javascript - 我正在使用媒体记录器捕获屏幕并从 blob 制作视频，但该视频未显示其持续时间

Question

我正在使用媒体记录器捕获屏幕并从 blob 制作视频，但该视频没有显示它的持续时间我已经尝试了所有方式但无法获得持续时间。我使用了getID3（PHP）但没有工作我使用了许多其他方法，但只有一种方法对我有用，我在下面定义了两个步骤：|

var vid = document.createElement("video");
vid.src = url;
object.addEventListener("loadedmetadata", function() {
                                if(vid.duration === Infinity) {
                                    vid.currentTime = 1000000000; 
                                }  
                            });

                            var duration = 0;
                            var speed_factor = 0.0;
                            object.addEventListener("timeupdate", function() {
                                duration = vid.duration;
                                if(duration <= 10.0)
                                {
                                    speed_factor = 1.0;
                                }else if(duration <= 30.0)
                                {
                                    speed_factor = 1.5;
                                }else if(duration <= 60.0)
                                {
                                    speed_factor = 2.0;
                                }else if(duration <= 120.0)
                                {
                                    speed_factor = 3.0;
                                }else if(duration <= 180.0)
                                {
                                    speed_factor = 4.0;
                                }else if(duration <= 240.0)
                                {
                                    speed_factor = 5.0;
                                }else{
                                    speed_factor = 10.0;
                                }
                                $("#source1").attr("src", url);
                                $("#source2").attr("src", url);
                                
                                $("#videoplayer").get(0).defaultPlaybackRate = speed_factor;
                                console.log("The video duration is "+ duration+" and speed factor is "+speed_factor);

                                $('#videoplayer').get(0).load();
                                $('#videoplayer').get(0).play();
                            });