Answers.Body: <p>Use</p>
  
  <pre><code>-af "volume=enable='gte(t,30)*lt(mod(t,30),3)':volume=0"
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-02T15:43:19.287Z
Answers.Text: Can you explain the parameters for me? Thank you so much
Answers.UserDisplayName: Monso
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-02T16:12:47.773Z
Answers.Text: `lt(mod(t,30),3)` selects first 3 seconds of every 30 seconds, `gte(t,30)` starts selection from  t=30s, so that the first 3 seconds (0-3) aren't selected.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-06-02T12:32:33.773Z
Answers.LastActivityDate: 2018-06-02T12:52:22.543Z
Answers.LastEditDate: 2018-06-02T12:52:22.543Z
Answers.UserDisplayName: Gyan
Body: <p>I have the code below I want it to automatically increment up like this:<br>
  <code>(t, 30,33)</code> and <code>(t, 60,63)</code>, <code>(t, 90,93)</code> and so on it adds <code>30</code> units.</p>
  
  <pre><code>     ffmpeg -i in.mov -vcodec copy -af "volume=enable='between(t,30,33)':volume=0"out2.mov
  </code></pre>
  
Tags: <ffmpeg>
Title: Increase volume with ffmpeg
UserDisplayName: Monso
ThreadText: # Increase volume with ffmpeg
  
  (Asked by: username_0 on 2018-06-02)
  
  I have the code below I want it to automatically increment up like this:  
  `(t, 30,33)` and `(t, 60,63)`, `(t, 90,93)` and so on it adds `30` units.
  
  ```
       ffmpeg -i in.mov -vcodec copy -af "volume=enable='between(t,30,33)':volume=0"out2.mov
  
  ```
  
  **Tags:** ffmpeg
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2018-06-02. Score: 2 | Accepted answer
  
  Use
  
  ```
  -af "volume=enable='gte(t,30)*lt(mod(t,30),3)':volume=0"
  
  ```
  
  > **Comments:**
  > **username_0**: Can you explain the parameters for me? Thank you so much  
  > **username_1**: `lt(mod(t,30),3)` selects first 3 seconds of every 30 seconds, `gte(t,30)` starts selection from  t=30s, so that the first 3 seconds (0-3) aren't selected.  
  
  ---
  
  