title: Why some of the MP4 file's mime-type are application/octet-stream instead of video/mp4?
body: <p>Why some of the MP4 file's mime-type are application/octet-stream instead of video/mp4?</p>
  
  <p>I've checked with file command in terminal (CLI)</p>
  
  <pre><code>user@anto:~/Videos/VTB$ file --mime-type -b GDPR.mp4 
  video/mp4
  user@anto:~/Videos/VTB$ file --mime-type -b Test-vid1.mp4 
  application/octet-stream
  user@anto:~/Videos/VTB$ file --mime-type -b SampleVideoLarge.mov 
  video/quicktime
  user@anto:~/Videos/VTB$ file --mime-type -b SampleVideo21.mp4 
  video/mp4
  user@anto:~/Videos/VTB$ file --mime-type -b VTBSample-new.mp4 
  application/octet-stream.
  </code></pre>
  
  <p>Can anyone tell me the reason? How to handle this mime-type. Is the video file with <strong>application/octet-stream</strong> is a correct mp4 file or wrong one? </p>