Answers.Body: <p>I just found a way to do this by changing the parameters help by <strong>fps</strong> <strong>tbr</strong> <strong>tbn</strong> <strong>tbc</strong>; answer is derived from <a href="https://stackoverflow.com/a/52713677/6500909">this post</a>.</p>
  
  <p><code>ffmpeg -y -i at25fps.mov -c:v copy -video_track_timescale 16 at16fps.mov</code></p>
  
  <p>I am getting these remarks from Apple Sound Media Handler (so I am not sure if this is the best way to do it)</p>
  
  <blockquote>
    <p>Non-monotonous DTS in output stream 0:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.</p>
    
    <p>Non-monotonous DTS in output stream 0:0; previous: 1, current: 1; changing to 2. This may result in incorrect timestamps in the output file.</p>
    
    <p>...</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-01-26T21:20:32.990Z
Answers.LastActivityDate: 2019-01-26T21:47:39.787Z
Answers.LastEditDate: 2019-01-26T21:47:39.787Z
Answers.UserDisplayName: MeSo2
Body: <p>This works to change the speed, but it also changes the codec to MPEG4 Video (H264). </p>
  
  <p><code>ffmpeg -y -r 16 -i at25fps.mov -filter:v "setpts=25/16*PTS" at16fps.mov</code></p>
  
  <p>I need the codec to stay untouched: prores (HQ) (apch / 0x68637061), yuv422p10le(tv, progressive).</p>
  
  <p>I found many similar post, but nothing worked:
  <a href="https://video.stackexchange.com/questions/23674/how-to-change-framerate-with-ffmpeg-without-re-encoding">How to change framerate with ffmpeg without re-encoding?</a>, 
  <a href="https://video.stackexchange.com/questions/21431/lower-framerate-without-re-encode">Lower framerate without re-encode</a></p>
  
  <p><a href="https://superuser.com/questions/1159056/ffmpeg-recreate-timestamps-without-reencoding/1358974#1358974">This post</a> suggest I first extract the raw stream - how would I do that for a ProRes file?</p>
  
Tags: <video><ffmpeg><framerate><prores>
Title: How to slow down ProRes file from 25fps to 16fps without re-encoding?
UserDisplayName: MeSo2
ThreadText: # How to slow down ProRes file from 25fps to 16fps without re-encoding?
  
  (Asked by: username_0 on 2019-01-26)
  
  This works to change the speed, but it also changes the codec to MPEG4 Video (H264).
  
  `ffmpeg -y -r 16 -i at25fps.mov -filter:v "setpts=25/16*PTS" at16fps.mov`
  
  I need the codec to stay untouched: prores (HQ) (apch / 0x68637061), yuv422p10le(tv, progressive).
  
  I found many similar post, but nothing worked:
  [How to change framerate with ffmpeg without re-encoding?](https://video.stackexchange.com/questions/23674/how-to-change-framerate-with-ffmpeg-without-re-encoding),
  [Lower framerate without re-encode](https://video.stackexchange.com/questions/21431/lower-framerate-without-re-encode)
  
  [This post](https://superuser.com/questions/1159056/ffmpeg-recreate-timestamps-without-reencoding/1358974#1358974) suggest I first extract the raw stream - how would I do that for a ProRes file?
  
  **Tags:** video, ffmpeg, framerate, prores
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2019-01-26. Score: 0 | Accepted answer
  
  I just found a way to do this by changing the parameters help by **fps** **tbr** **tbn** **tbc**; answer is derived from [this post](https://stackoverflow.com/a/52713677/6500909).
  
  `ffmpeg -y -i at25fps.mov -c:v copy -video_track_timescale 16 at16fps.mov`
  
  I am getting these remarks from Apple Sound Media Handler (so I am not sure if this is the best way to do it)
  
  > Non-monotonous DTS in output stream 0:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
  >
  > Non-monotonous DTS in output stream 0:0; previous: 1, current: 1; changing to 2. This may result in incorrect timestamps in the output file.
  >
  > ...
  
  
  ---
  
  