Ошибка безопасности Firefox: содержимое по адресу http://localhost:NNNN/ может не загружать данные из blob: http://localhost:NNNN/... при назначении URL-адреса BLOB-объекта MediaSource

const video = document.querySelector('video');
const mediaSource = new MediaSource();
const url = URL.createObjectURL(mediaSource);
video.src = url;

<video controls></video>

const video = document.querySelector('video');
const mediaSource = new MediaSource();
setTimeout(() => {
  video.src = URL.createObjectURL(mediaSource);
});

<video controls></video>

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

'use strict';

// This code adapted from Eric Bidelman's demo at
// http://html5-demos.appspot.com/static/media-source.html

var FILE = 'https://upload.wikimedia.org/wikipedia/commons/a/a4/BBH_gravitational_lensing_of_gw150914.webm';
var NUM_CHUNKS = 5;
var video = document.querySelector('video');

if (!window.MediaSource) {
  alert('The MediaSource API is not available on this platform');
}

const fakeMain = { postMessage(data) { fakeWorker.onmessage?.({ data }); } };
const fakeWorker = { postMessage(data) { fakeMain.onmessage?.({ data }); } };

fakeWorker.onmessage = (message) => {
  console.info('received message', message);
  switch (message.data.type) {
    case 'init': {
      console.info('received message in worker');
      const mediaSource = new MediaSource();
      mediaSource.addEventListener(
        'sourceopen',
        function () {
          var sourceBuffer = mediaSource.addSourceBuffer(
            'video/webm; codecs = "vorbis,vp8"'
          );
          console.info(sourceBuffer);

          log('MediaSource readyState: ' + this.readyState);

          get(FILE, function (uInt8Array) {
            var file = new Blob([uInt8Array], {
              type: 'video/webm',
            });
            var chunkSize = Math.ceil(file.size / NUM_CHUNKS);

            log('Number of chunks: ' + NUM_CHUNKS);
            log('Chunk size: ' + chunkSize + ', total size: ' + file.size);

            // Slice the video into NUM_CHUNKS and append each to the media element.
            var i = 0;

            (function readChunk_(i) {
              // eslint-disable-line no-shadow
              var reader = new FileReader();

              // Reads aren't guaranteed to finish in the same order they're started in,
              // so we need to read + append the next chunk after the previous reader
              // is done (onload is fired).
              reader.onload = function (e) {
                sourceBuffer.appendBuffer(new Uint8Array(e.target.result));
                log('Appending chunk: ' + i);
                if (i === NUM_CHUNKS - 1) {
                  sourceBuffer.addEventListener('updateend', function () {
                    if (
                      !sourceBuffer.updating &&
                      mediaSource.readyState === 'open'
                    ) {
                      mediaSource.endOfStream();
                    }
                  });
                } else {
                  if (video.paused) {
                    video.play(); // Start playing after 1st chunk is appended.
                  }
                  readChunk_(++i);
                }
              };

              var startByte = chunkSize * i;
              var chunk = file.slice(startByte, startByte + chunkSize);

              reader.readAsArrayBuffer(chunk);
            })(i); // Start the recursive call by self calling.
          });
        },
        false
      );

      mediaSource.addEventListener(
        'sourceended',
        function () {
          log('MediaSource readyState: ' + this.readyState);
        },
        false
      );
      const url = window.URL.createObjectURL(mediaSource);
      fakeWorker.postMessage({ type: 'setSrc', url });
    }
  }
};

fakeMain.onmessage = (message) => {
  switch (message.data.type) {
    case 'setSrc': {
      console.info('received message in main');

      video.src = message.data.url;
    }
  }
};

document.querySelector('[data-num-chunks]').textContent = NUM_CHUNKS;
fakeMain.postMessage({ type: 'init' });
function get(url, callback) {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', url, true);
  xhr.responseType = 'arraybuffer';
  xhr.send();

  xhr.onload = function () {
    if (xhr.status !== 200) {
      alert('Unexpected status code ' + xhr.status + ' for ' + url);
      return false;
    }
    callback(new Uint8Array(xhr.response));
  };
}

function log(message) {
  document.getElementById('data').innerHTML += message + '<br /><br />';
}

<video controls></video>
<div data-num-chunks></div>
<div id = "data"></div>