{"id":9505,"date":"2020-07-27T23:51:11","date_gmt":"2020-07-27T15:51:11","guid":{"rendered":"https:\/\/www.zhangxinxu.com\/wordpress\/?p=9505"},"modified":"2020-07-27T23:51:11","modified_gmt":"2020-07-27T15:51:11","slug":"js-audio-clip-copy-upload","status":"publish","type":"post","link":"https:\/\/www.zhangxinxu.com\/wordpress\/2020\/07\/js-audio-clip-copy-upload\/","title":{"rendered":"JS\u7eaf\u524d\u7aef\u5b9e\u73b0audio\u97f3\u9891\u526a\u88c1\u526a\u5207\u590d\u5236\u64ad\u653e\u4e0e\u4e0a\u4f20"},"content":{"rendered":"<p>by <a href=\"https:\/\/www.zhangxinxu.com\/\">zhangxinxu<\/a> from <a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/?p=9505\">https:\/\/www.zhangxinxu.com\/wordpress\/?p=9505<\/a><br \/>\n\u672c\u6587\u6b22\u8fce\u5206\u4eab\u4e0e\u805a\u5408\uff0c\u5168\u6587\u8f6c\u8f7d\u5c31\u4e0d\u5fc5\u4e86\uff0c\u5c0a\u91cd\u7248\u6743\uff0c\u5708\u5b50\u5c31\u8fd9\u4e48\u5927\uff0c\u82e5\u6025\u7528\u53ef\u4ee5\u8054\u7cfb\u6388\u6743\u3002<\/p>\n<p><script>window.wxShareImgUrl = 'https:\/\/www.zhangxinxu.com\/study\/image\/share\/20207-audio-clip.jpg';<\/script><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/image.zhangxinxu.com\/image\/blog\/202007\/audio-clip-cover.jpg\" width=\"480\" height=\"310\" alt=\"\u97f3\u9891\u5728\u7ebf\u526a\u8f91\u4e0e\u5904\u7406\" class=\"alignright clip thumb size-medium\" loading=\"lazy\" \/><\/p>\n<p>\u80cc\u666f\u662f\u8fd9\u6837\u7684\uff0c\u7528\u6237\u4e0a\u4f20\u97f3\u9891\u6587\u4ef6\uff0c\u53ef\u80fd\u53ea\u9700\u8981\u51e0\u5341\u79d2\u5c31\u591f\u4e86\uff0c\u4f46\u662f\u5e38\u89c4\u7684\u97f3\u4e50\u90fd\u89813~5\u5206\u949f\uff0c80%\u7684\u6d41\u91cf\u90fd\u662f\u4e0d\u9700\u8981\u7684\uff0c\u8981\u662f\u5c31\u8fd9\u4e48\u4f20\u4e0a\u53bb\uff0c\u5176\u5b9e\u662f\u6d41\u91cf\u7684\u6d6a\u8d39\uff0c\u5982\u679c\u53ef\u4ee5\u5728\u524d\u7aef\u5c31\u8fdb\u884c\u526a\u88c1\uff0c\u4e5f\u5c31\u662f\u53ea\u53d6\u524d\u9762\u4e00\u6bb5\u65f6\u95f4\u7684\u97f3\u9891\uff0c\u5c82\u4e0d\u662f\u53ef\u4ee5\u7ed9\u516c\u53f8\u7701\u5f88\u591a\u6d41\u91cf\u8d39\u7528\uff0c\u524d\u7aef\u7684\u4e1a\u52a1\u4ef7\u503c\u5c31\u4f53\u73b0\u4e86\u3002<\/p>\n<p>\u5173\u952e\u5982\u4f55\u5b9e\u73b0\u5462\uff1f<\/p>\n<p>\u4e0b\u9762\uff0c\u5c31\u4ee5\u201c\u622a\u53d6\u7528\u6237\u4e0a\u4f20\u97f3\u9891\u524d3\u79d2\u5185\u5bb9\u201d\u7684\u9700\u6c42\u793a\u610f\u4e0b\u5982\u4f55\u501f\u52a9Web Audio API\u5b9e\u73b0\u97f3\u9891\u7684\u90e8\u5206\u590d\u5236\u4e0e\u64ad\u653e\u529f\u80fd\u3002<\/p>\n<h3>\u4e00\u3001\u4e0d\u54d4\u54d4\uff0c\u76f4\u63a5\u6b63\u9898<\/h3>\n<p>\u5b9e\u73b0\u6b65\u9aa4\u5982\u4e0b\u3002<\/p>\n<h4>1. File\u5bf9\u8c61\u8f6cArrayBuffer<\/h4>\n<p>\u5728Web\u7f51\u9875\u4e2d\uff0c\u7528\u6237\u9009\u62e9\u7684\u6587\u4ef6\u662f\u4e2afile\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u8fd9\u4e2a\u6587\u4ef6\u5bf9\u8c61\u8f6c\u6362\u6210Blob\u3001ArrayBuffer\u6216\u8005Base64\u3002<\/p>\n<p>\u5728\u97f3\u9891\u5904\u7406\u8fd9\u91cc\uff0c\u90fd\u662f\u4f7f\u7528ArrayBuffer\u8fd9\u4e2a\u6570\u636e\u7c7b\u578b\u3002<\/p>\n<p>\u4ee3\u7801\u5982\u4e0b\u6240\u793a\uff0c\u5047\u8bbefile\u7c7b\u578b\u7684\u6587\u4ef6\u9009\u62e9\u6846\u7684id\u662f<code>'file'<\/code>\u3002<\/p>\n<pre>file.onchange = function (event) {\r\n    var file = event.target.files[0];\r\n    <span style=\"color:green;\">\/\/ \u5f00\u59cb\u8bc6\u522b<\/span>\r\n    var reader = new FileReader();\r\n    reader.onload = function (event) {\r\n        var arrBuffer = event.target.result;\r\n        <span style=\"color:green;\">\/\/ arrBuffer\u5c31\u662f\u5305\u542b\u97f3\u9891\u6570\u636e\u7684ArrayBuffer\u5bf9\u8c61<\/span>\r\n    });\r\n    reader.readAsArrayBuffer(file);\r\n};<\/pre>\n<p>\u4f7f\u7528\u7684\u662f<code>readAsArrayBuffer()<\/code>\u65b9\u6cd5\uff0c\u65e0\u8bba\u662fMP3\u683c\u5f0f\u3001OGG\u683c\u5f0f\u8fd8\u662fWAV\u683c\u5f0f\uff0c\u90fd\u53ef\u4ee5\u8f6c\u6362\u6210ArrayBuffer\u7c7b\u578b\u3002<\/p>\n<h4>2. ArrayBuffer\u8f6cAudioBuffer<\/h4>\n<p>\u8fd9\u91cc\u7684ArrayBuffer\u76f8\u5bf9\u4e8e\u628a\u97f3\u9891\u6587\u4ef6\u6570\u7ec4\u5316\u4e86\uff0c\u5927\u5bb6\u53ef\u4ee5\u7406\u89e3\u4e3a\u628a\u97f3\u9891\u6587\u4ef6\u5206\u89e3\u6210\u4e00\u6bb5\u4e00\u6bb5\u7684\uff0c\u585e\u8fdb\u4e86\u4e00\u4e2a\u4e00\u4e2a\u6709\u5730\u5740\u7684\u5c0f\u5c4b\u5b50\u91cc\uff0c\u5728\u8ba1\u7b97\u673a\u9886\u57df\u79f0\u4e3a\u201c\u7f13\u51b2\u533a\u201d\uff0c\u5c31\u662f\u5355\u8bcdBuffer\u7684\u610f\u601d\u3002<\/p>\n<p>\u6240\u8c13\u97f3\u9891\u7684\u526a\u88c1\uff0c\u5176\u5b9e\u5c31\u662f\u5e0c\u671b\u53ef\u4ee5\u590d\u5236\u97f3\u9891\u524d\u9762\u4e00\u6bb5\u65f6\u95f4\u7684\u5185\u5bb9\u3002<\/p>\n<p>\u4f46\u662f\u95ee\u9898\u6765\u4e86\uff0cArrayBuffer\u91cc\u9762\u7684\u6570\u636e\u5e76\u6ca1\u6709\u5206\u7c7b\uff0c\u7edf\u4e00\u5206\u89e3\u4e86\uff0c\u60f3\u8981\u51c6\u786e\u63d0\u53d6\u67d0\u4e00\u622a\u97f3\u9891\u6570\u636e\uff0c\u63d0\u53d6\u4e0d\u51fa\u6765\u3002<\/p>\n<p>\u6240\u4ee5\uff0c\u624d\u9700\u8981\u8f6c\u6362\u6210AudioBuffer\uff0c\u7eaf\u7cb9\u7684\u97f3\u9891\u6570\u636e\uff0c\u65b9\u4fbf\u63d0\u53d6\u3002<\/p>\n<p>AudioBuffer\u662f\u4e00\u4e2a\u4ec5\u4ec5\u5305\u542b\u97f3\u9891\u6570\u636e\u7684\u6570\u636e\u5bf9\u8c61\uff0c\u662fWeb Audio API\u4e2d\u7684\u4e00\u4e2a\u6982\u5ff5\u3002<\/p>\n<p>\u65e2\u7136\u8bf4\u5230\u4e86Web Audio API\uff0c\u90a3\u6211\u4eec\u5c31\u987a\u4fbf\u2026\u2026\u987a\u4fbf\u2026\u2026\uff0c\u60f3\u4e86\u60f3\uff0c\u8fd8\u662f\u4e0d\u5c55\u5f00\uff0c\u56e0\u4e3a\u592a\u5e9e\u6742\u4e86\uff0c\u8fd9Web Audio API\u81f3\u5c11\u6bd4<a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/2018\/03\/web-animations-api-dynamic-feature-animation\/\">Web Animation API<\/a>\u590d\u6742\u4e8610\u500d\uff0cAPI\u4e4b\u591a\uff0c\u4f53\u91cf\u4e4b\u5927\uff0c\u4e16\u95f4\u7f55\u89c1\uff0c\u60f3\u8981\u5b8c\u5168\u5403\u900f\u4e86\uff0c\u6ca1\u6709\u4e09\u5e74\u4e94\u8f7d\uff0c\u5543\u4e0d\u4e0b\u6765\u3002<\/p>\n<p>\u5982\u679c\u5927\u5bb6\u4e0d\u662f\u60f3\u8981\u7acb\u5fd7\u6210\u4e3a\u97f3\u89c6\u9891\u5904\u7406\u4e13\u5bb6\uff0c\u4ec5\u4ec5\u662f\u4e34\u65f6\u89e3\u51b3\u4e00\u70b9\u5c0f\u6bdb\u5c0f\u75c5\u7684\u95ee\u9898\uff0c\u5219\u4e0d\u5fc5\u6df1\u5165\uff0c\u5426\u5219\u8111\u5751\u75bc\uff0c\u4f7f\u7528MDN\u6587\u6863\u4e2d\u7684\u4e00\u4e9b\u6848\u4f8b\u4e1c\u62fc\u897f\u51d1\uff0c\u57fa\u672c\u7684\u6548\u679c\u4e5f\u80fd\u5f04\u51fa\u6765\u3002<\/p>\n<p>\u626f\u8fdc\u4e86\uff0c\u56de\u5230\u8fd9\u91cc\u3002<\/p>\n<p>AudioBuffer\u5927\u5bb6\u53ef\u4ee5\u7406\u89e3\u4e3a\u97f3\u4e50\u6570\u636e\uff0c\u90a3\u4e3a\u4ec0\u4e48\u53ebAudioBuffer\uff0c\u4e0d\u53ebAudioData\u5462\uff1f<\/p>\n<p>\u56e0\u4e3aBuffer\u662f\u4e2a\u4e13\u6709\u540d\u8bcd\uff0c\u76f4\u8bd1\u4e3a\u7f13\u51b2\u533a\uff0c\u5927\u5bb6\u53ef\u4ee5\u7406\u89e3\u4e3a\u9ad8\u901f\u516c\u8def\uff0cAudioBuffer\u5904\u7406\u6570\u636e\u66f4\u5feb\uff0c\u800c\u4e14\u8fd8\u6709\u5f88\u591a\u5ef6\u4f38\u7684API\uff0c\u5c31\u50cf\u662f\u9ad8\u901f\u516c\u8def\u4e0a\u7684\u670d\u52a1\u533a\uff0c\u6709\u5403\u6709\u559d\u8fd8\u6709\u52a0\u6cb9\u7684\u5730\u65b9\u3002<\/p>\n<p>AudioData\u4e00\u770b\u540d\u5b57\u5c31\u662f\u4e61\u4e0b\u571f\u9cd6\uff0c\u867d\u7136\u63a5\u5730\u6c14\uff0c\u4f46\u662f\uff0c\u5904\u7406\u597d\u51e0\u5146\u7684\u6570\u636e\u7684\u65f6\u5019\uff0c\u5c31\u6709\u4e9b\u5e26\u4e0d\u52a8\u4e86\uff0c\u5c31\u597d\u50cf\u9a91\u5c0f\u7535\u9a74\uff0c\u5728\u516c\u901f\u516c\u8def\u548c\u4e61\u9053\u53bf\u9053\u6ca1\u591a\u5927\u533a\u522b\uff0c\u4f46\u662f\u5982\u679c\u662f\u5f00\u8dd1\u8f66\uff0c\u5567\u5567\uff0c\u4e61\u4e0b\u8def\u5c31\u5e26\u4e0d\u52a8\u4e86\u3002<\/p>\n<p><strong>\u5982\u4f55\u624d\u80fd\u8f6c\u6362\u6210AudioBuffer\u5462\uff1f<\/strong><\/p>\n<p>\u4f7f\u7528AudioContext\u5bf9\u8c61\u7684<code>decodeAudioData()<\/code>\u65b9\u6cd5\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre>var audioCtx = new AudioContext();\r\n\r\naudioCtx.decodeAudioData(arrBuffer, function(audioBuffer) {\r\n    <span style=\"color:green;\">\/\/ audioBuffer\u5c31\u662fAudioBuffer<\/span>\r\n});<\/pre>\n<h4>3. \u590d\u5236AudioBuffer\u524d3\u79d2\u6570\u636e<\/h4>\n<p>AudioBuffer\u5bf9\u8c61\u662f\u4e00\u4e2a\u97f3\u9891\u4e13\u7528Buffer\u5bf9\u8c61\uff0c\u5305\u542b\u5f88\u591a\u97f3\u9891\u4fe1\u606f\uff0c\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u97f3\u9891\u65f6\u957f <code>duration<\/code><\/li>\n<li>\u58f0\u9053\u6570\u91cf <code>numberOfChannels<\/code><\/li>\n<li>\u91c7\u6837\u7387 <code>sampleRate<\/code><\/li>\n<\/ul>\n<p>\u7b49\u3002<\/p>\n<p>\u5305\u62ec\u4e00\u4e9b\u97f3\u9891\u58f0\u9053\u6570\u636e\u5904\u7406\u65b9\u6cd5\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li>\u83b7\u53d6\u901a\u9053\u6570\u636e <code>getChannelData()<\/code><\/li>\n<li>\u590d\u5236\u901a\u9053\u6570\u636e <code>copyFromChannel()<\/code><\/li>\n<li>\u5199\u5165\u901a\u9053\u6570\u636e <code>copyToChannel()<\/code><\/li>\n<\/ul>\n<p>\u6587\u6863\u89c1\u8fd9\u91cc\uff1a<a href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/AudioBuffer\" rel=\"noopener\" target=\"_blank\">https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/API\/AudioBuffer<\/a> <\/p>\n<p>\u6240\u4ee5\uff0c\u5b9e\u73b0\u7684\u539f\u7406\u5f88\u7b80\u5355\uff0c\u521b\u5efa\u4e00\u4e2a\u7a7a\u7684AudioBuffer\uff0c\u590d\u5236\u73b0\u6709\u7684\u901a\u9053\u6570\u636e\u524d3\u79d2\u7684\u6570\u636e\uff0c\u7136\u540e\u590d\u5236\u7684\u5185\u5bb9\u5199\u5165\u5230\u8fd9\u4e2a\u7a7a\u7684AudioBuffer\uff0c\u4e8e\u662f\u6211\u4eec\u5c31\u5f97\u5230\u4e86\u4e00\u4e2a\u526a\u88c1\u540e\u7684\u97f3\u9891Buffer\u6570\u636e\u4e86\u3002<\/p>\n<p>\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<pre><span style=\"color:green;\">\/\/ \u58f0\u9053\u6570\u91cf\u548c\u91c7\u6837\u7387<\/span>\r\nvar channels = audioBuffer.numberOfChannels;\r\nvar rate = audioBuffer.sampleRate;\r\n\r\n<span style=\"color:green;\">\/\/ \u622a\u53d6\u524d3\u79d2<\/span>\r\nvar startOffset = 0;\r\nvar endOffset = rate * 3;\r\n<span style=\"color:green;\">\/\/ 3\u79d2\u5bf9\u5e94\u7684\u5e27\u6570<\/span>\r\nvar frameCount = endOffset - startOffset;\r\n\r\n<span style=\"color:green;\">\/\/ \u521b\u5efa\u540c\u6837\u91c7\u7528\u7387\u3001\u540c\u6837\u58f0\u9053\u6570\u91cf\uff0c\u957f\u5ea6\u662f\u524d3\u79d2\u7684\u7a7a\u7684AudioBuffer<\/span>\r\nvar newAudioBuffer = new AudioContext().createBuffer(channels, endOffset - startOffset, rate);\r\n<span style=\"color:green;\">\/\/ \u521b\u5efa\u4e34\u65f6\u7684Array\u5b58\u653e\u590d\u5236\u7684buffer\u6570\u636e<\/span>\r\nvar anotherArray = new Float32Array(frameCount);\r\n<span style=\"color:green;\">\/\/ \u58f0\u9053\u7684\u6570\u636e\u7684\u590d\u5236\u548c\u5199\u5165<\/span>\r\nvar offset = 0;\r\nfor (var channel = 0; channel &lt; channels; channel++) {\r\n    audioBuffer.copyFromChannel(anotherArray, channel, startOffset);\r\n    newAudioBuffer.copyToChannel(anotherArray, channel, offset);\r\n}\r\n\r\n<span style=\"color:green;\">\/\/ newAudioBuffer\u5c31\u662f\u5168\u65b0\u7684\u590d\u5236\u76843\u79d2\u957f\u5ea6\u7684AudioBuffer\u5bf9\u8c61<\/span><\/pre>\n<p>\u4e0a\u9762JavaScript\u4ee3\u7801\u4e2d\u7684\u53d8\u91cf<code>newAudioBuffer<\/code>\u5c31\u662f\u5168\u65b0\u7684\u590d\u5236\u76843\u79d2\u957f\u5ea6\u7684AudioBuffer\u5bf9\u8c61\u3002<\/p>\n<h4>4. \u4f7f\u7528newAudioBuffer\u505a\u70b9\u4ec0\u4e48\uff1f<\/h4>\n<p>\u5176\u5b9e\u5e94\u8be5\u662f\u6709\u4e86AudioBuffer\u5bf9\u8c61\u540e\u6211\u4eec\u53ef\u4ee5\u505a\u70b9\u4ec0\u4e48\u3002<\/p>\n<p>\u80fd\u505a\u5f88\u591a\u4e8b\u60c5\u3002<\/p>\n<p><strong>1) \u5982\u679c\u5e0c\u671b\u76f4\u63a5\u64ad\u653e<\/strong><\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u628aAudioBuffer\u7684\u6570\u636e\u4f5c\u4e3a\u97f3\u9891\u6570\u636e\u8fdb\u884c\u64ad\u653e<\/p>\n<pre><span style=\"color:green;\">\/\/ \u521b\u5efaAudioBufferSourceNode\u5bf9\u8c61<\/span>\r\nvar source = audioCtx.createBufferSource();\r\n<span style=\"color:green;\">\/\/ \u8bbe\u7f6eAudioBufferSourceNode\u5bf9\u8c61\u7684buffer\u4e3a\u590d\u5236\u76843\u79d2AudioBuffer\u5bf9\u8c61<\/span>\r\nsource.buffer = newAudioBuffer;\r\n<span style=\"color:green;\">\/\/ \u8fd9\u4e00\u53e5\u662f\u5fc5\u987b\u7684\uff0c\u8868\u793a\u7ed3\u675f\uff0c\u6ca1\u6709\u8fd9\u4e00\u53e5\u6ca1\u6cd5\u64ad\u653e\uff0c\u6ca1\u6709\u58f0\u97f3\r\n\/\/ \u8fd9\u91cc\u76f4\u63a5\u7ed3\u675f\uff0c\u5b9e\u9645\u4e0a\u53ef\u4ee5\u5bf9\u7ed3\u675f\u505a\u4e00\u4e9b\u7279\u6548\u5904\u7406<\/span>\r\nsource.connect(audioCtx.destination);\r\n<span style=\"color:green;\">\/\/ \u8d44\u6e90\u5f00\u59cb\u64ad\u653e<\/span>\r\nsource.start();<\/pre>\n<p><strong>2) \u5982\u679c\u5e0c\u671b\u5728&lt;audio&gt;\u5143\u7d20\u4e2d\u64ad\u653e<\/strong><\/p>\n<p>\u8fd9\u4e2a\u8fd8\u633a\u9ebb\u70e6\u7684\u3002<\/p>\n<p>\u4ece<code>&lt;audio&gt;<\/code>\u7684src\u5c5e\u6027\u83b7\u53d6\u97f3\u9891\u8d44\u6e90\uff0c\u518d\u8fdb\u884c\u5904\u7406\u662f\u7b80\u5355\u7684\uff0c\u7f51\u4e0a\u7684\u6848\u4f8b\u4e5f\u5f88\u591a\u3002<\/p>\n<p>\u4f46\u662f\uff0c\u60f3\u8981\u5904\u7406\u540e\u7684AudioBuffer\u518d\u53d8\u6210src\u8ba9<code>&lt;audio&gt;<\/code>\u5143\u7d20\u64ad\u653e\uff0c\u563f\u563f\uff0c\u5c31\u6ca1\u90a3\u4e48\u5bb9\u6613\u4e86\u3002<\/p>\n<p>\u6211<span class=\"hidden\">\uff08\u5f20\u946b\u65ed\uff09<\/span>\u627e\u4e86\u4e00\u5708\uff0c\u6ca1\u6709\u770b\u5230Web Audio API\u4e2d\u6709\u4e13\u95e8\u7684\u201c\u9006\u8f6c\u5f55\u201d\u65b9\u6cd5\u3002<\/p>\n<p>\u552f\u4e00\u53ef\u884c\u7684\u8def\u6570\u5c31\u662f\u6839\u636eAudioBuffer\u6570\u636e\uff0c\u91cd\u65b0\u6784\u5efa\u539f\u59cb\u7684\u97f3\u9891\u6570\u636e\u3002\u7814\u7a76\u4e86\u4e00\u756a\uff0c\u8f6c\u6210WAV\u683c\u5f0f\u76f8\u5bf9\u5bb9\u6613\uff0c\u60f3\u8981\u8f6c\u6362\u6210MP3\u683c\u5f0f\u6bd4\u8f83\u9ebb\u70e6\uff0c\u8fd9\u91cc\u6709\u4e2a\u9879\u76ee\uff1a<a href=\"https:\/\/github.com\/higuma\/mp3-lame-encoder-js\" rel=\"noopener\" target=\"_blank\">https:\/\/github.com\/higuma\/mp3-lame-encoder-js<\/a> \u4e0d\u8fc7\u81ea\u5df1\u6ca1\u9a8c\u8bc1\u8fc7\uff0c\u4e0d\u8fc7\u770b\u4ee3\u7801\u91cf\uff0c\u8fd8\u633a\u60ca\u4eba\u7684\u3002<\/p>\n<p>\u56e0\u6b64\uff0c\u6211\u4eec\u7684\u76ee\u6807\u8fd8\u662f\u8f6c\u5230WAV\u97f3\u9891\u6587\u4ef6\u751f\u6210\u4e0a\u5427\uff0c\u4e0b\u9762\u8fd9\u6bb5\u65b9\u6cd5\u662f\u4ece\u7f51\u4e0a\u627e\u7684AudioBuffer\u8f6cWAV\u6587\u4ef6\u7684\u65b9\u6cd5\uff0c\u4ee5Blob\u6570\u636e\u683c\u5f0f\u8fd4\u56de\u3002<\/p>\n<pre>\/\/ Convert AudioBuffer to a Blob using WAVE representation\r\nfunction bufferToWave(abuffer, len) {\r\n    var numOfChan = abuffer.numberOfChannels,\r\n    length = len * numOfChan * 2 + 44,\r\n    buffer = new ArrayBuffer(length),\r\n    view = new DataView(buffer),\r\n    channels = [], i, sample,\r\n    offset = 0,\r\n    pos = 0;\r\n\r\n    \/\/ write WAVE header\r\n    \/\/ \"RIFF\"\r\n    setUint32(0x46464952);\r\n    \/\/ file length - 8                      \r\n    setUint32(length - 8);\r\n    \/\/ \"WAVE\"                     \r\n    setUint32(0x45564157);\r\n    \/\/ \"fmt \" chunk\r\n    setUint32(0x20746d66);  \r\n    \/\/ length = 16                       \r\n    setUint32(16);  \r\n    \/\/ PCM (uncompressed)                               \r\n    setUint16(1); \r\n    setUint16(numOfChan);\r\n    setUint32(abuffer.sampleRate);\r\n    \/\/ avg. bytes\/sec\r\n    setUint32(abuffer.sampleRate * 2 * numOfChan);\r\n    \/\/ block-align\r\n    setUint16(numOfChan * 2);\r\n    \/\/ 16-bit (hardcoded in this demo)\r\n    setUint16(16);                           \r\n    \/\/ \"data\" - chunk\r\n    setUint32(0x61746164); \r\n    \/\/ chunk length                   \r\n    setUint32(length - pos - 4);                   \r\n\r\n    \/\/ write interleaved data\r\n    for(i = 0; i < abuffer.numberOfChannels; i++)\r\n        channels.push(abuffer.getChannelData(i));\r\n\r\n    while(pos < length) {\r\n         \/\/ interleave channels\r\n        for(i = 0; i < numOfChan; i++) {\r\n            \/\/ clamp\r\n            sample = Math.max(-1, Math.min(1, channels[i][offset])); \r\n            \/\/ scale to 16-bit signed int\r\n            sample = (0.5 + sample < 0 ? sample * 32768 : sample * 32767)|0; \r\n            \/\/ write 16-bit sample\r\n            view.setInt16(pos, sample, true);          \r\n            pos += 2;\r\n        }\r\n        \/\/ next source sample\r\n        offset++                                     \r\n    }\r\n\r\n    \/\/ create Blob\r\n    return new Blob([buffer], {type: \"audio\/wav\"});\r\n\r\n    function setUint16(data) {\r\n        view.setUint16(pos, data, true);\r\n        pos += 2;\r\n    }\r\n\r\n    function setUint32(data) {\r\n        view.setUint32(pos, data, true);\r\n        pos += 4;\r\n    }\r\n}<\/pre>\n<p>WAV\u683c\u5f0f\u7684\u517c\u5bb9\u6027\u8fd8\u662f\u5f886\u7684\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/image.zhangxinxu.com\/image\/blog\/202007\/2020-07-27_175434.png\" width=\"635\" height=\"350\" alt=\"wav\u517c\u5bb9\u6027\" class=\"alignnone size-medium\" \/><\/p>\n<p>\u51e1\u4e8b\u652f\u6301Web Audio API\u7684\u6d4f\u89c8\u5668\u90fd\u652f\u6301WAV\u683c\u5f0f\uff0c\u6240\u4ee5\uff0c\u6280\u672f\u4e0a\u5b8c\u5168\u53ef\u884c\u3002<\/p>\n<p>\u4e0b\u9762\u8fd9\u6bb5JS\u53ef\u4ee5\u5f97\u5230\u526a\u88c1\u540e\u7684WAV\u97f3\u9891\u7684Blob\u6570\u636e\u683c\u5f0f\uff1a<\/p>\n<pre>var blob = bufferToWave(newAudioBuffer, frameCount);<\/pre>\n<p>\u6709\u4e86Blob\u6570\u636e\uff0c\u63a5\u4e0b\u6765\u4e8b\u60c5\u5c31\u7b80\u5355\u4e86\u3002<\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u628aBlob\u6570\u636e\u8f6c\u6362\u6210URL\uff0c\u53ef\u4ee5\u4f7f\u7528<code>URL.createObjectURL()<\/code>\u751f\u6210\u4e00\u4e2aBlob\u94fe\u63a5\u3002<\/p>\n<p>\u5047\u8bbe\u9875\u9762\u4e0a\u6709\u5982\u4e0bHTML\u4ee3\u7801\uff1a<\/p>\n<pre>&lt;audio id=\"audio\" controls=\"\"&gt;&lt;\/audio&gt;<\/pre>\n<p>\u5219\u5982\u4e0b\u8bbe\u7f6e\uff0c\u5c31\u53ef\u4ee5\u70b9\u51fb\u4e0a\u9762\u7684<code>&lt;audio&gt;<\/code>\u5143\u7d20\u8fdb\u884c\u64ad\u653e\u4e86\u3002<\/p>\n<pre>audio.src = URL.createObjectURL(blob);<\/pre>\n<p>\u5982\u679c\u8981\u8f6c\u6362\u6210Base64\u5730\u5740\uff0c\u53ef\u4ee5\u8fd9\u4e48\u5904\u7406\uff1a<\/p>\n<pre>var reader2 = new FileReader();\r\nreader2.onload = function(event){\r\n    audio.src = event.target.result;\r\n};\r\nreader2.readAsDataURL(blob);<\/pre>\n<p><strong>3\uff09 \u5982\u679c\u5e0c\u671b\u4e0a\u4f20\u526a\u88c1\u7684\u97f3\u9891<\/strong><\/p>\n<p>\u6709\u4e86Blob\u6570\u636e\uff0c\u4e0a\u4f20\u8fd8\u4e0d\u662f\u6d12\u6d12\u6c34\u7684\u4e8b\u60c5\u3002<\/p>\n<p>\u53ef\u4ee5\u4f7f\u7528FormData\u8fdb\u884c\u4f20\u8f93\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre>var formData = new FormData();\r\nformData.append('audio', blob);\r\n<span style=\"color:green;\">\/\/ \u8bf7\u6c42\u8d70\u8d77<\/span>\r\nvar xhr = new XMLHttpRequest();\r\nxhr.open('POST', this.cgiGetImg, true);\r\n<span style=\"color:green;\">\/\/ \u8bf7\u6c42\u6210\u529f<\/span>\r\nxhr.onload = function () {\r\n};\r\n<span style=\"color:green;\">\/\/ \u53d1\u9001\u6570\u636e<\/span>\r\nxhr.send(formData);<\/pre>\n<p>\u6709demo\u53ef\u4ee5\u8fdb\u884c\u6548\u679c\u4f53\u9a8c\u7684\uff0c\u60a8\u53ef\u4ee5\u72e0\u72e0\u5730\u70b9\u51fb\u8fd9\u91cc\uff1a<a href=\"https:\/\/www.zhangxinxu.com\/study\/202007\/upload-audio-clip-play-demo.php\" rel=\"noopener\" target=\"_blank\">\u7528\u6237\u4e0a\u4f20\u7684MP3\u97f3\u9891\u526a\u88c1\u5e76\u64ad\u653edemo<\/a><\/p>\n<p>\u4f7f\u7528\u622a\u56fe\u793a\u610f\u5982\u4e0b\uff1a<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/image.zhangxinxu.com\/image\/blog\/202007\/2020-07-27_232335.png\" width=\"479\" height=\"225\" alt=\"\u58f0\u97f3\u68c0\u6d4b\u4e0e\u64ad\u653e\u793a\u610f\" class=\"alignnone size-medium\" \/><\/p>\n<h3>\u4e8c\u3001\u4e0d\u54d4\u54d4\uff0c\u76f4\u63a5\u7ed3\u8bed<\/h3>\n<p>\u672c\u6587\u5185\u5bb9\u5728\u5708\u5b50\u91cc\u7b97\u662f\u7a00\u7f3a\u7684\uff0c\u6587\u7ae0\u8d28\u91cf\u8fd8\u662f\u4e0d\u9519\u7684\u3002<\/p>\n<p>\u53ef\u60dc\uff0c\u4e0d\u592a\u5bb9\u6613\u88ab\u7528\u6237\u53d1\u73b0\u3002<\/p>\n<p>\u5373\u4f7f\u6709\u5206\u4eab\uff0c\u4e5f\u90fd\u662f\u77ed\u65f6\u95f4\u7684\u3002<\/p>\n<p>\u81ea\u5df1\u4e5f\u6ca1\u90a3\u4e48\u591a\u7cbe\u529b\u53bb\u793e\u4ea4\u5e73\u53f0\u6253\u7406\u3002<\/p>\n<p>\u6709\u4e9b\u53ef\u60dc\u3002<\/p>\n<p>\u53ef\u4ee5\u627e\u4e2a\u4eba\u517c\u804c\u6253\u7406\u81ea\u5df1\u7684\u8d26\u53f7\uff0c\u505a\u4e0b\u7c7b\u4f3c\u8fd0\u8425\u7684\u4e8b\u60c5\u5462\uff1f<img loading=\"lazy\" decoding=\"async\" src=\"\/\/image.zhangxinxu.com\/image\/emtion\/emoji\/1f914.svg\" width=\"20\" height=\"20\" align=\"absmiddle\"><\/p>\n<p>\u603b\u4e4b\uff0c\u611f\u8c22\u9605\u8bfb\uff0c\u5982\u679c\u672c\u6587\u5185\u5bb9\u6b63\u597d\u53ef\u4ee5\u89e3\u51b3\u4f60\u7684\u9700\u6c42\uff0c\u8bb0\u5f97\u5728\u5fc3\u91cc\u9762\u70b9\u4e2a\u8d5e\uff01<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/\/image.zhangxinxu.com\/image\/emtion\/emoji\/1f618.svg\" width=\"20\" height=\"20\" align=\"absmiddle\"><\/p>\n<p>\u672c\u6587\u4e3a\u539f\u521b\u6587\u7ae0\uff0c\u6b22\u8fce\u5206\u4eab\uff0c\u52ff\u5168\u6587\u8f6c\u8f7d\uff0c\u5982\u679c\u5b9e\u5728\u559c\u6b22\uff0c\u53ef\u6536\u85cf\uff0c\u6c38\u4e0d\u8fc7\u671f\uff0c\u4e14\u4f1a\u53ca\u65f6\u66f4\u65b0\u77e5\u8bc6\u70b9\u53ca\u4fee\u6b63\u9519\u8bef\uff0c\u9605\u8bfb\u4f53\u9a8c\u4e5f\u66f4\u597d\u3002<br \/>\n\u672c\u6587\u5730\u5740\uff1a<a href=\"https:\/\/www.zhangxinxu.com\/wordpress\/?p=9505\">https:\/\/www.zhangxinxu.com\/wordpress\/?p=9505<\/a><\/p>\n<p>\uff08\u672c\u7bc7\u5b8c\uff09<\/p>\n","protected":false},"excerpt":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/image.zhangxinxu.com\/image\/blog\/202007\/audio-clip-cover.jpg\" width=\"160\" height=\"103\" alt=\"\u97f3\u9891\u5728\u7ebf\u526a\u8f91\u4e0e\u5904\u7406\" class=\"alignright size-medium\" loading=\"lazy\" \/><\/p>\n<p>\u672c\u6587\u6f14\u793a\u4e86\u5982\u4f55\u7eaf\u524d\u7aef\u5bf9MP3\u3001WAV\u3001OGG\u7b49\u683c\u5f0f\u97f3\u9891\u8fdb\u884c\u526a\u8f91\u3001\u526a\u88c1\u3001\u526a\u5207\u3001\u590d\u5236\u3001\u64ad\u653e\u4ee5\u53ca\u4e0a\u4f20\u7b49\u5904\u7406\uff0c\u4f7f\u7528Web Audio API\uff0c\u6709\u5b8c\u6574\u7684\u4ee3\u7801\uff0c\u8fd8\u6709\u5728\u7ebfdemo\u6f14\u793a\u9875\u9762\uff0c\u5373\u63d2\u5373\u7528\uff0c\u5e0c\u671b\u672c\u6587\u5185\u5bb9\u53ef\u4ee5\u5bf9\u4f60\u7684\u5de5\u4f5c\u6709\u6240\u5e2e\u52a9\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[180],"tags":[215,874,489,1638,1644,1137,1642,1641,1640,638,1643,1233],"_links":{"self":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/9505"}],"collection":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=9505"}],"version-history":[{"count":0,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/posts\/9505\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=9505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=9505"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhangxinxu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=9505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}