{"id":91605,"date":"2024-04-09T18:32:27","date_gmt":"2024-04-09T10:32:27","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/91605.html"},"modified":"2024-04-09T18:32:28","modified_gmt":"2024-04-09T10:32:28","slug":"%e5%9c%a8javascript%e4%b8%ad%e5%a4%84%e7%90%86%e8%a7%86%e9%a2%91%e6%b5%81","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/91605.html","title":{"rendered":"\u5728JavaScript\u4e2d\u5904\u7406\u89c6\u9891\u6d41"},"content":{"rendered":"

\"\u5728JavaScript\u4e2d\u5904\u7406\u89c6\u9891\u6d41\"<\/p>\n

\u5728JavaScript\u4e2d\u5904\u7406\u89c6\u9891\u6d41\u4e3b\u8981\u6d89\u53ca\u83b7\u53d6\u89c6\u9891\u8f93\u5165\u3001\u6d41\u64cd\u4f5c\u4ee5\u53ca\u89c6\u9891\u6d41\u5c55\u793a<\/strong>\u3002JavaScript<\/strong>\u63d0\u4f9b\u4e86\u4e00\u5957\u7075\u6d3b\u7684APIs\uff0c\u5982MediaDevices<\/strong>\u63a5\u53e3\uff0c\u5b83\u5141\u8bb8\u7528\u6237\u4ece\u591a\u5a92\u4f53\u786c\u4ef6\u8bbe\u5907\uff08\u5982\u6444\u50cf\u5934\u548c\u9ea6\u514b\u98ce\uff09\u83b7\u53d6\u5a92\u4f53\u8f93\u5165\u3002\u8fdb\u4e00\u6b65\u7684\uff0c\u6d41\u64cd\u4f5c\u90e8\u5206<\/strong>\uff0c\u53ef\u4ee5\u901a\u8fc7MediaStream API\u5904\u7406\u548c\u64cd\u4f5c\u8fd9\u4e9b\u89c6\u9891\u6d41\uff0c\u5b9e\u73b0\u4f8b\u5982\u89c6\u9891\u7279\u6548\u3001\u89c6\u9891\u5f55\u5236\u7b49\u590d\u6742\u529f\u80fd\u3002\u6b64\u5916\uff0c\u89c6\u9891\u6d41\u7684\u5c55\u793a\u901a\u5e38\u5229\u7528HTML\u7684<video><\/code>\u5143\u7d20\u6765\u5b9e\u73b0\uff0c\u901a\u8fc7\u8bbe\u7f6e\u5176srcObject<\/code>\u5c5e\u6027\u4e3a\u83b7\u53d6\u7684MediaStream\u5bf9\u8c61\uff0c\u4fbf\u53ef\u4ee5\u5728\u7f51\u9875\u4e0a\u663e\u793a\u89c6\u9891\u6d41\u5185\u5bb9\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u83b7\u53d6\u89c6\u9891\u8f93\u5165<\/h3>\n<\/p>\n

\u8981\u5728JavaScript\u4e2d\u5904\u7406\u89c6\u9891\u6d41\uff0c\u9996\u8981\u4efb\u52a1\u662f\u4ece\u7528\u6237\u7684\u8bbe\u5907\u4e2d\u83b7\u53d6\u89c6\u9891\u8f93\u5165\u3002\u8fd9\u901a\u5e38\u901a\u8fc7navigator.mediaDevices.getUserMedia()\u65b9\u6cd5\u5b9e\u73b0\uff0c\u8be5\u65b9\u6cd5\u63d0\u793a\u7528\u6237\u5141\u8bb8\u6216\u62d2\u7edd\u4f7f\u7528\u89c6\u9891\uff08\u548c\/\u6216\u97f3\u9891\uff09\u8bbe\u5907\uff0c\u5982\u6444\u50cf\u5934\u3002<\/p>\n<\/p>\n

\u9996\u5148\uff0c\u4f60\u9700\u8981\u6784\u5efa\u4e00\u4e2a\u5408\u9002\u7684constrAI<\/a>nts<\/strong>\u5bf9\u8c61\uff0c\u6307\u5b9a\u4f60\u5e0c\u671b\u83b7\u53d6\u7684\u5a92\u4f53\u7c7b\u578b\u548c\u53c2\u6570\u3002\u5bf9\u4e8e\u89c6\u9891\uff0c\u53ef\u4ee5\u6307\u5b9a\u5e0c\u671b\u7684\u5e27\u7387\u3001\u5206\u8fa8\u7387\u7b49\uff1a<\/p>\n<\/p>\n

const constraints = {<\/p>\n
  video: {<\/p>\n
    width: { ideal: 1280 },<\/p>\n
    height: { ideal: 720 },<\/p>\n
    frameRate: { ideal: 30 }<\/p>\n
  }<\/p>\n
};<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u63a5\u7740\uff0c\u901a\u8fc7\u8c03\u7528navigator.mediaDevices.getUserMedia()<\/code>\u5e76\u4f20\u5165constraints\u5bf9\u8c61\uff0c\u8fd4\u56de\u4e00\u4e2aPromise\uff0c\u5b83\u89e3\u6790\u4e00\u4e2aMediaStream\u5bf9\u8c61\uff0c\u8be5\u5bf9\u8c61\u901a\u8fc7\u89c6\u9891\u8bbe\u5907\uff08\u5982\u6444\u50cf\u5934\uff09\u83b7\u5f97\u7684\u89c6\u9891\u6d41\u3002<\/p>\n<\/p>\n
navigator.mediaDevices.getUserMedia(constraints)<\/p>\n
  .then(function(stream) {<\/p>\n
    \/\/ \u4f7f\u7528stream<\/p>\n
  })<\/p>\n
  .catch(function(err) {<\/p>\n
    console.error('\u83b7\u53d6\u89c6\u9891\u6d41\u5931\u8d25', err);<\/p>\n
  });<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001\u6d41\u64cd\u4f5c<\/h3>\n<\/p>\n
\u83b7\u5f97\u89c6\u9891\u6d41\u540e\uff0c\u4f60\u53ef\u80fd\u9700\u8981\u8fdb\u884c\u5404\u79cd\u64cd\u4f5c\uff0c\u5982\u89c6\u9891\u753b\u9762\u7684\u5b9e\u65f6\u5904\u7406\u3001\u6dfb\u52a0\u6c34\u5370\u3001\u89c6\u9891\u5f55\u5236<\/strong>\u7b49\u3002\u8fd9\u4e9b\u64cd\u4f5c\u53ef\u4ee5\u901a\u8fc7Canvas API<\/strong>\u4ee5\u53caMediaRecorder API<\/strong>\u6765\u5b9e\u73b0\u3002<\/p>\n<\/p>\n
\u89c6\u9891\u5b9e\u65f6\u5904\u7406<\/h4>\n<\/p>\n
\u53ef\u4ee5\u4f7f\u7528Canvas API<\/strong>\u5bf9\u89c6\u9891\u6d41\u8fdb\u884c\u5b9e\u65f6\u5904\u7406\uff0c\u6bd4\u5982\u5b9e\u65f6\u6539\u53d8\u89c6\u9891\u4e2d\u7684\u989c\u8272\u3001\u5e94\u7528\u6ee4\u955c\u7b49\u3002\u9996\u5148\uff0c\u4f60\u9700\u8981\u5c06\u89c6\u9891\u6d41\u7ed8\u5236\u5230canvas\u4e0a\uff0c\u7136\u540e\u901a\u8fc7\u64cd\u4f5ccanvas\u7684pixel\u6570\u636e\u6765\u5b9e\u73b0\u5404\u79cd\u56fe\u50cf\u5904\u7406\u6548\u679c\u3002<\/p>\n<\/p>\n
function processVideo(stream) {<\/p>\n
  const video = document.createElement('video');<\/p>\n
  const canvas = document.createElement('canvas');<\/p>\n
  const ctx = canvas.getContext('2d');<\/p>\n
  video.srcObject = stream;<\/p>\n
  video.play();<\/p>\n
  video.onloadedmetadata = function() {<\/p>\n
    canvas.width = video.videoWidth;<\/p>\n
    canvas.height = video.videoHeight;<\/p>\n
    requestAnimationFrame(tick);<\/p>\n
  };<\/p>\n
  function tick() {<\/p>\n
    ctx.drawImage(video, 0, 0, canvas.width, canvas.height);<\/p>\n
    \/\/ \u5728\u8fd9\u91cc\u5904\u7406canvas\u56fe\u50cf...<\/p>\n
    requestAnimationFrame(tick);<\/p>\n
  }<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u89c6\u9891\u5f55\u5236<\/h4>\n<\/p>\n
MediaRecorder API<\/strong>\u5141\u8bb8\u4f60\u8f7b\u677e\u5730\u5f55\u5236\u89c6\u9891\u6d41\u3002\u9996\u5148\uff0c\u4f60\u9700\u8981\u521b\u5efa\u4e00\u4e2aMediaRecorder<\/code>\u5b9e\u4f8b\uff0c\u5c06\u89c6\u9891\u6d41\u4f5c\u4e3a\u53c2\u6570\u4f20\u9012\u7ed9\u5b83\u3002\u7136\u540e\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528start\u3001stop\u7b49\u65b9\u6cd5\u6765\u63a7\u5236\u5f55\u5236\u8fc7\u7a0b\u3002<\/p>\n<\/p>\n
function recordVideo(stream) {<\/p>\n
  let recorder = new MediaRecorder(stream);<\/p>\n
  let data = [];<\/p>\n
  recorder.ondataavailable = event => data.push(event.data);<\/p>\n
  recorder.onstop = () => {<\/p>\n
    \/\/ \u5904\u7406\u5f55\u5236\u597d\u7684\u89c6\u9891\u6570\u636e<\/p>\n
  };<\/p>\n
  recorder.start();<\/p>\n
  \/\/ \u5728\u9002\u5f53\u7684\u65f6\u5019\u8c03\u7528recorder.stop()\u505c\u6b62\u5f55\u5236<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001\u89c6\u9891\u6d41\u5c55\u793a<\/h3>\n<\/p>\n
\u6700\u540e\uff0c\u5c55\u793a\u89c6\u9891\u6d41\u76f8\u5bf9\u6bd4\u8f83\u76f4\u63a5\u3002\u5c06MediaStream\u5bf9\u8c61\u8d4b\u503c\u7ed9HTML\u7684<video><\/code>\u5143\u7d20\u7684srcObject<\/code>\u5c5e\u6027\uff0c\u89c6\u9891\u4fbf\u53ef\u4ee5\u5728\u7f51\u9875\u4e0a\u5c55\u793a\u3002<\/p>\n<\/p>\n
function displayVideo(stream) {<\/p>\n
  const videoElement = document.createElement('video');<\/p>\n
  document.body.appendChild(videoElement);<\/p>\n
  videoElement.srcObject = stream;<\/p>\n
  videoElement.play();<\/p>\n
}<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u603b\u4e4b\uff0c\u901a\u8fc7\u4f7f\u7528JavaScript\u7684\u591a\u5a92\u4f53\u5904\u7406API\uff0c\u4f60\u53ef\u4ee5\u5b9e\u73b0\u4ece\u83b7\u53d6\u89c6\u9891\u8f93\u5165\u3001\u5bf9\u89c6\u9891\u6d41\u8fdb\u884c\u5404\u79cd\u64cd\u4f5c\uff0c\u5230\u6700\u7ec8\u5728\u7f51\u9875\u4e0a\u5c55\u793a\u89c6\u9891\u6d41\u7684\u6574\u4e2a\u8fc7\u7a0b\u3002\u8fd9\u4e9b\u6280\u672f\u7684\u5e94\u7528\u975e\u5e38\u5e7f\u6cdb\uff0c\u80fd\u591f\u652f\u6301\u5b9e\u65f6\u901a\u4fe1\u3001\u89c6\u9891\u4f1a\u8bae\u3001\u5728\u7ebf\u6559\u80b2\u7b49\u591a\u79cd\u73b0\u4ee3\u7f51\u7edc\u5e94\u7528\u7684\u5f00\u53d1\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
1. \u5982\u4f55\u5728JavaScript\u4e2d\u6355\u83b7\u89c6\u9891\u6d41\u5e76\u8fdb\u884c\u5904\u7406\uff1f<\/strong><\/p>\n
\u6355\u83b7\u89c6\u9891\u6d41\u5e76\u8fdb\u884c\u5904\u7406\u662f\u5728JavaScript\u4e2d\u5904\u7406\u89c6\u9891\u7684\u5e38\u89c1\u9700\u6c42\u3002\u4f60\u53ef\u4ee5\u4f7f\u7528navigator.mediaDevices.getUserMedia()<\/code>\u65b9\u6cd5\u6765\u8bbf\u95ee\u7528\u6237\u7684\u6444\u50cf\u5934\u5e76\u6355\u83b7\u89c6\u9891\u6d41\u3002\u4e00\u65e6\u83b7\u5f97\u89c6\u9891\u6d41\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528<video><\/code>\u5143\u7d20\u5c06\u5176\u663e\u793a\u5728\u7f51\u9875\u4e0a\uff0c\u5e76\u4f7f\u7528canvas<\/code>\u5143\u7d20\u6216WebGL\u8fdb\u884c\u8fdb\u4e00\u6b65\u7684\u5904\u7406\u3002<\/p>\n
2. \u6709\u54ea\u4e9b\u5e38\u7528\u7684JavaScript\u5e93\u53ef\u4ee5\u7528\u4e8e\u5904\u7406\u89c6\u9891\u6d41\uff1f<\/strong><\/p>\n
\u5728JavaScript\u793e\u533a\u4e2d\u6709\u8bb8\u591a\u4f18\u79c0\u7684\u5e93\u53ef\u4ee5\u5e2e\u52a9\u4f60\u5904\u7406\u89c6\u9891\u6d41\u3002\u4e00\u4e9b\u5e38\u7528\u7684\u5e93\u5305\u62ec\uff1a<\/p>\n