RecordRTC：利用WebRTC在Web端录制视频

利用RecordRTC打开手机或者电脑摄像头，进行录像，完成后对视频文件进行压缩。兼容Firefox 17+、Chrome 21+、Edge 12+、Chrome for Android等。

这个只在安卓机适用。如果你是在微信浏览器做录制视频的功能，建议不要使用这种方法。因为录制的视频并没有保存下来，最终传给服务器的文件只剩下390字节的头，视频内容不存在。需要修改底层的RecordRTC.js，我也没有尝试，希望有其他人尝试过，可以留言交流。

一、首先在index.html引入getHTMLMediaElement文件

<script src="https://cdn.webrtc-experiment.com/getHTMLMediaElement.js"></script>

二、下载依赖包

npm i recordrtc

npm i timers

三、在Vue框架可直接使用如下代码块

<template><div class="center">
  <div class="settime">
    还剩：{{sec}} 秒  </div>
  <div v-if="finish" class="finish">
    已录制完成！<br/>请点击右下角上传，或点击中间按钮重新录制  </div>
  <div id="recording-player"></div>
  <button id="btn-start-recording" class="play">
    <span :class="platStatus?'stop': 'start'"></span>
  </button>
  <button class="back" @click="$router.back(-1)">返回</button>
  <button id="save-to-disk" class="save">上传</button></div></template><script>import RecordRTC from 'recordrtc'import { setInterval, clearInterval } from "timers";export default {
  data() {    return {      winWidth: window.innerWidth,      platStatus: false, //按钮显示‘开始’
      saveVideo: false,      sec: 10,      bloburl: '',      interval: '',      finish: false
    }
  },
  created(){
    
  },
  mounted(){    console.log(this.winWidth)    const that = this;    var video = document.createElement('video');
    video.controls = false;    var mediaElement = getHTMLMediaElement(video, {        buttons: ['full-screen', 'take-snapshot'],        showOnMouseEnter: false,        width: that.winWidth,
    });    document.getElementById('recording-player').appendChild(video);    var div = document.createElement('section');
    mediaElement.media.parentNode.appendChild(div);
    div.appendChild(mediaElement.media);    var recordingPlayer = mediaElement.media;    var btnStartRecording = document.querySelector('#btn-start-recording');    var saveRecording = document.querySelector('#save-to-disk');    var mimeType = 'video/webm';    var fileExtension = 'webm';    var recorderType = null;    var type = 'video';    var videoBitsPerSecond = null;    var button = btnStartRecording;    function getURL(arg) {      console.log("getURL:", arg);        var url = arg;        var str = typeof(arg);        // if(arg instanceof Blob || arg instanceof File) {
        //   url = window.URL.createObjectURL(arg);
        // }
        // if(arg instanceof RecordRTC || arg.getBlob) {
        //   url = window.URL.createObjectURL(arg.getBlob());
        // }
        // if(arg instanceof MediaStream || arg.getTracks || arg.getVideoTracks || arg.getAudioTracks) {
        //     // url = URL.createObjectURL(arg);
        // }
        if(str == 'string'){
          that.finish = true;
        }
        that.bloburl = url;        // return url;
    }    function setVideoURL(arg, forceNonImage) {      console.log("setVideoURL")        var url = getURL(arg);        var parentNode = recordingPlayer.parentNode;
        parentNode.removeChild(recordingPlayer);
        parentNode.innerHTML = '';        var elem = 'video';
        recordingPlayer = document.createElement(elem);        if(arg instanceof MediaStream) {
            recordingPlayer.muted = true;
        }
        recordingPlayer.addEventListener('loadedmetadata', function() {            if(navigator.userAgent.toLowerCase().indexOf('android') == -1) return;            // android
            setTimeout(function() {                if(typeof recordingPlayer.play === 'function') {
                    recordingPlayer.play();
                }
            }, 2000);
        }, false);
        recordingPlayer.poster = '';        if(arg instanceof MediaStream) {
            recordingPlayer.srcObject = arg;
        }        else {
            recordingPlayer.src = url;
        }        if(typeof recordingPlayer.play === 'function') {
            recordingPlayer.play();
        }
        
        recordingPlayer.addEventListener('ended', function() {
            url = getURL(arg);            
            if(arg instanceof MediaStream) {
                recordingPlayer.srcObject = arg;
            }            else {
                recordingPlayer.src = url;
            }
        });
        parentNode.appendChild(recordingPlayer);
    }
    
    button.mediaCapturedCallback = function() {      console.log("mediaCapturedCallback")    
        var options = {            type: type,            mimeType: mimeType,            getNativeBlob: false, // enable it for longer recordings
            video: recordingPlayer
        };
        options.ignoreMutedMedia = false;
        button.recordRTC = RecordRTC(button.stream, options);
        button.recordingEndedCallback = function(url) {
            setVideoURL(url);
        };
        button.recordRTC.startRecording();
    
    }    //初始化
    var commonConfig = {        onMediaCaptured: function(stream) {          // that.finish = false;
            button.stream = stream;            if(button.mediaCapturedCallback) {
                button.mediaCapturedCallback();
            }            
            // button.innerHTML = "停止";
            button.disabled = false;
            that.platStatus = true;
            that.interval = setInterval(() => {
              that.sec--;              if (that.sec <= 0) {
                clearInterval(that.interval);
                btnStartRecording.();
              }
            }, 1000);
        },        onMediaStopped: function() {            // button.innerHTML = "开始";
            that.platStatus = false;
            that.sec = 10
            if(!button.disableStateWaiting) {
                button.disabled = false;
            }
        },        onMediaCapturingFailed: function(error) {            console.error('onMediaCapturingFailed:', error);    
            if(error.toString().indexOf('no audio or video tracks available') !== -1) {
                alert('RecordRTC failed to start because there are no audio or video tracks available.');
            }    
            if(DetectRTC.browser.name === 'Safari') return;    
            if(error.name === 'PermissionDeniedError' && DetectRTC.browser.name === 'Firefox') {
                alert('Firefox requires version >= 52. Firefox also requires HTTPs.');
            }
    
            commonConfig.onMediaStopped();
        }
    };    
    //调起摄像头
    function captureUserMedia(mediaConstraints, successCallback, errorCallback) {      console.log("captureUserMedia")        if(mediaConstraints.video == true) {
            mediaConstraints.video = {};
        }
    
        navigator.mediaDevices.getUserMedia(mediaConstraints).then(function(stream) {
            successCallback(stream);
            setVideoURL(stream, true);
        }).catch(function(error) {            if(error && error.name === 'ConstraintNotSatisfiedError') {
                alert('Your camera or browser does NOT supports selected resolutions or frame-rates. \n\nPlease select "default" resolutions.');
            }
            errorCallback(error);
        });
    }    
    function addStreamStopListener(stream, callback) {      console.log("addStreamStopListener")        var streamEndedEvent = 'ended';        if ('oninactive' in stream) {
            streamEndedEvent = 'inactive';
        }
        stream.addEventListener(streamEndedEvent, function() {
            callback();
            callback = function() {};
        }, false);
        stream.getAudioTracks().forEach(function(track) {
            track.addEventListener(streamEndedEvent, function() {
                callback();
                callback = function() {};
            }, false);
        });
        stream.getVideoTracks().forEach(function(track) {
            track.addEventListener(streamEndedEvent, function() {
                callback();
                callback = function() {};
            }, false);
        });
    }    function captureAudioPlusVideo(config) {
      that.finish = false;      console.log(captureAudioPlusVideo)
        captureUserMedia({video: true, audio: true}, function(audioVideoStream) {
            config.onMediaCaptured(audioVideoStream);            if(audioVideoStream instanceof Array) {
                audioVideoStream.forEach(function(stream) {
                    addStreamStopListener(stream, function() {
                        config.onMediaStopped();
                    });
                });                return;
            }
            addStreamStopListener(audioVideoStream, function() {
                config.onMediaStopped();
            });
        }, function(error) {
            config.onMediaCapturingFailed(error);
        });
    }    
    function stopStream() {      console.log("stopStream")        if(button.stream && button.stream.stop) {
            button.stream.stop();
            button.stream = null;
        }    
        if(button.stream instanceof Array) {
            button.stream.forEach(function(stream) {
                stream.stop();
            });
            button.stream = null;
        }
    
        videoBitsPerSecond = null;        var html = 'Recording status: stopped';
        html += '<br>Size: ' + button.recordRTC.getBlob().size;
    }    
    function getFileName(fileExtension) {        var d = new Date().getTime();        // var year = d.getUTCFullYear();
        // var month = d.getUTCMonth() + 1;
        // var date = d.getUTCDate();
        return 'RecordRTC-' + d + '.' + fileExtension;
    }    
    function saveToDiskOrOpenNewTab(recordRTC) {        var fileName = getFileName(fileExtension);
        saveRecording. = function(event) {            if(!recordRTC) return alert('No recording found.');            var file = new File([recordRTC.getBlob()], fileName, {                type: mimeType
            });            console.log(file);            // that.$store.commit("changeAndroidVideo", file);
            // that.$router.back(-1);
            // invokeSaveAsDialog(file, file.name);
        }
    }    //操作录像
    btnStartRecording. = function(event) {
      clearInterval(that.interval);      console.log(that.platStatus)        if(that.platStatus == true) {
            button.disabled = true;
            button.disableStateWaiting = true;
            setTimeout(function() {
                button.disabled = false;
                button.disableStateWaiting = false;
            }, 2000);            // button.innerHTML = "开始";
            that.platStatus = false;
            that.saveVideo = true;            if(button.recordRTC) {                if(button.recordRTC.length) {
                    button.recordRTC[0].stopRecording(function(url) {                        if(!button.recordRTC[1]) {
                            button.recordingEndedCallback(url);
                            stopStream();
                            saveToDiskOrOpenNewTab(button.recordRTC[0]);                            return;
                        }
                        button.recordRTC[1].stopRecording(function(url) {
                            button.recordingEndedCallback(url);
                            stopStream();
                        });
                    });
                }                else {
                    button.recordRTC.stopRecording(function(url) {
                        button.recordingEndedCallback(url);
                        saveToDiskOrOpenNewTab(button.recordRTC);
                        stopStream();
                    });
                }
            }            return;
        }
        captureAudioPlusVideo(commonConfig);
    }
  },  methods: {
    
      
  }
};</script><style scoped>.play{  width: 50px;  height: 50px;  line-height: 52px;  text-align: center;  background-color: #fff;  border: 1px solid #ccc;  border-radius: 50%;  position: absolute;  bottom: 20px;  left: 50%;  margin-left: -25px;  /* color: #fff; */}.start{  display: inline-block;  width: 35px;  height: 35px;  border-radius: 50%;  background-color: #ccc;  margin-top: 6px;
}.stop{  display: inline-block;  width: 15px;  height: 15px;  border-radius: 5px;  background-color: red;  margin-top: 16px;
}.save{  width: 50px;  height: 35px;  line-height: 35px;  text-align: center;  background-color: #fff;  border: 1px solid #ccc;  border-radius: 3px;  position: absolute;  bottom: 25px;  right: 20px;
}.back{  width: 50px;  height: 35px;  line-height: 35px;  text-align: center;  background-color: #fff;  border: 1px solid #ccc;  border-radius: 3px;  position: absolute;  bottom: 25px;  left: 20px;
}.settime{  width: 100%;  height: 40px;  line-height: 40px;  background-color: rgba(0, 0, 0, 0.5);  color: #fff;  text-align: center;
}.finish{  text-align: center;  margin-top: 100px;  padding: 20px;
}</style>

作者：Lucia_Huang

链接：https://www.jianshu.com/p/6971dbdfbcc2