title: .mp4 file uploaded from react-native won't play in chrome
body: <p>I have a situation where I am recorded a video via expo / react-native and uploaded it to a s3 bucket. However, when I access the s3 link in the browser, the video will not play. However, the video will play in VLC media player if i download it first. I'm not sure why the video won't play in chrome (or any other browser). The expected behavior is the link will play in the browser.</p>
  
  <p>Steps to reproduce:</p>
  
  <ol>
  <li>Record video via react-native (this will save the video as a .mov file)</li>
  <li>"Convert" the file to .mp4 by using Expo's FileSystem.moveAsync() to rename the file to .mp4</li>
  <li>Upload to s3 (with mime type video/mp4)</li>
  <li>Open the s3 link in the browser:</li>
  </ol>
  
  <p><a href="https://i.stack.imgur.com/Itt6n.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Itt6n.png" alt="enter image description here"></a></p>
  
  <p>However, if I download the video an open it in VLC, it will play fine. Does anyone know what's going on? </p>
  
  <p>Note - I was inspired by this SO to convert .mov to .mp4 by simply changing the file's extension <a href="https://stackoverflow.com/questions/12548304/how-can-i-convert-mov-to-mp4-on-ios-device/12589999#12589999">How can I convert mov to mp4 on ios device</a></p>
  
  <p>Link to the file:
  <a href="https://sandbox-of-sandboxes.s3.amazonaws.com/iKmlKprIs.mp4" rel="nofollow noreferrer">https://sandbox-of-sandboxes.s3.amazonaws.com/iKmlKprIs.mp4</a></p>