CreateObjectURL jquery/js | realize the capture of video clips? Blob save to server?

$(document).on("change", ".uploadVideo", function() {
  var video = this.files[0];
  var videoUrl = window.URL.createObjectURL(video);

I did an upload
to the blob address, like this:

blob:http://localhost/367a4312-f142-4646-8a8d-7c0674e60413

question 1
I would like to ask whether there is a way to obtain a video file. Is a certain segment of that film or a video segment of that movie considered to be truncated?
is very much like youtube. If you don"t decide on the truncation, it will automatically stop you to grab a certain segment as a truncation

question 2
suppose I upload many blob: http://localhost/367a4312-f142-4646-8a8d-7c0674e60413 addresses at the same time, how to do an one-time upload?

preg_match("/^(data:\s*image\/(\w+);base64,)/", $crop_result, $result);
$fileType = "." . $result[2];
file_put_contents($uploadPathIcon."HEELLOO" . $fileType, base64_decode(str_replace($result[1], "", $crop_result)));

this is the data: video network address obtained by readAsDataURL of FileReader , just like blob , but I don"t know if these users can be used, so I can download it to the server.