js可视化音频

html部分

js部分

  实例化新对象（path2为音频的路径），

initAu.audioInit();初始化音频

 initAu = au(path2);
 initAu.audioInit();

 

 可视化音频对象

/**
 * 创建可视化音频的函数
 * @param src  音频路径
 */
var au = function (src) {
    var au = new Object();
    au.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext;
    au.mp3 = src;
    au.audio = new Audio(src);
    au.ctx = new AudioContext();
    au.analyser = au.ctx.createAnalyser();
    au.audioSrc = au.ctx.createMediaElementSource(au.audio);
    au.audioSrc.connect(au.analyser);
    au.analyser.connect(au.ctx.destination);
    au.frequencyData = new Uint8Array(au.analyser.frequencyBinCount);
    au.canvas = document.getElementById('canvas');
    au.cwidth = au.canvas.width;
    au.cheight = au.canvas.height - 1;
    au.meterWidth = 5;
    au.gap = 2;
    au.speed=10;
    au.capHeight = 1;
    au.capStyle = '#fff';
    au.meterNum =  au.canvas.width/ (10 + 2);
    au.capYPositionArray = [];
    au.ctx = au.canvas.getContext('2d');
    au.gradient = au.ctx.createLinearGradient(0, 0, 0, 300);
    au.gradient.addColorStop(1, '#0f0');
    au.gradient.addColorStop(0.5, '#ff0');
    au.gradient.addColorStop(0, '#f00');
    au.time;
    au.randerFrame = function () {
        var array = new Uint8Array(au.analyser.frequencyBinCount);
        au.analyser.getByteFrequencyData(array);
        var step = Math.round(array.length / au.meterNum); //sample limited data from the total array
        au.ctx.clearRect(0, 0, au.cwidth, au.cheight);
        for (var i = 0; i < au.meterNum; i++) {
            var value = array[i * step];
            if (au.capYPositionArray.length < Math.round(au.meterNum)) {
                au.capYPositionArray.push(value);
            }
            au.ctx.fillStyle = au.capStyle;
            if (value < au.capYPositionArray[i]) {
                au.ctx.fillRect(i * 12, au.cheight-10 - (--au.capYPositionArray[i]), au.meterWidth, au.capHeight);
            }
            else {
                au.ctx.fillRect(i * 12, au.cheight - value, au.meterWidth, au.capHeight);
                au.capYPositionArray[i] = value;
            }
            au.ctx.fillStyle = au.gradient; //set the filllStyle to gradient for a better look
            au.ctx.fillRect(i * 12, au.cheight - value + au.capHeight, au.meterWidth, au.cheight+220); //the meter
        }

        //获取音频播放的进度
        var sumTime = parseInt(au.audio.duration);
        if(sumTime==NaN){
            au.randerFrame();
        }

        var currentTime = parseInt(au.audio.currentTime);
        var Percentage = (currentTime / sumTime) * 100;
        var width = 0.6 * Percentage + "vw";
        $(".music-range").val(Percentage);
        $("#bar_box").css({
            "width": width
        });
        var timeData = timeFormat(currentTime),timeData1=timeFormat(sumTime);
        middle_bot.timeData = timeData+" / "+timeData1;
        if(sumTime==currentTime){
            clearInterval(au.time);
            middle_bot.audioP=false;
            $("#playDiv").html(" ");
        }
        console.log("sumTime : "+sumTime+"  currentTime : "+au.audio.duration);
    };
    au.audioInit=function(){
        au.audio.addEventListener("canplay",function () {
            au.randerFrame();
        })
    };
    /**
     * 跳转播放
     */
    au.seek=function(val){
        var sumTime = parseInt(au.audio.duration);
        console.log("sumTime : "+sumTime);
        var currentTime = parseInt((val / 100) * sumTime);
        var width = 0.6 * val + "vw";
        $("#bar_box").css({
            "width": width
        });
        au.audio.currentTime=currentTime;
        var timeData = timeFormat(currentTime),timeData1=timeFormat(sumTime);
        middle_bot.timeData = timeData+" / "+timeData1;
    };
    /**
     * 播放开始
     */
    au.audioPlay = function () {
        console.log("播放");
        au.audio.play();
        au.time = setInterval(au.randerFrame, au.speed);
    };
    /**
     * 暂停播放
     */
    au.audioPause = function () {
        console.log("暂停");
        clearInterval(au.time);
        au.audio.pause();
    };
    /**
     * 重置
     */
    au.audioRest = function () {
        au.audio.remove();
    };

    au.audioChange=function (path) {
        au.audio.src=path;
    };
    return au;
};

第二种：简单的可视化处理

 var canvas = document.createElement("canvas");
    canvas.width = 100;
    canvas.height = 180;
    var ctx = canvas.getContext("2d");
    ctx.fillStyle = "red";
    ctx.strokeStyle = "blue";
    ctx.lineCap = "round";
    var auctx;

    window.onload = () => {
        document.body.appendChild(canvas);
        auctx = new(window.AudioContext || window.webkitAudioContext)();
        startAudio();
    }

    var buffer, src, analyser, buffLen;
    var barWidth, dataArray;

    function startAudio() {
        var url = "1.mp3";
        var request = new XMLHttpRequest();
        request.open('GET', url, true);
        request.responseType = 'arraybuffer';
        request.onload = function() {
            auctx.decodeAudioData(request.response, function(buffer) {
                buffer = buffer;
                src = auctx.createBufferSource();
                src.buffer = buffer;
                src.loop = false;
                src.connect(auctx.destination);
                src.start(0);
                analyser = auctx.createAnalyser();
                src.connect(analyser);
                analyser.connect(auctx.destination);
                analyser.fftSize = 256;
                buffLen = analyser.frequencyBinCount;
                dataArray = new Uint8Array(buffLen);
                barWidth = (500 - 2 * buffLen - 4) / buffLen * 2.5;
                ctx.lineWidth = barWidth;
                draw();
            });
        }
        request.send();
    }

    function draw() {
        ctx.fillRect(0, 0, 500, 180);
        analyser.getByteFrequencyData(dataArray);
        for (var i = 0; i < buffLen; i++) {
            ctx.beginPath();
            ctx.moveTo(4 + 2 * i * barWidth + barWidth / 2, 178 - barWidth / 2);
            ctx.lineTo(4 + 2 * i * barWidth + barWidth / 2, 178 - dataArray[i] * 0.65 - barWidth / 2);
            ctx.stroke();

        }
        requestAnimationFrame(draw);

    }