Answers.Body: <p>Yes, your observation is correct and everything works fine. Even if settings are identitcal, the file hashes will always be different.</p>
  <p>The reason is quite simple: XMP metadata which is embedded in the files.</p>
  <p>Such metadata entries which are often different are:</p>
  <ul>
  <li>time stamps (not only the date but the time too)
  <ul>
  <li>creation date</li>
  <li>modified date</li>
  <li>metadata date</li>
  </ul>
  </li>
  <li>IDs
  <ul>
  <li>document ID</li>
  <li>instance ID</li>
  <li>original document ID</li>
  </ul>
  </li>
  </ul>
  <p>A bit of binary data in the header is different too. All the rest, meaning the actual video and audio data is the same. The encoding algorithms are working deterministic - that means, given the same input they produce the same output. At least those I've tried for my example. This doesn't have to be true in other cases.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-02-08T18:06:42.823Z
Answers.Text: wow, now that you mention it, its obvious. thanks
Answers.UserDisplayName: Joseph
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-02-08T08:53:55.907Z
Answers.LastActivityDate: 2021-02-08T08:53:55.907Z
Answers.UserDisplayName: Matt
Body: <p>When I export an Adobe Premiere project to video twice with the same export settings, why does it yield videos with different file hashes?</p>
  <p>Shouldn't the files be identical and have matching hashes? Where is the source of randomness coming into the encoding process?</p>
  <p><a href="https://i.sstatic.net/Ak0Zw.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Ak0Zw.png" alt="enter image description here" /></a></p>
  <p>The encoding settings</p>
  <p><a href="https://i.sstatic.net/M5cLv.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/M5cLv.png" alt="enter image description here" /></a></p>
  <p>These two files were encoded using identical settings a few seconds apart, note that the files are not actually identical.</p>
  
Tags: <premiere><encoding><adobe><adobe-media-encoder><export>
Title: Exported the same video twice with the same settings yields files with different hashes
UserDisplayName: Joseph
ThreadText: # Exported the same video twice with the same settings yields files with different hashes
  
  (Asked by: username_0 on 2021-02-08)
  
  When I export an Adobe Premiere project to video twice with the same export settings, why does it yield videos with different file hashes?
  
  Shouldn't the files be identical and have matching hashes? Where is the source of randomness coming into the encoding process?
  
  [![enter image description here](https://i.sstatic.net/Ak0Zw.png)](https://i.sstatic.net/Ak0Zw.png)
  
  The encoding settings
  
  [![enter image description here](https://i.sstatic.net/M5cLv.png)](https://i.sstatic.net/M5cLv.png)
  
  These two files were encoded using identical settings a few seconds apart, note that the files are not actually identical.
  
  **Tags:** premiere, encoding, adobe, adobe-media-encoder, export
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2021-02-08. Score: 2 | Accepted answer
  
  Yes, your observation is correct and everything works fine. Even if settings are identitcal, the file hashes will always be different.
  
  The reason is quite simple: XMP metadata which is embedded in the files.
  
  Such metadata entries which are often different are:
  
  * time stamps (not only the date but the time too)
    + creation date
    + modified date
    + metadata date
  * IDs
    + document ID
    + instance ID
    + original document ID
  
  A bit of binary data in the header is different too. All the rest, meaning the actual video and audio data is the same. The encoding algorithms are working deterministic - that means, given the same input they produce the same output. At least those I've tried for my example. This doesn't have to be true in other cases.
  
  > **Comments:**
  > **username_0**: wow, now that you mention it, its obvious. thanks  
  
  ---
  
  