tencent cloud

async function combine(readableVideos, destination) {
  for (const readable of readableVideos) {
    // Send a streaming response.
    await readable.pipeTo(destination, {
      preventClose: true
    });
  }

  const writer = destination.getWriter();
  writer.close();
  writer.releaseLock();
}

async function handleRequest(request) {
  // The URLs of the video clips.
  const urls = [
    'https://laputa-1257579200.cos.ap-guangzhou.myqcloud.com/stream-01.mov',
    'https://laputa-1257579200.cos.ap-guangzhou.myqcloud.com/stream-02.mov',
    'https://laputa-1257579200.cos.ap-guangzhou.myqcloud.com/stream-03.mov',
  ];

  const requests = urls.map(url => fetch(url));
  const responses = await Promise.all(requests);
  // Obtain the readable streams of the video clips.
  const readableVideos = responses.map(res => res.body);

  const { readable, writable } = new TransformStream();
  // Merge the video clips.
  combine(readableVideos, writable);

  return new Response(readable, {
    headers: {
      'content-type': 'video/mp4',
    }
  });
}

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request));
});