user11713: I just uploaded a video to Facebook yesterday, and then I tried to download the video as HD, and I realized that Facebook actually re-encode the video even though the original video file doesn't rendered with high bitrate or super HD option.
Original video

File size: 50 Mb
  Length: ~3 mins
  Bitrate: 2 Mbps
  Resolution: 1280x720
  Frame rate: 25 fps
  Reference frame: 8
  Level: 4
  Audio bitrate: 128 Kbps


Uploaded video

File size: 20 Mb
  Length: ~3 mins
  Bitrate: 750 Kbps
  Resolution: 1280x720
  Frame rate: 25 fps
  Reference frame: 5
  Level: 3.1
  Audio bitrate: 48 Kbps

As you can see there's a big loss of quality in the uploaded video. How can I avoid Facebook leave my video untouched? Or it will re-encode the video no matter how small the file size is?

user1871: You can't avoid the re-encode. They do this to be sure that every video they serve is in a standardized format, resolution and bitrate. It would be inefficient and risky to vet all diverse set of incoming files to check if they meet all their parameters, some of which are not easily available to set or tweak at the user's end.

11713: <p>I just uploaded a video to Facebook yesterday, and then I tried to download the video as HD, and I realized that Facebook actually re-encode the video even though the original video file doesn't rendered with high bitrate or super HD option.</p>

<p><strong>Original video</strong><br></p>

<blockquote>
  <p>File size: 50 Mb<br>
  Length: ~3 mins<br>
  Bitrate: <strong>2 Mbps</strong><br>
  Resolution: 1280x720<br>
  Frame rate: 25 fps<br>
  Reference frame: 8<br>
  Level: 4<br>
  Audio bitrate: <strong>128 Kbps</strong></p>
</blockquote>

<p><br>
<strong>Uploaded video</strong><br></p>

<blockquote>
  <p>File size: 20 Mb<br>
  Length: ~3 mins<br>
  Bitrate: <strong>750 Kbps</strong><br>
  Resolution: 1280x720<br>
  Frame rate: 25 fps<br>
  Reference frame: 5<br>
  Level: 3.1<br>
  Audio bitrate: <strong>48 Kbps</strong></p>
</blockquote>

<p>As you can see there's a big loss of quality in the uploaded video. How can I avoid Facebook leave my video untouched? Or it will re-encode the video no matter how small the file size is?</p>
 1871: <p>You can't avoid the re-encode. They do this to be sure that every video they serve is in a standardized format, resolution and bitrate. It would be inefficient and risky to vet all diverse set of incoming files to check if they meet all their parameters, some of which are not easily available to set or tweak at the user's end.</p>
