| license: mit |
This listens to your computer's microphone and draws the contents of the audio buffer as a radial line. Also made a bright version: Audio Radial Line - bright
This is part of a series exploring the visualization of audio that was presented at a d3.oakland meetup. A big list of the demos from this series can be found here.
| <!DOCTYPE html> | |
| <title>Radial Line - Dark</title> | |
| <script src="//d3js.org/d3.v4.min.js"></script> | |
| <body style="margin: 0px"> | |
| <canvas></canvas> | |
| </body> | |
| <script> | |
| const width = innerWidth; | |
| const height = innerHeight; | |
| const audioCtx = new (window.AudioContext || window.webkitAudioContext)(); | |
| const analyser = audioCtx.createAnalyser(); | |
| const dataArray = new Uint8Array(analyser.fftSize); | |
| const drawLength = dataArray.length/2; | |
| let drawArray = []; | |
| const canvas = document.querySelector('canvas'); | |
| canvas.setAttribute('width',width); | |
| canvas.setAttribute('height',height); | |
| const canvasCtx = canvas.getContext("2d"); | |
| canvasCtx.fillStyle = 'rgba(0, 0, 0, 1)'; | |
| canvasCtx.strokeStyle = 'rgb(255, 0, 0)'; | |
| canvasCtx.lineWidth = 1; | |
| canvasCtx.translate(width/2, height/2); | |
| navigator.getUserMedia ( | |
| {audio: true}, | |
| function(stream) { | |
| audioCtx.createMediaStreamSource(stream).connect(analyser); | |
| draw(); | |
| }, | |
| function(err) { | |
| console.log('The following gUM error occured: ' + err); | |
| } | |
| ); | |
| const radialLine = d3.radialLine() | |
| .curve(d3.curveBasis) | |
| .angle(function(d, i) { | |
| return i / (drawLength / 2) * Math.PI * 2 | |
| }) | |
| .radius(function(d, i) { | |
| return Math.abs(drawArray[i] - 128) / 128 * Math.min(height, width/2) | |
| }) | |
| .context(canvasCtx); | |
| function draw() { | |
| canvasCtx.fillRect(-width/2, -height/2, width, height); | |
| analyser.getByteTimeDomainData(dataArray); | |
| drawArray = [...Array.from(dataArray), ...drawArray].slice(0, drawLength); | |
| canvasCtx.beginPath(); | |
| radialLine(drawArray); | |
| canvasCtx.stroke(); | |
| requestAnimationFrame(draw); | |
| }; | |
| </script> |
