我正在尝试使用我在网上找到的示例对在线广播流使用音频可视化这一页。
然而，与发现的问题类似这个帖子，我的音频文件（即使使用本地文件进行测试）就是没有声音，当然可视化也没有任何作用。
我的 HTML 如下：
<html>
<head>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<audio src="http://50.22.218.101:38838/;steam.mp3" id="audio"
controls>HTML5 Audio element not supported</audio>
<canvas id="canvas" width="800" height="350"></canvas>
<script src="main.js"></script>
</body>
</html>
这是“main.js”：
window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext;
window.onload = function() {
var audio = document.getElementById('audio');
var ctx = new AudioContext();
var analyser = ctx.createAnalyser();
var audioSrc = ctx.createMediaElementSource(audio);
// we have to connect the MediaElementSource with the analyser
audioSrc.connect(analyser);
analyser.connect(ctx.destination);
// we could configure the analyser: e.g. analyser.fftSize (for further infos read the spec)
// analyser.fftSize = 64;
// frequencyBinCount tells you how many values you'll receive from the analyser
var frequencyData = new Uint8Array(analyser.frequencyBinCount);
// we're ready to receive some data!
var canvas = document.getElementById('canvas'),
cwidth = canvas.width,
cheight = canvas.height - 2,
meterWidth = 10, //width of the meters in the spectrum
gap = 2, //gap between meters
capHeight = 2,
capStyle = '#fff',
meterNum = 800 / (10 + 2), //count of the meters
capYPositionArray = []; ////store the vertical position of hte caps for the preivous frame
ctx = canvas.getContext('2d'),
gradient = ctx.createLinearGradient(0, 0, 0, 300);
gradient.addColorStop(1, '#0f0');
gradient.addColorStop(0.5, '#ff0');
gradient.addColorStop(0, '#f00');
// loop
function renderFrame() {
var array = new Uint8Array(analyser.frequencyBinCount);
analyser.getByteFrequencyData(array);
var step = Math.round(array.length / meterNum); //sample limited data from the total array
ctx.clearRect(0, 0, cwidth, cheight);
for (var i = 0; i < meterNum; i++) {
var value = array[i * step];
if (capYPositionArray.length < Math.round(meterNum)) {
capYPositionArray.push(value);
};
ctx.fillStyle = capStyle;
//draw the cap, with transition effect
if (value < capYPositionArray[i]) {
ctx.fillRect(i * 12, cheight - (--capYPositionArray[i]), meterWidth, capHeight);
} else {
ctx.fillRect(i * 12, cheight - value, meterWidth, capHeight);
capYPositionArray[i] = value;
};
ctx.fillStyle = gradient; //set the filllStyle to gradient for a better look
ctx.fillRect(i * 12 /*meterWidth+gap*/ , cheight - value + capHeight, meterWidth, cheight); //the meter
}
requestAnimationFrame(renderFrame);
}
renderFrame();
audio.play();
};
知道我做错了什么吗？
