Answers.Body: <p>I met this issue when I'm developing a player. And I checked codes in <a href="https://github.com/Aegisub/Aegisub/blob/master/src/auto4_base.cpp" rel="nofollow noreferrer">Aegisub</a> (line:159). I saw there is a scale from calculated size to real size. I think this is to keep the rendered text height being same with set fontSize. Maybe there's a spec that says something about this.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-08-24T17:44:46.763Z
Answers.LastActivityDate: 2022-08-24T17:44:46.763Z
Answers.UserDisplayName: MaoQ
Body: <p>My final video output is 1080:1920 (9:16 aspect ratio), after padding.</p>
  <p>In .ass file, I set
  PlayResX: 1080
  PlayResY: 1920
  and then the font-size=130. But, this font-size doesnt occupy exact 130 pixels on screen, when I render the video using ffmpeg.</p>
  <p>If my video (in react js UI) width=108px; height=192px; then font-size = 13px (=130*(192/1920)) appear much larger than what 130px looks in 1080px:1920px (in proportion). However, if I multiple 13px by 2/3, I get almost the correct size.</p>
  <p>What is a more robust method of setting font-sizes in .ass (with ffmpeg)?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2022-01-19T09:44:34.930Z
Comments.Text: Did you ever get the solution to this? i have been multiplying the font by 1.4 to make it almost the same but thats just an arbitrary number i found from trial and error.
Comments.UserDisplayName: prasum
Tags: <ffmpeg><video-editor><subtitles>
Title: Correct method to set font-size in .ASS file
UserDisplayName: jsdbt
ThreadText: # Correct method to set font-size in .ASS file
  
  (Asked by: username_0 on 2020-08-31)
  
  My final video output is 1080:1920 (9:16 aspect ratio), after padding.
  
  In .ass file, I set
  PlayResX: 1080
  PlayResY: 1920
  and then the font-size=130. But, this font-size doesnt occupy exact 130 pixels on screen, when I render the video using ffmpeg.
  
  If my video (in react js UI) width=108px; height=192px; then font-size = 13px (=130\*(192/1920)) appear much larger than what 130px looks in 1080px:1920px (in proportion). However, if I multiple 13px by 2/3, I get almost the correct size.
  
  What is a more robust method of setting font-sizes in .ass (with ffmpeg)?
  
  **Tags:** ffmpeg, video-editor, subtitles
  
  > **Comments:**
  > **username_1**: Did you ever get the solution to this? i have been multiplying the font by 1.4 to make it almost the same but thats just an arbitrary number i found from trial and error.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2022-08-24. Score: 0
  
  I met this issue when I'm developing a player. And I checked codes in [Aegisub](https://github.com/Aegisub/Aegisub/blob/master/src/auto4_base.cpp) (line:159). I saw there is a scale from calculated size to real size. I think this is to keep the rendered text height being same with set fontSize. Maybe there's a spec that says something about this.
  
  
  ---
  
  