPoints[index] = array[i];
                    }
                }
                return recordPoints;
            }

            var RANGE = [40,80,120,180,300];

            function getIndex (value) {
                var i = 0;
                while(RANGE[i] < value) i++;
                return i;
            }


            var gui = new dat.GUI();

            var f1 = gui.addFolder('Analyser');
            f1.open();
            f1.add(analyser, 'minDecibels', -100, 0);
            f1.add(analyser, 'maxDecibels', -100, 0);
            f1.add(analyser, 'smoothingTimeConstant', 0, 1).step(0.01);
            f1.add(analyser, 'fftSize', [32,64,128,256,512,1024,2048]);

        </script>

    </body>
 </html>
	<!doctype html>
	<html>
	<head>
	<meta charset="utf-8" />
	<title>Spectrogram</title>
	<style type="text/css">
	.visualizer {
	display: block;
	background-color: black;
	}
	</style>
	</head>
	<body>

	<canvas class="visualizer" width="800" height="512"></canvas>

	<canvas class="wavelet" width="800" height="512"></canvas>

	<script type="text/javascript" src="bower_components/dat-gui/build/dat.gui.min.js"></script>
	<script type="text/javascript" src="bower_components/chroma-js/chroma.js"></script>
	<script type="text/javascript">

	var canvas = document.querySelector('.visualizer');
	var canvasCtx = canvas.getContext("2d");

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

	var javascriptNode = audioCtx.createScriptProcessor(2048, 1, 1);
	javascriptNode.connect(audioCtx.destination);

	var analyser = audioCtx.createAnalyser();
	// analyser.minDecibels = -90;
	// analyser.maxDecibels = -10;
	// analyser.smoothingTimeConstant = 0.85;
	analyser.smoothingTimeConstant = 0;
	analyser.fftSize = 1024;
	analyser.connect(javascriptNode);

	var source = audioCtx.createBufferSource();
	source.connect(analyser);
	source.connect(audioCtx.destination);

	// var track = 'Beautiful Lies.mp3';
	var track = 'paradise_circus.mp3';
	// var track = 'Aphex Twin - Window Licker.mp3';

	var request = new XMLHttpRequest();
	request.open('get', track, true);
	request.responseType = 'arraybuffer';
	request.onload = function () {
	audioCtx.decodeAudioData(request.response, function (buffer) {
	source.buffer = buffer;
	source.start(0);
	});
	};
	request.send();


	javascriptNode.onaudioprocess = function () {
	var array = new Uint8Array(analyser.frequencyBinCount);
	analyser.getByteFrequencyData(array);
	drawSpectrogram(array);
	};

	var tempCanvas = document.createElement("canvas"),
	tempCtx = tempCanvas.getContext("2d");
	tempCanvas.width = canvas.width;
	tempCanvas.height = canvas.height;

	var getColor = chroma.scale(['#000000', '#ff0000', '#ffff00', '#ffffff'], [0, .25, .75, 1]).domain([0, 300]);

	function drawSpectrogram (array) {
	// copy the current canvas onto the temp canvas
	tempCtx.drawImage(canvas, 0, 0, canvas.width, canvas.height);

	for(var i = 0; i < array.length; i++) {
	// var magnitude = Math.log(Math.abs(array[i])+1);
	// canvasCtx.fillStyle = 'rgb(' + Math.round(magnitude40) + ', ' + Math.round(magnitude5) + ', 0)';
	canvasCtx.fillStyle = getColor(array[i]).hex();
	canvasCtx.fillRect(canvas.width - 1, canvas.height - i, 1, 1);
	}

	// var landmarks = getLandmarks(array);
	// for (var i = 0; i < landmarks.length; i++) {
	// canvasCtx.fillStyle = 'rgb(100, 200, 255)';
	// canvasCtx.fillRect(canvas.width - 1, canvas.height - landmarks[i], 1, 1);
	// };

	// set translate on the canvas
	canvasCtx.translate(-1, 0);
	// draw the copied image
	canvasCtx.drawImage(tempCanvas, 0, 0, canvas.width, canvas.height, 0, 0, canvas.width, canvas.height);

	// reset the transformation matrix
	canvasCtx.setTransform(1, 0, 0, 1, 0, 0);
	}


	function getLandmarks (array) {
	var recordPoints = [0,0,0,0,0];
	var highscores = [0,0,0,0,0];
	for(var i = 0; i < array.length; i++) {
	var magnitude = Math.log(Math.abs(array[i]) + 1);
	var index = getIndex(array[i]);
	if (magnitude > highscores[index]) {
	highscores[index] = magnitude;
	recordPoints[index] = array[i];
	}
	}
	return recordPoints;
	}

	var RANGE = [40,80,120,180,300];

	function getIndex (value) {
	var i = 0;
	while(RANGE[i] < value) i++;
	return i;
	}


	var gui = new dat.GUI();

	var f1 = gui.addFolder('Analyser');
	f1.open();
	f1.add(analyser, 'minDecibels', -100, 0);
	f1.add(analyser, 'maxDecibels', -100, 0);
	f1.add(analyser, 'smoothingTimeConstant', 0, 1).step(0.01);
	f1.add(analyser, 'fftSize', [32,64,128,256,512,1024,2048]);

	</script>

	</body>
	</html>