Question

我有以下html页面，我正在尝试展示一个用于演示本地存储的mp3的音频可视化工具的课程：

<!doctype html>
<html>
<head>
    <header name = "Access-Control-Allow-Origin" value = "*" /> 
    <style type = "text/css">
            div#mp3_player{ width: 500px; height: 60px; background: #000; padding: 5px; margin: 50px auto;}
        div#mp3_player > div > audio{ width: 500px; background: #000; float: left; }
        div#mp3_player > canvas { width: 500px; height: 30px; background: #002D3C; float: left;}
    </style>
    <script>
    //create new instance of audio 
    var audio = new Audio();
    audio.src = 'C:/Users/Adam/Desktop/1901.m4a';
    audio.controls = true;
    audio.loop = true;
    audio.autoplay = true;

    var canvas, ctx, source, context, analyser, fbc_array, bars, bar_x, bar_width, bar_height;

    window.addEventListener("load", initMp3Player, false);


    function frameLooper(){
        window.webkitRequestAnimationFrame(frameLooper);
        fbc_array = new Uint8Array(analyser.frequencyBinCount);
        analyser.getByteFrequencyData(fbc_array);
        ctx.clearRect(0, 0, canvas.width, canvas.height);
        ctx.fillStyle = "#00CCFF";
        bars = 100;
        for (var i = 0; i < bars; i++){
            bar_x = i * 3;
            bar_width = 2;
            bar_height = -(fbc_array[i]/2);
            ctx.fillRect(bar_x, canvas.height, bar_width, bar_height);
        }
    }

    function initMp3Player(){
        document.getElementById('audio_box').appendChild(audio);
        context = new AudioContext();
        analyser = context.createAnalyser();
        canvas = document.getElementById('analyser_render');
        ctx = canvas.getContext('2d');
        source = context.createMediaElementSource(audio);
        source.connect(analyser);
        analyser.connect(context.destination);
        frameLooper();
    }

    </script>

</head>

<body>
    <div id = "mp3_player">
        <div id = "audio_box"></div>
        <canvas id = "analyser_render"></canvas>
    </div>

</body>

在使用脚本标记中的所有代码（不包括行下方的代码）之前，我已经自动播放了mp3文件

audio.autoplay = true;

但是当我包含frameLooper函数时，我得到消息“MediaElementAudioSource由于CORS访问限制而输出零”。无论如何都要绕过这个，因为它是一个本地文件？

Answer 1

在初始化Audio对象后，添加以下内容：

audio.crossOrigin = "anonymous";

这应该可以防止CORS访问限制。

由于CORS访问限制本地mp3文件，MediaElementAudioSource输出零

1 个答案: