Answers.Body: <p>The audio filters should be chained one after the another. Your syntax generates two audio tracks, each doubled in speed. Also, since you're dealing with one input and one output, you can just use simple filters.</p>
  
  <pre><code>ffmpeg -i 02.mp4 -vf "setpts=0.25*PTS" -af "atempo=2.0,atempo=2.0" 02ff.mp4
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-01-31T20:31:08.840Z
Answers.Text: Thanks, I added the `-strict -2` filter just after the 02.mp4 to get rid of the error ` The encoder 'aac' is experimental but experimental codecs`.  Then everything worked
Answers.UserDisplayName: learningtech
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-02-01T04:39:36.060Z
Answers.Text: That message is for pre-2016 builds of ffmpeg, so you should upgrade.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-01-31T20:24:42.283Z
Answers.LastActivityDate: 2019-01-31T20:24:42.283Z
Answers.UserDisplayName: Gyan
Body: <p>I have a video file and I want to quadruple the video and audio play speed. I followed the instructions here</p>
  
  <p><a href="https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video" rel="nofollow noreferrer">https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video</a></p>
  
  <p>So I tried these commands:</p>
  
  <pre><code>ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4
  </code></pre>
  
  <p>This command quadrupled the video play speed but only doubled the audio play speed.</p>
  
  <p>So then I tried this:</p>
  
  <pre><code>ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0,atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4
  </code></pre>
  
  <p>But still the same issue.  I've tried a few other variations of this command but I just get errors.</p>
  
  <p>What's the correct command to quadruple video play spdd and audio play speed?</p>
  
Tags: <ffmpeg>
Title: ffmpeg quadruple video and audio play speed
UserDisplayName: learningtech
ThreadText: # ffmpeg quadruple video and audio play speed
  
  (Asked by: username_0 on 2019-01-31)
  
  I have a video file and I want to quadruple the video and audio play speed. I followed the instructions here
  
  <https://trac.ffmpeg.org/wiki/How%20to%20speed%20up%20/%20slow%20down%20a%20video>
  
  So I tried these commands:
  
  ```
  ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4
  
  ```
  
  This command quadrupled the video play speed but only doubled the audio play speed.
  
  So then I tried this:
  
  ```
  ffmpeg -i 02.mp4 -strict -2 -filter_complex "[0:v]setpts=0.25*PTS[v];[0:a]atempo=2.0[a];[0:a]atempo=2.0,atempo=2.0[a]" -map "[v]" -map "[a]" -map "[a]" 02ff.mp4
  
  ```
  
  But still the same issue. I've tried a few other variations of this command but I just get errors.
  
  What's the correct command to quadruple video play spdd and audio play speed?
  
  **Tags:** ffmpeg
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2019-01-31. Score: 3 | Accepted answer
  
  The audio filters should be chained one after the another. Your syntax generates two audio tracks, each doubled in speed. Also, since you're dealing with one input and one output, you can just use simple filters.
  
  ```
  ffmpeg -i 02.mp4 -vf "setpts=0.25*PTS" -af "atempo=2.0,atempo=2.0" 02ff.mp4
  
  ```
  
  > **Comments:**
  > **username_0**: Thanks, I added the `-strict -2` filter just after the 02.mp4 to get rid of the error ` The encoder 'aac' is experimental but experimental codecs`.  Then everything worked  
  > **username_1**: That message is for pre-2016 builds of ffmpeg, so you should upgrade.  
  
  ---
  
  