title: Vimeo: merge some clips together
body: <p>Vimeo provides an API that allows uploading video in JS. I'm uploading video using the resumable approach and it requires <a href="https://developer.vimeo.com/api/upload/videos#resumable-approach-step-1" rel="nofollow noreferrer">knowing how many bytes</a> this video contains. And it's easy to implement when a user upload only one file and it's easy to extract.</p>
  <p>Today I need to implement the following logic: I need to ask some questionы to a user and they have 30 sec to record a video answering it. After that, I need to merge those clips somehow and upload them to Vimeo.
  Is there anybody who already implemented this?</p>
  <ul>
  <li>should I keep these clips in memory and after that calculate how many bytes they take and upload via tus protocol (but I'm afraid here that I have a limitation on how many memory I may use)</li>
  <li>is there any other way to upload each clip separately in Vimeo and afterwards to combine them in one via some their API (I have not found it)</li>
  </ul>
  <p>Thank you for any help here.</p>