{"id":235233,"date":"2024-05-12T10:16:28","date_gmt":"2024-05-12T02:16:28","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/235233.html"},"modified":"2024-05-12T10:16:36","modified_gmt":"2024-05-12T02:16:36","slug":"javascript%e5%a6%82%e4%bd%95%e8%8e%b7%e5%8f%96%e6%b5%8f%e8%a7%88%e5%99%a8%e4%b8%ad%e8%a7%86%e9%a2%91%e7%9a%84%e7%a0%81%e7%8e%87%e4%bf%a1%e6%81%af","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/235233.html","title":{"rendered":"JavaScript\u5982\u4f55\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f"},"content":{"rendered":"

\"JavaScript\u5982\u4f55\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\"<\/p>\n

\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\u5bf9\u4e8e\u5f00\u53d1\u8005\u800c\u8a00\u662f\u4e00\u9879\u91cd\u8981\u4e14\u6709\u7528\u7684\u529f\u80fd\u3002\u5b83\u4e3b\u8981\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528HTML5\u7684<video><\/code>\u6807\u7b7e\u3001JavaScript\u7684MediaSource Extensions<\/code>\uff08MSE\uff09\u3001video<\/code>\u5143\u7d20\u7684\u5c5e\u6027\u4ee5\u53ca\u5229\u7528\u7b2c\u4e09\u65b9\u5e93<\/strong> \u5b9e\u73b0\u3002\u8fd9\u4e9b\u65b9\u6cd5\u80fd\u5e2e\u52a9\u5f00\u53d1\u8005\u76d1\u63a7\u548c\u8c03\u6574\u89c6\u9891\u64ad\u653e\u8d28\u91cf\u3001\u4f18\u5316\u7528\u6237\u4f53\u9a8c\u3001\u4ee5\u53ca\u9488\u5bf9\u4e0d\u540c\u7f51\u7edc\u6761\u4ef6\u505a\u51fa\u9002\u5f53\u8c03\u6574\u3002\u5c24\u5176\u662f\u5229\u7528MediaSource Extensions<\/code>\uff08MSE\uff09<\/strong>\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u66f4\u8be6\u7ec6\u5730\u63a7\u5236\u89c6\u9891\u5185\u5bb9\u7684\u7f13\u51b2\u548c\u7801\u7387\u9002\u914d\uff0c\u6709\u6548\u63d0\u9ad8\u89c6\u9891\u7684\u64ad\u653e\u6027\u80fd\u4e0e\u89c2\u770b\u4f53\u9a8c\u3002<\/p>\n<\/p>\n

\u4e0b\u9762\uff0c\u6211\u4eec\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u8fd9\u4e9b\u65b9\u6cd5\uff1a<\/p>\n<\/p>\n

\u4e00\u3001HTML5 VIDEO\u6807\u7b7e<\/h3>\n<\/p>\n

HTML5\u5f15\u5165\u7684<video><\/code>\u6807\u7b7e\u4e3a\u5d4c\u5165\u89c6\u9891\u5230\u7f51\u9875\u63d0\u4f9b\u4e86\u7b80\u5355\u76f4\u63a5\u7684\u65b9\u6cd5\u3002\u7136\u800c\uff0c\u8981\u76f4\u63a5\u83b7\u53d6\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\u5c31\u9700\u8981\u4f9d\u8d56\u89c6\u9891\u5143\u6570\u636e\u3002<\/p>\n<\/p>\n

    \n
  1. \n

    \u5728\u7f51\u9875\u4e2d\u5d4c\u5165\u89c6\u9891<\/strong>\uff1a\u901a\u8fc7\u5d4c\u5165<video><\/code>\u6807\u7b7e\uff0c\u5728\u5176src<\/code>\u5c5e\u6027\u4e2d\u6307\u5b9a\u89c6\u9891\u6e90\uff0c\u5373\u53ef\u5728\u9875\u9762\u4e2d\u663e\u793a\u89c6\u9891\u3002\u7136\u800c\uff0c<video><\/code>\u6807\u7b7e\u672c\u8eab\u5e76\u4e0d\u63d0\u4f9b\u76f4\u63a5\u7684API\u6765\u8bfb\u53d6\u7801\u7387\u4fe1\u606f\u3002<\/p>\n<\/p>\n<\/li>\n

  2. \n

    \u4f7f\u7528\u5c5e\u6027\u548c\u4e8b\u4ef6\u76d1\u542c<\/strong>\uff1a\u901a\u8fc7\u76d1\u542c<video><\/code>\u6807\u7b7e\u7684loadedmetadata<\/code>\u4e8b\u4ef6\uff0c\u53ef\u4ee5\u5728\u89c6\u9891\u7684\u5143\u6570\u636e\u52a0\u8f7d\u5b8c\u6210\u540e\u83b7\u53d6\u89c6\u9891\u7684\u5bbd\u9ad8\u3001\u65f6\u957f\u7b49\u4fe1\u606f\uff0c\u4f46\u83b7\u53d6\u4e0d\u5230\u7801\u7387\u4fe1\u606f\u3002\u56e0\u6b64\uff0c\u76f4\u63a5\u901a\u8fc7<video><\/code>\u6807\u7b7e\u83b7\u53d6\u89c6\u9891\u7801\u7387\u4fe1\u606f\u6709\u4e00\u5b9a\u5c40\u9650\u6027\u3002<\/p>\n<\/p>\n<\/li>\n<\/ol>\n

    \u4e8c\u3001MEDIASOURCE EXTENSIONS (MSE)<\/h3>\n<\/p>\n

    MediaSource Extensions<\/code>\uff08MSE\uff09\u4e3a\u89c6\u9891\u63d0\u4f9b\u4e86\u66f4\u4e30\u5bcc\u7684\u6d4f\u89c8\u5668\u7aef\u63a7\u5236\u529f\u80fd\uff0c\u5305\u62ec\u8c03\u6574\u7801\u7387\u3002<\/p>\n<\/p>\n

      \n
    1. \n

      \u521b\u5efaMediaSource\u5bf9\u8c61<\/strong>\uff1a\u9996\u5148\uff0c\u521b\u5efa\u4e00\u4e2aMediaSource<\/code>\u5bf9\u8c61\uff0c\u5e76\u5c06\u5176\u4e0e<video><\/code>\u6807\u7b7e\u5173\u8054\u3002\u8fd9\u5141\u8bb8\u76f4\u63a5\u64cd\u4f5c\u89c6\u9891\u6d41\u7684\u7f13\u51b2\u533a\u3002<\/p>\n<\/p>\n<\/li>\n

    2. \n

      \u5206\u6bb5\u8bf7\u6c42\u89c6\u9891\u5185\u5bb9<\/strong>\uff1a\u901a\u8fc7MSE\u53ef\u4ee5\u5b9e\u73b0\u5bf9\u89c6\u9891\u6d41\u7684\u7ec6\u7c92\u5ea6\u63a7\u5236\uff0c\u5305\u62ec\u6839\u636e\u7f51\u7edc\u60c5\u51b5\u52a8\u6001\u8c03\u6574\u89c6\u9891\u8d28\u91cf\u548c\u7801\u7387\u3002\u5f00\u53d1\u8005\u53ef\u4ee5\u76d1\u542c\u7f51\u7edc\u72b6\u51b5\uff0c\u52a8\u6001\u9009\u62e9\u4e0d\u540c\u7801\u7387\u7684\u89c6\u9891\u5206\u6bb5\u8fdb\u884c\u52a0\u8f7d\u548c\u64ad\u653e\uff0c\u4f46\u9700\u8981\u624b\u52a8\u5206\u6790\u89c6\u9891\u7247\u6bb5\u7684\u7801\u7387\u4fe1\u606f\uff0c\u5e76\u81ea\u884c\u5b9e\u73b0\u7801\u7387\u7684\u9009\u62e9\u903b\u8f91\u3002<\/p>\n<\/p>\n<\/li>\n<\/ol>\n

      \u4e09\u3001VIDEO\u5143\u7d20\u7684\u5c5e\u6027<\/h3>\n<\/p>\n

      \u867d\u7136<video><\/code>\u5143\u7d20\u672c\u8eab\u4e0d\u63d0\u4f9b\u76f4\u63a5\u83b7\u53d6\u7801\u7387\u7684API\uff0c\u4f46\u7ed3\u5408\u5176\u5b83\u6280\u672f\uff0c\u5982MSE\uff0c\u5f00\u53d1\u8005\u8fd8\u662f\u53ef\u4ee5\u95f4\u63a5\u83b7\u5f97\u76f8\u5173\u4fe1\u606f\u3002<\/p>\n<\/p>\n

        \n
      1. \n

        \u5229\u7528getVideoPlaybackQuality<\/code>\u65b9\u6cd5<\/strong>\uff1a\u67d0\u4e9b\u6d4f\u89c8\u5668\u63d0\u4f9b\u4e86getVideoPlaybackQuality<\/code>\u65b9\u6cd5\uff0c\u901a\u8fc7\u8be5\u65b9\u6cd5\u53ef\u4ee5\u83b7\u53d6\u5305\u62ec\u4e22\u5e27\u6570\u7b49\u5728\u5185\u7684\u89c6\u9891\u64ad\u653e\u8d28\u91cf\u4fe1\u606f\uff0c\u95f4\u63a5\u53cd\u6620\u89c6\u9891\u7684\u7801\u7387\u60c5\u51b5\u3002<\/p>\n<\/p>\n<\/li>\n

      2. \n

        \u64ad\u653e\u4e8b\u4ef6\u76d1\u542c<\/strong>\uff1a\u901a\u8fc7\u76d1\u542c\u89c6\u9891\u64ad\u653e\u7684\u5404\u7c7b\u4e8b\u4ef6\uff0c\u7ed3\u5408\u6d4f\u89c8\u5668\u7684\u7f51\u7edcAPI\uff0c\u5982Navigation Timing API<\/code>\uff0c\u53ef\u4ee5\u5927\u81f4\u63a8\u65ad\u51fa\u89c6\u9891\u6d41\u7684\u7801\u7387\u60c5\u51b5\u3002<\/p>\n<\/p>\n<\/li>\n<\/ol>\n

        \u56db\u3001\u5229\u7528\u7b2c\u4e09\u65b9\u5e93<\/h3>\n<\/p>\n
          \n
        1. \n

          Video.js<\/strong>\uff1aVideo.js\u662f\u4e00\u4e2a\u6d41\u884c\u7684\u5f00\u6e90\u89c6\u9891\u64ad\u653e\u5668\u6846\u67b6\uff0c\u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684API \uff0c\u5305\u62ec\u5bf9<video><\/code>\u6807\u7b7e\u7684\u5c01\u88c5\uff0c\u4ee5\u53ca\u7528\u4e8e\u5904\u7406\u89c6\u9891\u64ad\u653e\u3001\u63a7\u5236\u64ad\u653e\u8d28\u91cf\u548c\u7801\u7387\u7684\u63d2\u4ef6\u3002<\/p>\n<\/p>\n<\/li>\n

        2. \n

          hls.js<\/strong>\uff1a\u5bf9\u4e8e\u4f7f\u7528HLS\uff08HTTP Live Streaming\uff09\u534f\u8bae\u7684\u89c6\u9891\uff0chls.js\u662f\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u5e93\u3002\u5b83\u5141\u8bb8\u5bf9HLS\u89c6\u9891\u8fdb\u884c\u66f4\u7ec6\u7c92\u5ea6\u7684\u63a7\u5236\uff0c\u5305\u62ec\u7801\u7387\u7684\u624b\u52a8\u6216\u81ea\u52a8\u9009\u62e9\u3002<\/p>\n<\/p>\n<\/li>\n<\/ol>\n

          \u901a\u8fc7\u4e0a\u8ff0\u65b9\u6cd5\uff0c\u5f00\u53d1\u8005\u53ef\u4ee5\u5728\u5404\u79cd\u573a\u666f\u4e0b\u83b7\u53d6\u548c\u63a7\u5236\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\u3002\u5c24\u5176\u662f\u5229\u7528MediaSource Extensions<\/code>\uff08MSE\uff09\u548c\u7b2c\u4e09\u65b9\u5e93<\/strong>\uff0c\u53ef\u4ee5\u5b9e\u73b0\u5bf9\u89c6\u9891\u64ad\u653e\u548c\u8d28\u91cf\u63a7\u5236\u7684\u7cbe\u7ec6\u7ba1\u7406\uff0c\u8fdb\u800c\u4f18\u5316\u7528\u6237\u4f53\u9a8c\u3002\u7136\u800c\uff0c\u6d89\u53ca\u89c6\u9891\u7801\u7387\u7684\u64cd\u4f5c\u5f80\u5f80\u9700\u8981\u8f83\u4e3a\u590d\u6742\u7684\u903b\u8f91\u548c\u5bf9\u5a92\u4f53\u6280\u672f\u7684\u6df1\u5165\u7406\u89e3\uff0c\u56e0\u6b64\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\u5e94\u5145\u5206\u6d4b\u8bd5\u4ee5\u786e\u4fdd\u6700\u4f73\u6548\u679c\u3002<\/p>\n<\/p>\n

          \u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n

          \u95ee\u98981\uff1a<\/strong> \u5982\u4f55\u4f7f\u7528JavaScript\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\uff1f<\/p>\n

          \u56de\u7b54\uff1a<\/strong> \u82e5\u8981\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528HTMLMediaElement<\/code>\u63a5\u53e3\u63d0\u4f9b\u7684videoTracks<\/code>\u5c5e\u6027\u6765\u8bbf\u95ee\u89c6\u9891\u8f68\u9053\uff0c\u5e76\u901a\u8fc7\u8f68\u9053\u4e0a\u7684bitRate<\/code>\u5c5e\u6027\u83b7\u53d6\u5f53\u524d\u64ad\u653e\u7684\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\u3002<\/p>\n

          \u4f8b\u5982\uff1a<\/p>\n

          const videoElement = document.getElementById('video'); \/\/ \u83b7\u53d6\u89c6\u9891\u5143\u7d20\nconst videoTrack = videoElement.videoTracks[0]; \/\/ \u83b7\u53d6\u89c6\u9891\u8f68\u9053\nconst bitRate = videoTrack.bitRate; \/\/ \u83b7\u53d6\u7801\u7387\u4fe1\u606f\nconsole.log('\u89c6\u9891\u7801\u7387\uff1a', bitRate);\n<\/code><\/pre>\n
          \u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u4f7f\u7528\u8be5\u65b9\u6cd5\u83b7\u53d6\u7684\u7801\u7387\u4fe1\u606f\u53ef\u80fd\u5e76\u4e0d\u662f\u5b9e\u65f6\u7684\uff0c\u5177\u4f53\u53d6\u51b3\u4e8e\u6d4f\u89c8\u5668\u7684\u5b9e\u73b0\u3002\u53e6\u5916\uff0c\u67d0\u4e9b\u6d4f\u89c8\u5668\u53ef\u80fd\u4e0d\u652f\u6301\u76f4\u63a5\u8bbf\u95ee\u7801\u7387\u4fe1\u606f\uff0c\u56e0\u6b64\u9700\u8981\u8fdb\u884c\u517c\u5bb9\u6027\u68c0\u6d4b\u3002<\/p>\n
          \u95ee\u98982\uff1a<\/strong> \u5982\u4f55\u901a\u8fc7JavaScript\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u6b63\u5728\u64ad\u653e\u89c6\u9891\u7684\u7801\u7387\uff1f<\/p>\n
          \u56de\u7b54\uff1a<\/strong> \u8981\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u5f53\u524d\u64ad\u653e\u89c6\u9891\u7684\u7801\u7387\uff0c\u53ef\u4ee5\u4f7f\u7528HTMLMediaElement<\/code>\u63a5\u53e3\u63d0\u4f9b\u7684videoTracks<\/code>\u5c5e\u6027\u6765\u8bbf\u95ee\u89c6\u9891\u8f68\u9053\uff0c\u5e76\u901a\u8fc7\u8f68\u9053\u4e0a\u7684bitRate<\/code>\u5c5e\u6027\u83b7\u53d6\u6b63\u5728\u64ad\u653e\u7684\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\u3002<\/p>\n
          const videoElement = document.getElementById('video'); \/\/ \u83b7\u53d6\u89c6\u9891\u5143\u7d20\nconst videoTrack = videoElement.videoTracks.find(track => track.selected); \/\/ \u83b7\u53d6\u5f53\u524d\u64ad\u653e\u7684\u89c6\u9891\u8f68\u9053\nconst bitRate = videoTrack.bitRate; \/\/ \u83b7\u53d6\u7801\u7387\u4fe1\u606f\nconsole.log('\u5f53\u524d\u64ad\u653e\u89c6\u9891\u7684\u7801\u7387\uff1a', bitRate);\n<\/code><\/pre>\n
          \u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u4f7f\u7528Array<\/code>\u7684find<\/code>\u65b9\u6cd5\u6765\u67e5\u627e\u88ab\u9009\u4e2d\uff08\u5373\u6b63\u5728\u64ad\u653e\uff09\u7684\u89c6\u9891\u8f68\u9053\uff0c\u7136\u540e\u83b7\u53d6\u5176\u7801\u7387\u3002<\/p>\n
          \u95ee\u98983\uff1a<\/strong> \u6709\u6ca1\u6709\u5176\u4ed6\u65b9\u6cd5\u53ef\u4ee5\u901a\u8fc7JavaScript\u83b7\u53d6\u6d4f\u89c8\u5668\u4e2d\u89c6\u9891\u7684\u7801\u7387\u4fe1\u606f\uff1f<\/p>\n
          \u56de\u7b54\uff1a<\/strong> \u662f\u7684\uff0c\u5728\u4e0d\u652f\u6301\u76f4\u63a5\u83b7\u53d6\u89c6\u9891\u7801\u7387\u7684\u6d4f\u89c8\u5668\u4e2d\uff0c\u8fd8\u53ef\u4ee5\u901a\u8fc7\u8ba1\u7b97\u89c6\u9891\u7684\u4e0b\u8f7d\u901f\u5ea6\u6765\u4f30\u7b97<\/a>\u7801\u7387\u3002\u53ef\u4ee5\u4f7f\u7528HTMLMediaElement<\/code>\u63a5\u53e3\u63d0\u4f9b\u7684buffered<\/code>\u5c5e\u6027\u83b7\u53d6\u5df2\u7f13\u51b2\u7684\u89c6\u9891\u65f6\u957f\uff0c\u7136\u540e\u6839\u636e\u5df2\u7f13\u51b2\u7684\u5b57\u8282\u6570\u4e0e\u6240\u82b1\u8d39\u7684\u65f6\u95f4\u6765\u8ba1\u7b97\u5e73\u5747\u7801\u7387\u3002<\/p>\n
          \u4f8b\u5982\uff0c\u5047\u8bbe\u5df2\u77e5\u89c6\u9891\u7684\u5927\u5c0f\u4e3a100MB\uff0c\u5df2\u7f13\u51b2\u7684\u89c6\u9891\u65f6\u957f\u4e3a10\u79d2\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u4ee3\u7801\u6765\u4f30\u7b97\u5e73\u5747\u7801\u7387\uff1a<\/p>\n
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