Body: <p>I am trying to overlay a logo on a video, and reveal it gradually. I used the following command:</p>
  
  <pre><code>$ ffmpeg -i uploads/vid1.mp4 -loop 1 -r 25 -pix_fmt yuva420p -i logo.png -filter_complex "[1]drawbox=x=0:color=black:w=in_w*if(lt(t\,2)\,(2-t)/2\,0.01):thickness=fill:replace=1[L1];[0][L1]overlay=eof_action=endall" vidout.mp4
  
  $ ffmpeg -version
  ffmpeg version 4.1.3-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  ...
  </code></pre>
  
  <p>As far as I understand, drawbox should have timeline support:</p>
  
  <pre><code>$ ffmpeg -filters|grep drawbox
  ....
   T.. drawbox           V-&gt;V       Draw a colored box on the input video.
  </code></pre>
  
  <p>Instead of revealing the logo gradually, it displays the full logo immediately. How can I reveal the logo gradually?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-02T11:32:58.317Z
Comments.Text: drawbox does not have animation support.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-12-02T14:42:34.587Z
Comments.Text: Thanks for the reply, @Gyan. What can I use to animate a logo on a video?
Comments.UserDisplayName: Hemanth
Tags: <ffmpeg>
Title: Trying to reveal a logo gradually
UserDisplayName: Hemanth
ThreadText: # Trying to reveal a logo gradually
  
  (Asked by: username_0 on 2019-12-02)
  
  I am trying to overlay a logo on a video, and reveal it gradually. I used the following command:
  
  ```
  $ ffmpeg -i uploads/vid1.mp4 -loop 1 -r 25 -pix_fmt yuva420p -i logo.png -filter_complex "[1]drawbox=x=0:color=black:w=in_w*if(lt(t\,2)\,(2-t)/2\,0.01):thickness=fill:replace=1[L1];[0][L1]overlay=eof_action=endall" vidout.mp4
  
  $ ffmpeg -version
  ffmpeg version 4.1.3-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  ...
  
  ```
  
  As far as I understand, drawbox should have timeline support:
  
  ```
  $ ffmpeg -filters|grep drawbox
  ....
   T.. drawbox           V->V       Draw a colored box on the input video.
  
  ```
  
  Instead of revealing the logo gradually, it displays the full logo immediately. How can I reveal the logo gradually?
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: drawbox does not have animation support.  
  > **username_0**: Thanks for the reply, @username_1. What can I use to animate a logo on a video?  
  
  ---
  
  ## 0 answers
  
  