JS实现可视化音频效果的实例代码
符华- 人气:0效果如图：
背景图片可以换成自己喜欢的或者不用，线条的颜色粗细也可以自己调整。
代码如下（可直接复制使用）：
<html lang="en">
<head>
<meta charset="UTF-8">
<title>可视化音频</title>
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<style> body {
display: block;
background: url("./8.jpg");
background-position: center;
background-repeat: no-repeat;
background-attachment: fixed;
background-size:100%;
}
</style>
</head>
<body>
<input type="file" style="color:red;" name="" value="" id="musicFile"><input type="button" name="startStop" value="暂停" id="startStop">
<p id="tip" style="color:red;"></p>
<canvas id="canvas"></canvas>
<script>
window.onload = function () {
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
var canvasCtx = canvas.getContext("2d");
var AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext;
var audioContext = new AudioContext();//实例化
$('#musicFile').change(function(){
//当选择歌曲时，判断当前audioContext的状态，如果在进行中则关闭音频环境，
//释放audioContext的所有资源，并重新实例化audioContext
if(audioContext.state == 'running'){
audioContext.close();
audioContext = new AudioContext();
}
if (this.files.length == 0) return;
var file = $('#musicFile')[0].files[0];
var fileReader = new FileReader();
fileReader.readAsArrayBuffer(file);
fileReader.onload = function(e) {
var count = 0;
$('#tip').text('开始解码')
var timer = setInterval(function(){
count++;
$('#tip').text('解码中,已用时'+count+'秒')
},1000)
audioContext.decodeAudioData(e.target.result, function(buffer) {
clearInterval(timer)
$('#tip').text('解码成功，用时共计:'+count+'秒')
var audioBufferSourceNode = audioContext.createBufferSource();
var analyser = audioContext.createAnalyser();
analyser.fftSize = 256;
audioBufferSourceNode.connect(analyser);
analyser.connect(audioContext.destination);
audioBufferSourceNode.buffer = buffer;
audioBufferSourceNode.start();
var bufferLength = analyser.frequencyBinCount;
var dataArray = new Uint8Array(bufferLength);
//播放暂停音频
startStop.onclick = function() {
if(audioContext.state === 'running') {
audioContext.suspend().then(function() {
$("#startStop").val('播放');
});
} else if(audioContext.state === 'suspended') {
audioContext.resume().then(function() {
$("#startStop").val('暂停');
});
}
}
var oW = canvas.width;
var oH = canvas.height;
var color1 = canvasCtx.createLinearGradient(oW / 2, oH / 2-10, oW / 2, oH / 2 - 150);
var color2 = canvasCtx.createLinearGradient(oW / 2, oH / 2+10, oW / 2, oH / 2 + 150);
color1.addColorStop(0, '#1E90FF');
color1.addColorStop(.25, '#FF7F50');
color1.addColorStop(.5, '#8A2BE2');
color1.addColorStop(.75, '#4169E1');
color1.addColorStop(1, '#00FFFF');
color2.addColorStop(0, '#1E90FF');
color2.addColorStop(.25, '#FFD700');
color2.addColorStop(.5, '#8A2BE2');
color2.addColorStop(.75, '#4169E1');
color2.addColorStop(1, '#FF0000');
function draw() {
drawVisual = requestAnimationFrame(draw);
var barHeight;
// 自定义获取数组里边数据的频步
canvasCtx.clearRect(0, 0, oW, oH);
for (var i = 0; i < bufferLength; i++) {
barHeight = dataArray[i];
analyser.getByteFrequencyData(dataArray);
// 绘制向上的线条
canvasCtx.fillStyle = color1;
/* context.fillRect(x,y,width,height)
* x，y是坐标
* width，height线条的宽高
*/
canvasCtx.fillRect(oW / 2 + (i * 8), oH / 2, 2, -barHeight);
canvasCtx.fillRect(oW / 2 - (i * 8), oH / 2, 2, -barHeight);
// 绘制向下的线条
canvasCtx.fillStyle = color2;
canvasCtx.fillRect(oW / 2 + (i * 8), oH / 2, 2, barHeight);
canvasCtx.fillRect(oW / 2 - (i * 8), oH / 2, 2, barHeight);
}
};
draw();
})
}
})
}
</script>
</body>
</html>
总结
以上所述是小编给大家介绍的JS实现可视化音频效果的实例代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对网站的支持！
如果你觉得本文对你有帮助，欢迎转载，烦请注明出处，谢谢！
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