Answers.Body: <p><code>setpts</code> filter can be used to retime frames. Basic usage is</p>
  
  <pre><code>ffmpeg -i in -vf setpts=PTS*2 out.mp4
  </code></pre>
  
  <p><code>PTS*2</code> sets output timestamp of each frame to 2x its input value.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-09-11T08:53:17.237Z
Answers.LastActivityDate: 2018-09-11T08:53:17.237Z
Answers.UserDisplayName: Gyan
Body: <p>The video has length of t and is 30fps. I want it to have a length of 2*t.
  I just want each frame to be shown a little longer. According to VLC the codec is H264-MPEG4 AVC.
  Is there some simple command with ffmpeg?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-09-11T07:50:06.343Z
Comments.Text: Any audio present?
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2018-09-11T07:51:20.820Z
Comments.Text: No audio. I may add some later.
Comments.UserDisplayName: Pesho
Tags: <ffmpeg>
Title: How to double every frame (and the length of the video itself) in an mp4 video (timelapse)?
UserDisplayName: Pesho
ThreadText: # How to double every frame (and the length of the video itself) in an mp4 video (timelapse)?
  
  (Asked by: username_0 on 2018-09-11)
  
  The video has length of t and is 30fps. I want it to have a length of 2\*t.
  I just want each frame to be shown a little longer. According to VLC the codec is H264-MPEG4 AVC.
  Is there some simple command with ffmpeg?
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: Any audio present?  
  > **username_0**: No audio. I may add some later.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-09-11. Score: 0 | Accepted answer
  
  `setpts` filter can be used to retime frames. Basic usage is
  
  ```
  ffmpeg -i in -vf setpts=PTS*2 out.mp4
  
  ```
  
  `PTS*2` sets output timestamp of each frame to 2x its input value.
  
  
  ---
  
  